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[B]1. Lava & Magma[/B] Magma is the molten rock material deep inside earths crust, while the same magma, when it finds its way to a volcano through fissures and cracks, and comes out of the mouth of the volcano, is referred to as lava. So magma is deep underground, while lava is the hot mixture of gases and molten rocks that comes out of the volcano. The most notable difference between magma and lava pertains to their location. [B]2. Fold & Fault[/B] [B][U][COLOR="purple"]Fold:[/COLOR][/U][/B] A fold is a bend in a rock layer caused by forces within the crust of the earth. Folds usually occur in a series and look like waves in the rock. [B][U][COLOR="purple"]Fault:[/COLOR][/U][/B] Rock layers can also break, in which case a fault occurs. A fault zone is where the sides of broken rock have moved relative to each other. [B]3. Caustic Soda and Caustic Potash[/B] Sodium hydroxide (NaOH) and potassium hydroxide (KOH) are both strongly alkaline, corrosive solids. As chemical re-agents, they are mostly interchangeable, although some differences exist in specific applications. [B][U][COLOR="purple"]1. Chemistry in Air[/COLOR][/U][/B] o Sodium hydroxide, also known as lye or caustic soda, and potassium hydroxide, also known as caustic potash, are both white solids. They are hygroscopic, meaning they will absorb water from the air. Sodium hydroxide will form sodium carbonate (Na₂CO₃, washing soda) by absorption of carbon dioxide (CO₂): 2 NaOH + CO₂ ' Na₂CO₃ + H₂O Potassium hydroxide, however, will form potassium bicarbonate (KHCO₃): KOH + CO₂ ' KHCO₃ [B][U][COLOR="purple"]2. Solubility[/COLOR][/U][/B] o Sodium and potassium hydroxide are strong bases. At room temperature, they exhibit almost identical solubilities in water - 111 grams of sodium hydroxide will dissolve in 100 millilitres of water vs. 110 grams of potassium hydroxide. [B][U][COLOR="purple"]Applications[/COLOR][/U][/B] o Both hydroxides can be used in the saponification of fats to form soap. Soaps prepared from potassium hydroxide tend to exhibit greater solubility and are commonly referred to as "soft" soaps. [B][U][COLOR="purple"]Manufacture[/COLOR][/U][/B] o Sodium and potassium hydroxides are prepared commercially by electrolysis of sodium chloride (NaCl, table salt) or potassium chloride (KCl): 2 NaCl + H₂O ' H₂ + Cl₂ + NaOH 2 KCl + H₂O ' H₂ + Cl₂ + KOH [B][U][COLOR="purple"]Differences[/COLOR][/U][/B] o In many applications, potassium and sodium hydroxide can be freely interchanged. The primary difference between them is cost. In ton quantities, potassium hydroxide is about three times more expensive than sodium hydroxide. [B]4. SEM & TEM[/B] [B][U][COLOR="purple"]SEM:[/COLOR][/U][/B] SEM involves shooting an electron beam at a specimen and observing the reactions on the specimen surface. When the electron hits a molecule on the surface, its energy is absorbed by the molecule, which in turn emits a lower amount of energy. This energy can be in the form of a secondary, less energetic electron, a photon of light, or x-rays. Differentiation between these emissions is used to produce image contrast. However, in order to produce a coherent image, the sample must often be prepared with a conductive coating or by embedding a resin for many biological samples. [B][U][COLOR="purple"]TEM: [/COLOR][/U][/B] TEM acts much like a typical bright field microscope in the sense that it sends electrons through a specimen. As it propagates through the specimen, some of the electrons are scattered and some are transmitted. The transmitted electrons is passed through an objective lens and then projected onto a scintillating material which can then be recorded photographically. This requires samples to be prepared in very thin slices in order to allow transmission of the electrons through transparent sections. [B][U][CENTER][COLOR="purple"]OR[/COLOR][/CENTER][/U][/B] A SEM (scanning electron microscope) images using the electrons reflected from a specimen. A TEM (transmission electron microscope) images using the electrons that pass through it. The image from an SEM thus looks somewhat like a normal photo (we're used to imaging using the light reflected from objects). However, a TEM image takes a bit more interpretation as we're not used to seeing images of light that's passed through things - think of silhouettes or slide projectors. |
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[B]1. Periscope & Pyrometer:[/B] [B][U][COLOR="purple"]Periscope:[/COLOR][/U][/B] Instrument used by submarines to see above the surface of the sea. [B][U][COLOR="purple"]Pyrometer:[/COLOR][/U][/B] Instrument used for measuring high temperatures. [B]2. Cell & Battery[/B] [B][U][COLOR="purple"]Cell:[/COLOR][/U][/B] A cell is a DC voltage source in which chemical energy is converted into electricity. [B][U][COLOR="purple"]Battery:[/COLOR][/U][/B] It is a device which produces electricity through the use of acid and other chemicals. It is assembly of many cells. [B]3. Perimeter & Altimeter[/B] [B][U][COLOR="purple"]Perimeter:[/COLOR][/U][/B] A perimeter is a path that surrounds an area. The word comes from the Greek peri (around) and meter (measure). The term may be used either for the path or its length - it can be thought of as the length of the outline of a shape. The perimeter of a circular area is called circumference. [B][U][COLOR="purple"]Altimeter:[/COLOR][/U][/B] An altimeter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth underwater. [B]4. Pelage & Plumage[/B] [B][U][COLOR="purple"]Pelage:[/COLOR][/U][/B] It is a growth of hair/fur/wool covering the skin of animals. [B][U][COLOR="purple"]Plumage:[/COLOR][/U][/B] Plumages are feathers covering the body of birds. [B]5. Smog & Smoke[/B] [B][U][COLOR="purple"]Smog[/COLOR][/U][/B] Smog is formed by the interaction of pollutants present in the air in presence of sun light (photochemical smog), it usually restricts visibility and is hazardous to health. [B][U][COLOR="purple"]Smoke: [/COLOR][/U][/B] Smoke is the thin fine particles usually result from the combustion. |
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[B]1. Radiotherapy & Chemotherapy[/B] 1.Β Radiation targets only the cancer cells. However, chemotherapy is administered through the blood and therefore, affects both cancerous and non-cancerous cells 2. Though they can be used for any sort of cancer, radiation mainly targets solid tumours like those of the cervix, spine and skin. 3. Chemotherapy treats cancers through medicines, while radiation deals with cancer cells through rays 4. Radiation results in additional side effects like internal inflammation, especially in the stomach and the intestine. [B]2. Springtides & Neap tides[/B] [B][U][COLOR="purple"]Springtide:[/COLOR][/U][/B] i) Spring Tides When the moon is full or new, the gravitational pull of the moon and sun are combined. ii) At these times, the high tides are very high and the low tides are very low. This is known as a spring high tide. iii) Spring tides are especially strong tides (they do not have anything to do with the season spring). iv) They occur when the Earth, the Sun, and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. v) Spring tides occur during the full moon and the new moon. [B][U][COLOR="purple"]Neap tides:[/COLOR][/U][/B] i) Neap Tides During the moon's quarter phases the sun and moon work at right angles, causing the bulges to cancel each other. ii) The result is a smaller difference between high and low tides and is known as a neap tide. iii) Neap tides are especially weak tides. iv) They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). v) Neap tides occur during quarter moon. [B]3. Penumbra & Umbra (already described in paper 2002)[/B] [B]4. Vertebrates & Invertebrates [/B] Vertebrates have a backbone with a spinal cord, whereas invertebrates do not. The diversity is exceptionally high among the invertebrates compared to vertebrates. Vertebrates are always bilaterally symmetrical, while invertebrates could show either bilateral or radial symmetry. Vertebrates are usually large-bodied and move fast compared to invertebrates. Vertebrates have a closed blood system, a well-developed brain, either gills or lungs for respiration, and a complex and sophisticated nervous system, whereas those are primitive in invertebrates. Therefore, it concerns that vertebrates have many specializations to extract the best out of the environment compared to invertebrates. [B]5. Fluorescent & Neon Light[/B] A neon light is the sort of light you see used in advertising signs. These signs are made of long, narrow glass tubes, and these tubes are often bent into all sorts of shapes. The tube of a neon light can spell out a word, for example. These tubes emit light in different colours. A fluorescent light, on the other hand, is most often a long, straight tube that produces white light. You see fluorescent lights in offices, stores and some home fixtures. The idea behind a neon light is simple. Inside the glass tube there is a gas like neon, argon or krypton at low pressure. At both ends of the tube there are metal electrodes. When you apply a high voltage to the electrodes, the neon gas ionizes, and electrons flow through the gas. These electrons excite the neon atoms and cause them to emit light that we can see. Neon emits red light when energized in this way. Other gases emit other colours. A fluorescent light works on a similar idea but it has an extra step. Inside a fluorescent light is low-pressure mercury vapour. When ionized, mercury vapour emits ultraviolet light. Human eyes are not sensitive to ultraviolet light (although human skin is -- see How Sunburns and Sun Tans Work!). Therefore, the inside of a fluorescent light is coated with a phosphor. A phosphor is a substance that can accept energy in one form (for example, energy from a high-speed electron as in a TV tube -- see How Television Works) and emit the energy in the form of visible light. In a fluorescent lamp, the phosphor accepts the energy of ultraviolet photons and emits visible photons. The light we see from a fluorescent tube is the light given off by the phosphor that coats the inside of the tube (the phosphor fluoresces when energized, hence the name). The light of a neon tube is the colored light that the neon atoms give off directly. |
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[B]1. Telemeter and Multimeter [/B] [B][U][COLOR="purple"]Telemeter:[/COLOR][/U][/B] A telemeter is a device used to remotely measure a quantity. Telemeters are generally the physical devices used in telemetry. Electronic devices are widely used in telemetry and can be wireless or hard-wired, analogue or digital. Other technologies are possible, however, such as mechanical, hydraulic and optical. [B][U][COLOR="purple"]Multimeter:[/COLOR][/U][/B] A multimeter or a multi-tester, also known as a VOM (Volt-Ohm meter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current and resistance. Multimeters may use analogue or digital circuitsanalogue multimeters (AMM) and digital multimeters (often abbreviated DMM or DVOM.) Analog instruments are usually based on a micro-ammeter whose pointer moves over a scale calibrated for all the different measurements that can be made; digital instruments usually display digits, but may display a bar of a length proportional to the quantity being measured. A multimeter can be a hand-held device useful for basic fault finding and field service work or a bench instrument which can measure to a very high degree of accuracy. They can be used to troubleshoot electrical problems in a wide array of industrial and household devices such as electronic equipment, motor controls, domestic appliances, power supplies, and wiring systems. [B]2. Perimeter & Altimeter (already described in 2004)[/B] [B]3. Periscope and Microscope[/B] [B][U][COLOR="purple"]Periscope:[/COLOR][/U][/B] A periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle. This form of periscope, with the addition of two simple lenses, served for observation purposes in the trenches during World War I. Military personnel also use periscopes in some gun turrets and in armoured vehicles. More complex periscopes, using prisms instead of mirrors, and providing magnification, operate on submarines. The overall design of the classical submarine periscope is very simple: two telescopes pointed into each other. If the two telescopes have different individual magnification, the difference between them causes an overall magnification or reduction. [B][U][COLOR="purple"]Microscope:[/COLOR][/U][/B] A microscope (from the Greek: μικρός, mikrσs, "small" and σκοπεῖν, skopeξn, "to look" or "see") is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy. Microscopic means invisible to the eye unless aided by a microscope. There are many types of microscopes, the most common and first to be invented is the optical microscope which uses light to image the sample. Other major types of microscopes are the electron microscope (both the transmission electron microscope and the scanning electron microscope) and the various types of scanning probe microscope. [B]4. Nucleon and Photon [/B] [B][U][COLOR="purple"]Nucleon:[/COLOR][/U][/B] A nucleon is a collective name for two particles: the neutron and the proton. These are the two constituents of the atomic nucleus. Until the 1960s, the nucleons were thought to be elementary particles. Now they are known to be composite particles, each made of three quarks bound together by the so-called strong interaction. The interaction between two or more nucleons is called inter-nucleon interactions or nuclear force, which is also ultimately caused by the strong interaction. (Before the discovery of quarks, the term "strong interaction" referred to just inter-nucleon interactions.) [B][U]Photon:[/U][/B] A photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic. It is also the force carrier for the electromagnetic force. The effects of this force are easily observable at both the microscopic and macroscopic level, because the photon has no rest mass; this allows for interactions at long distances. Like all elementary particles, photons are currently best explained by quantum mechanics and will exhibit waveparticle duality, exhibiting properties of both waves and particles. For example, a single photon may be refracted by a lens or exhibit wave interference with itself, but also act as a particle giving a definite result when quantitative momentum (quantized angular momentum) is measured. [B]5. Cusec and Comet[/B] [B][U][COLOR="purple"]Cusec;[/COLOR][/U][/B] Cusec is a measure of flow rate and is informal shorthand for cubic feet per second (28.317 litres per second). [B][U][COLOR="purple"]Comet:[/COLOR][/U][/B] A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma (a thin, fuzzy, temporary atmosphere) and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometres across and are composed of loose collections of ice, dust, and small rocky particles. Comets have been observed since ancient times and have traditionally been considered bad omens. |
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[B](a) BIT and BYTE ( see 1997) (b) RAM and ROM (see 1997) (c) Epidemic and endemic (see 1995) (d) Photosynthesis and respiration (see 1995) (e) Herbivores and carnivores (see 1995)[/B] |
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[B]1. Fission and fusion (see 1996) 2. Star and Planet (see 1996) 3. Pollination and Fertilization (see 1995)[/B] [B]4. Telescope and Microscope[/B] Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near. It is indeed true both the instruments are used to watch the minute details of the objects or things more clearly. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments. As a result of this the focal point in the case of a telescope may be at a far off place. On the other hand the focal point in the case of a microscope is just a fraction of an inch off. The difference in the diameter of the lens used in the two instruments also matter a lot when it comes to the difference between them. The lens diameter or the aperture is much larger in a telescope. This is to ensure that the aperture allows tiny amount of natural light at the focal point. On the other hand only artificial illumination is used in a microscope. The artificial illumination is made to fall at the focal point in a microscope. It is interesting to note that a telescope and a microscope differ from each other in terms of the curvature of the lens. A microscope is used to look into smaller details like the structure of the cells and the unicellular organism. On the other hand larger objects that are very far off are the targets of a telescope. In short it can be said that a telescope is used to look into space. Magnification is the keyword in both the scientific instruments. [B]5. Antibiotics and Vaccines[/B] 1) Vaccine kills virus while antibiotics kill bacteria. 2) Vaccine is taken once and has permanent effect whereas antibiotics work during the time of disease. 3) Antibiotics are available in different forms like tablets, capsules, drops or ointments. Vaccines can be given orally or through injection. 4) Vaccines are preventive method that is taken before getting infected. Antibiotics are taken after getting infected. [B][U][CENTER][SIZE="4"][COLOR="purple"]OR[/COLOR][/SIZE][/CENTER][/U][/B] - Vaccines act against most microorganism, whereas antibiotics act against bacteria. - Vaccines are provided before the manifestation of the infection, but antibiotics are given mostly after. - Vaccines usually have a specific single type of microbe, whereas antibiotics would act against a multitude of species. - Vaccines enhance the natural immunity, and antibiotics cause destruction of the biochemistry of the organism. - Vaccines are highly effective against organism, but there may be resistance to antibiotics needing the development of newer antibiotics. - Both have equally lethal complications, but vaccines carry a lesser range of complications related to antibiotics. |
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[B]1. Umbra and Penumbra (see 2002) 2. Heavy water and hard water (see 99) 3. Smog and Smoke (see 2004)[/B] [B]4. Myopia & Hyperopia[/B] [B][U][COLOR="purple"]Myopia:[/COLOR][/U][/B] Myopia (short sightedness) is an eye disease in which the patient cannot see the distant objects clearly. This disease can be corrected by using convex lenses in glasses. [B][U][COLOR="purple"]Hyperopia: [/COLOR][/U][/B] Hyperopia (long sightedness) is defect of vision in which a person cannot see the clearly objects lying close to him. The disease can be corrected by using convex lenses in glasses. [B]5. Lava and Magma (see 2003)[/B] [B]6. Periscope & Perimeter [/B] [B][U][COLOR="purple"]Periscope: [/COLOR][/U][/B]Instrument used by submarines to see above the surface of the sea. [B][U][COLOR="purple"]Perimeter:[/COLOR][/U][/B] A perimeter is a path that surrounds an area. The word comes from the Greek peri (around) and meter (measure). The term may be used either for the path or its length - it can be thought of as the length of the outline of a shape. The perimeter of a circular area is called circumference. [B]7. X-rays & Gamma Rays[/B] 1. Gamma rays cause more harm to human body than the X- rays. 2. Gamma rays have shorter wavelengths than the X-rays. 3. X rays are emitted by the electrons outside the nucleus, and gamma rays are emitted by the excited nucleus itself. 4. X rays are used in hospitals for taking X-rays but gamma rays are not. |
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[B]1. Hydrometer & Hygrometer[/B] [B][U][COLOR="purple"]Hydrometer[/COLOR][/U][/B] Hydrometer is an instrument used to measure the specific gravity of liquids. It should be noted that specific gravity is the ration of the density of the liquids to density of water. [B][U][COLOR="purple"]Hygrometer:[/COLOR][/U][/B] A hygrometer is an instrument used to measure relative humidity. A simple form of hygrometer consists of two thermometers, one of which has a dry bulb and the other, a wet bulb. [B]2. Perimeter & Telemeter[/B] [B][U][COLOR="purple"]Perimeter:[/COLOR][/U][/B] A perimeter is a path that surrounds an area. The word comes from the Greek peri (around) and meter (measure). The term may be used either for the path or its length - it can be thought of as the length of the outline of a shape. The perimeter of a circular area is called circumference. [B][U][COLOR="purple"]Telemeter:[/COLOR][/U][/B] A telemeter is a device used to remotely measure a quantity. Telemeters are generally the physical devices used in telemetry. Electronic devices are widely used in telemetry and can be wireless or hard-wired, analogue or digital. Other technologies are possible, however, such as mechanical, hydraulic and optical. [B]3. Isotope & Isomer[/B] [B][U][COLOR="purple"]Isotope:[/COLOR][/U][/B] Isotopes are different types of atoms of same element whose atoms of same element whose atomic number is same but atomic mass is different. Isotopes have similar chemical properties but different physical properties. [B][U][COLOR="purple"]Isomers:[/COLOR][/U][/B] Isomers are compounds with the same molecular formula but different structural formula. Isomers do not necessarily share similar properties unless they have same functional groups. [B][U][CENTER][COLOR="purple"]OR[/COLOR][/CENTER][/U][/B] [B][U][COLOR="purple"]Isotopes and Isomers[/COLOR][/U][/B] An isotope refers strictly to pure elements. Atoms of the same element that have different numbers of neutrons in their nuclei are called isotopes. For instance, hydrogen-1 (1H) and hydrogen-2 (2H or deuterium) are isotopes of each other. An isomer refers strictly to molecules. Two molecules that have the same composition (i.e., the same molecular formula) but are different in the connectivity, shape or orientation, are called isomers. For instance, n-propanol (1-propanol) and isopropanol (2-propanol or rubbing alcohol) are isomers of each other. Ethanol is not an isomer of propanol, however, because they have different formulas. [B]4. Flying Mammal & Bird[/B] [B][U][COLOR="purple"]Flying Mammals:[/COLOR][/U][/B] i. Mammals are the class of animals which give birth to live offspring and feed their young ones on milk from their breast. ii.Flying mamma is the type of animal which belongs to mammalian group with additional quality of flying. iii.Bats are representative animals of this group. iii.Bats have many unusual characteristics. v.They cannot walk very well because of skin that reaches over its front and back legs. vi. It flies at night and stays in caves and other dark places during the day. vii.Hanging upside down by the claws of its back legs, it looks like flying mice. [B][U][COLOR="purple"]Birds:[/COLOR][/U][/B] i. Birds are winged, bipedal, endothermic warm-blooded, egg laying vertebrate animals. ii.There are around 10,000 living species across the world. iii.All birds have fore-limbs modified as wings and most can fly with few exceptions like ratites, penguins and number of various island species. [B][U][CENTER][COLOR="purple"]OR[/COLOR][/CENTER][/U][/B] [B][U][COLOR="purple"]Difference between Bats and Birds[/COLOR][/U][/B] The variation between bats and birds is their structure and class. Bats came from the Chiroptera and Aves family. Bats are webbed structured flying animals while birds are feathered winged animals. Bats are mammals, so they dont lay eggs, compared to birds that are known as egg-laying animals. When flying, bats dont flap their forelimbs completely compared to birds. Generally, bats have teeth which help them when eating while birds have beaks in picking up food and eating them. Bats are nocturnal animals; they hunt and go around their business at night and sleep during the day while birds work and hunt for food during daytime and sleep at night. [B]5. Vertebrates & Invertebrates (see 2005)[/B] |
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[B]1. Typhoons & Tornado[/B] Hurricane (also called typhoons) is a result of tropical disturbance on a water body, while a tornado is always formed on land. A tropical storm is labelled a hurricane if it takes place between Atlantic and Pacific Ocean, but the same storm is called a cyclone if it takes place in Indian Ocean. Though both have eyes or centre, the centre of a tornado can be huge, extending up to 20 miles in diameter, whereas the eye of a tornado is very small being only a few feet in diameter Hurricanes occur in the months of June to November, whereas Tornados occur in the months of April to June Tornados last for a few minutes or hours, whereas hurricanes can have a very long duration lasting for 2-3 weeks. Thunderstorms are effects of hurricanes, whereas they are the cause of a tornado Hurricanes can cause floods and tsunamis, whereas tornados spread epidemics and also contaminate water sources. [B][U][FONT="Georgia"][SIZE="4"][COLOR="purple"]OR[/COLOR][/SIZE][/FONT][/U][/B] A tornado is a violently rotating column of air extending from the base of a thunderstorm to the ground. In weather terms tornadoes are small, 50 yards wide on average and rarely exceeding a mile wide, though on rare occasions tornadoes up to 2.5 miles wide have occurred. Tornadoes are also short lived, lasting 10 minutes on average, though a few have lasted for over 3 hours. Tornadoes form from interactions of air currents in a thunderstorm. Hurricanes and typhoons are essentially the same thing, only a hurricane is in the Atlantic ocean or north-eastern Pacific ocean while a typhoon is in the north western Pacific ocean. Both are tropical cyclones with winds of at least 74 mph. In addition to having strong winds these storms bring heavy rain and flooding. The average hurricane/ typhoon is about 300 miles wide and forms over the course of several days. Unlike tornadoes, which are generally as land-based event These systems develop from disorganized clusters of thunderstorms that feed of the moisture from warm ocean water, organize, and intensify. [B]2. Microscope & Telescope[/B] Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near. It is indeed true both the instruments are used to watch the minute details of the objects or things more clearly. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments. As a result of this the focal point in the case of a telescope may be at a far off place. On the other hand the focal point in the case of a microscope is just a fraction of an inch off. The difference in the diameter of the lens used in the two instruments also matter a lot when it comes to the difference between them. The lens diameter or the aperture is much larger in a telescope. This is to ensure that the aperture allows tiny amount of natural light at the focal point. On the other hand only artificial illumination is used in a microscope. The artificial illumination is made to fall at the focal point in a microscope. It is interesting to note that a telescope and a microscope differ from each other in terms of the curvature of the lens. A microscope is used to look into smaller details like the structure of the cells and the unicellular organism. On the other hand larger objects that are very far off are the targets of a telescope. In short it can be said that a telescope is used to look into space. Magnification is the keyword in both the scientific instruments. [B]3. Ultrasonics & Infrasonic:[/B] [B][U][COLOR="purple"]Ultrasonics:[/COLOR][/U][/B] The study of sound aves with high frequencies beyond the upper limit of human hearing or 20 thousand Hz. This technique is employed to locate a tumour, to scan a pregnant womans abdomen in order to produce a picture of foetus or to treat certain neurotically disorders. [B][U][COLOR="purple"]Infrasonic:[/COLOR][/U][/B] These are the sound waves which have the frequencies lowest than the lowest limits of human hearing or 20 Hz. [B][U][COLOR="purple"][FONT="Georgia"][SIZE="4"]OR[/SIZE][/FONT][/COLOR][/U][/B] The sounds having frequency more than 20,000 hertz (Hz) are called ultrasonic or ultrasound and the sounds having frequency less than 20 Hz are called infrasonic or infrasound. Both of these sounds cannot be heard by human beings. The audible range for of hearing by human beings is 20 Hz to 20000 Hz. [B]4. Heavy & Hard Water (see 1999)[/B] [B]5. Isotope & Isomer (see 2010)[/B] [B]6. Antibodies & Antibiotics: [U][COLOR="purple"]Antibodies:[/COLOR][/U][/B] Protein synthesized in the blood in response to the entry of foreign substances or organisms into the body. When the body get infected through virus or bacteria, specific antibody is produced which fights the disease. [B][U][COLOR="purple"]Antibiotics:[/COLOR][/U][/B] These are substances which can stop the growth or destroy the bacteria or other microorganisms. The antibiotics are used to eliminate fatal diseases such as typhoid, plague and cholera etc. [B][U][COLOR="purple"][SIZE="4"]OR[/SIZE][/COLOR][/U][/B] [B][U][COLOR="purple"]Antibodies [/COLOR][/U][/B] l They are what your body produces in response to the presence of antigens (bacterial or viral surface structures) l They merely assist your white blood cells in identifying l They also destroy and invade the unidentified microorganisms. [B][U][COLOR="purple"]Antibiotics[/COLOR][/U][/B] l They are chemicals that work to destroy invading bacteria (usually by disrupting the outer cell wall and making it "leak" or by messing up the bacteria's metabolic processes. They are not produced by the body) l Antibiotics can be antibacterial or antiviral. Antibacterial will only destroy bacteria and antiviral will only destroy viruses. There are not many antibiotics for viruses. Also a virus is not a eukaryote. [B]7. Antigen & Vaccine[/B] [B][U][COLOR="purple"]Antigen:[/COLOR][/U][/B] A substance or organism that induces the production of an antibody. The antigen reacts with antibody. The antigen tissue proteins can cause problems in the transplant of organs by rejecting the introduction of new organ in the body. An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as pollen or cells such as bacteria. The term originally came from antibody generator[1][2] and was a molecule that binds specifically to an antibody, but the term now also refers to any molecule or molecular fragment that can be bound by a major histocompatibility complex (MHC) and presented to a T-cell receptor. "Self" antigens are usually tolerated by the immune system; whereas "Non-self" antigens are identified as invaders and attacked by the immune system. self-antigens. [B][U][COLOR="purple"]Vaccine:[/COLOR][/U][/B] The agent which is used to give immunity against various diseases. A vaccine consists of modified disease organisms such as live weakened viruses or dead that can induce the production of antibodies within the blood. A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins. The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters. Vaccines can be prophylactic (example: to prevent or ameliorate the effects of a future infection by any natural or "wild" pathogen), or therapeutic (e.g. vaccines against cancer are also being investigated; see cancer vaccine). |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Solar System[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
The solar system is the family of the sun, planets revolving around it, the satellites of the planets and the asteroids or meteoroids and comets etc. There are eight planets in the solar system. Starting from the sun there are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. All the planets revolve around the sun in their orbits. Meteorite analysis shows that the age of solar system is about 4530 million years. The sun is not the largest star of the Milky Way; rather it is an average sized star. It is not at the centre of the galaxy but shifted towards a side. The diameter of the sun is 1, 392, 140 km and its mass is 2 * 1027 tonnes. The outermost layer of the sun is called photosphere, has an average temperature of 5570 0C. The photosphere rotates at a rate of 25.38 days per turn. At the centre of the sun hydrogen is undergoing nuclear fusion reaction which provides energy for the heat and light so sun. The planets of the solar system as well as the moons get light and sometimes heat from the sun. The four inner planets of the solar system are called terrestrial plants because of their rocky nature. The outer planets are called gaseous planets because they dont have solid surface and are composed of gases. [CENTER][FONT="Georgia"][SIZE="5"][B][U][COLOR="purple"]Planets And Their Characteristics:[/COLOR][/U][/B][/SIZE][/FONT][/CENTER] [B][U][COLOR="purple"]1. Mercury[/COLOR][/U][/B] Its distance from Sun is 58 million kms. Its revolution period is 88 days. Its rotation period is 58 days, 15 hours and 30 minutes. It has no moon. It is the nearest planet to the sun. It is also the smallest planet of the solar system. It is the fastest planet. Its radius is 2,433 kms and diameter is 4,878 kms. It is covered with holes called Craters. It has no atmosphere. The temperature on mercury vary between 420 0C (7900F) in the day and -180 0C (-2900F) at nights. [B][U][COLOR="purple"]2. Venus[/COLOR][/U][/B] Apart from the moon, Venus is the brightest object in the sky. Venus can be seen with naked eye in the morning or in the evening. Following are the main characteristics of the Venus. Its distance from the Sun is 108 million kms. Its revolution period is 224.7/225 days. Its rotation period is 243 days and 14 hours (longest day) It has no moon. It is the nearest neighbour of the earth in the solar system. It is the brightest planet. It is also the hottest planet. Its diameter is 12,102 kms. It is wrapped in thick clouds of CO2 gas. It rotates from east to west as opposite to most other planets. [B][U][COLOR="purple"]3. Earth[/COLOR][/U][/B] The earth is the largest and the densest of the four terrestrial planets. It is the most wonderful planet of the solar system. Following are the features of the Earth. Its distance from the Sun is 150 million kms. Its revolution period is 365 Ό days. Its rotation period is 23 hours, 56 minutes, 40 seconds. It has one moon. It is the densest planet. It is also the watery and bios planet. Its diameter is 12756 km (7927 miles equatorial and 7900 miles polar diameter) It has atmosphere which contains 78% Nitrogen, and 21% Oxygen. Its two-thirds surface is covered with oceans. The earths surface is rich in Oxygen, Silicon, Aluminium, Iron, Calcium, Sodium etc. [B][U][COLOR="purple"]4. Mars[/COLOR][/U][/B] Distance form sun 228 million kms. Revolution period 687 days. Rotation period 24 h, 37 min and 22 sec. It has two moons Phobos and Deimos. Its diameter is 6794 kms. Mars is covered with red dust. It has an atmosphere composed almost entirely of CO2. Its average temperature is -53 0C. [B][U][COLOR="purple"]5. Jupiter[/COLOR][/U][/B] Its distance from sun is 778 million kms. Revolution period 12 years. Rotation period 9h, 50min, and 30 sec. (smallest day) It has 63 moons. It is the largest planet of the solar system. It has the largest number of satellites. Its diameter is 1, 24,800 kms. Its diameter is eleven times greater than the earths diameter. It has a dense, cloudy atmosphere of hydrogen and helium. It has a rock-iron-ice core about 15, 000 km (9,000 miles) thick. Jupiter radiates 67% more heat than it receives from the sun. this is mainly due to dissipation of the primordial heat of the planet. [B][U][COLOR="purple"]6. Saturn[/COLOR][/U][/B] In 1610, Galileo became the first person to look at Saturn through telescope. Distance from Sun 1427 million kms. Revolution period 30 years. Rotation period 10h, 14 mins. It has 62 moons. The largest moon of Saturn is the Titan and it is the second-largest moon in the solar system. Titan is larger than the planet Mercury. It is the second largest planet. It has a magnificent system of rings. Its diameter is 1, 20, 000 km. [B][U][COLOR="purple"]7. Uranus[/COLOR][/U][/B] When sky is very dark and very clear Uranus can be seen with the naked eyes. The planet was discovered by William Herschel in March 1787. Its distance from Sun is 2869.9 million kms. Revolution period is 84 years. Rotation period is 16h, and 10 mins. It has 27 moons. Titania is the largest moon of Uranus. It has an atmosphere which is dominated by hydrogen and helium. Its diameter is 52, 400 km. [B][U][COLOR="purple"]8. Neptune[/COLOR][/U][/B] Neptune was discovered by the German astronomer Johann Galle. Distance from Sun 4496, 6 million kms. Revolution period 165 years (largest year) Rotation period 18 hours. Neptune has 13 moons that we know of. The largest moon is Triton. It is the coldest planet. It is the slowest to move around the sun. Its diameter is 49,100 kms. It is known as the twin of Uranus due to their similarity of size, mass and composition. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Short Note (Solar System)[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[SIZE="4"][COLOR="purple"][B][U]Lunar Eclipse:[/U][/B][/COLOR][/SIZE] The partial or complete obscuration of light of moon for an observer on the earth is called lunar eclipse. Lunar eclipse takes place when the earth comes in position between the sun and the moon. In this way, the shadow of the earth is cast on the moon and the moon does not get sunlight in this position. Lunar eclipse occurs only when there is full moon. But this does not happen on every full moon because of inclination of the axis of earth to its orbit. [B][U][SIZE="4"][COLOR="purple"]Solar Eclipse:[/COLOR][/SIZE][/U][/B] Solar eclipse occurs when the moon comes in between the Sun and the earth and its shadow is cast across the face of the earth. The solar eclipse occurs when the moon moves to a position between the Sun and the Earth. During this process it throws shadow on the earth. This shadow is categorized in umbral and penumbra. The people who are in the umbral region are unable to see the sun at all. This condition is known as the total eclipse of the sun. While the people in penumbra region can see the sun partly this is known as the partial eclipse of the sun. This happens with the new moon when the moon is in conjunction with the sun. this does not happen at every new moon because of the inclination of the orbit of the moon to the orbit of earth around the sun. [B][U][SIZE="4"][COLOR="purple"]Asteroids:[/COLOR][/SIZE][/U][/B] Asteroids are also known as planetoids. These are small, irregularly shaped rocky objects which orbit the Sun between the orbits of Mars and Jupiter. Asteroids are also known as the minor planets. Basically the word Asteroid means Starlike. Ceres asteroid was the first to be discovered. [B][U][SIZE="4"][COLOR="purple"]Meteorites:[/COLOR][/SIZE][/U][/B] Meteorites are small chunks of iron and rock thought to be resulted from collisions between asteroids. They also may be formed when comets disintegrate into fragments. Meteorites enter the earths atmosphere and become a meteor. A meteor is a falling star that is usually seen in the sky at night. A meteor will burn up from frictional heating as it enters the atmosphere. Most of the meteors burn up before they reach the earth. If they do not reach the ground they become meteorites. Meteorites can be seen at a distance of 70 miles from the earth. Meteorites are heavy objects which weigh about 60 tons. [B][U][SIZE="4"][COLOR="purple"]Comets:[/COLOR][/SIZE][/U][/B] Comets are those bodies which revolve round the sun. they are mainly composed of ice and dust. Most comets have three parts which are as under. i) A solid centre. ii) A head or round coma, that surrounds the centre and consists of dust particles mixed with frozen water, frozen methane and frozen water, frozen methane and frozen ammonia. iii) A long tail of dust and gases that escape from the head. Most comets stay near the solar system. Other characteristics of comets are as under: Comet is usually about 10 km or 6 miles across. Comets are usually made up of ice and dust. Millions of comets are present in the solar system. Halleys comet is the famous example. Comets usually move around the sun in the elliptical orbits. [B][U][SIZE="4"][COLOR="purple"]Light Year:[/COLOR][/SIZE][/U][/B] The distance travelled by light at speed of 186,000 miles per seconds in one year is known as a light year. One light year is approximately 9461,000 million kilometres or 5875000 miles. Light year is also used to measure the distance between the galaxies. [B][U][SIZE="4"][COLOR="purple"]Astronomical Unit:[/COLOR][/SIZE][/U][/B] The distance between the Sun and the Earth is called as Astronomical Unit. This unit is also used in the measurement of distances between the heavenly bodies within the solar system. The earth is one A.U away from the Sun and the Pluto is 39 A.U away from the Earth. [B][U][SIZE="4"][COLOR="purple"]Black hole:[/COLOR][/SIZE][/U][/B] Black Hole is a hypothetical region in space which has a big gravitational pull for which no matter or radiation can escape from it. Even it is believed that light cannot escape from it. Black Hole usually likes at the centre of galaxy. [B][U][SIZE="4"][COLOR="purple"]Super Nova:[/COLOR][/SIZE][/U][/B] A Super Nova is an exploding star. At the end of its phase as a Red Giant, a heavy star explodes as a Supernova shining briefly as brightly as a thousand million stars. Recent Supernova was observed on the night of Feb 23, 1987. This occurred in Large Magellanic Cloud. [B][U][SIZE="4"][COLOR="purple"]Nebula:[/COLOR][/SIZE][/U][/B] Nebula is derived from a Greek word which means Cloud. In the sky there are clouds like objects, which are classified as Nebulae. There are both luminous diffuse nebulae and dark obscuring nebulae over the Milky Way. They are made up of dust and gases. [B][U][SIZE="4"][COLOR="purple"]Aurora:[/COLOR][/SIZE][/U][/B] Aurora or Kutub-i-Raushani is a luminous meteoric phenomenon of electrical character seen in Polar Regions with a tremulous motion and giving forth streams of eight Aurora. It is generally believed that the aurora is actually caused by radiation from the Sun-spots. [B][U][SIZE="4"][COLOR="purple"]Solar Wind:[/COLOR][/SIZE][/U][/B] Solar wind is the stream of electrically charged particles especially protons and electrons, which are emitted by the Sun, predominantly during solar flares and sunspots activity. Some of these particles become trapped in the Earths magnetic field forming the outer Van Allen radiation belt, but some penetrate into the upper atmosphere where they congregate in narrow zones in the region of the Earths magnetic poles producing aurora displays. [B][U][SIZE="4"][COLOR="purple"]Cosmic Rays:[/COLOR][/SIZE][/U][/B] Cosmic Rays are charged particles moving as fast as the speed of light. Most of the particles are protons, while some are alpha particles and electrons. They travel throughout our galaxy, including the solar system and some strike the earths atmosphere. They can be detected by instruments on the Earth. Nobody knows how cosmic rays are formed. Some of them are formed by exploding stars or supernova and some come from outside our Galaxy. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Some Important Definitions:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][SIZE="4"][COLOR="purple"]Cosmology:[/COLOR][/SIZE][/U][/B] Cosmology is the science of the cosmos or universe. [B][U][SIZE="4"]OR[/SIZE][/U][/B] Cosmology is the branch of physical science which deals with the Universe. [B][U][SIZE="4"][COLOR="purple"]Universe:[/COLOR][/SIZE][/U][/B] The universe is the sum total of all that exists, or has existed, both in space and time. [B][U][SIZE="4"][COLOR="purple"]Galaxy:[/COLOR][/SIZE][/U][/B] A galaxy is a system of many thousands of millions of stars together with inter-stellar gas and dust. [B][U][SIZE="4"]OR[/SIZE][/U][/B] Galaxy is a fundamental unit of the universe. It is composed of hundreds of thousands of stars together with intra-stellar gas and dust. [B][U][SIZE="4"][COLOR="purple"]Star:[/COLOR][/SIZE][/U][/B] Those heavenly bodies which are luminous and produce their own energy by nuclear reactions are called stars. Proximal Centauri second nearest after Sun to the Earth. Antares is one of the largest stars known. [B][U][SIZE="4"][COLOR="purple"]Solar system:[/COLOR][/SIZE][/U][/B] A tiny system of our galaxy which consists of the /sun, a planet and their satellites, thousands of miniature planets called asteroids, meteoroids, comets, interplanetary dust and plasma. [B][U][SIZE="4"][COLOR="purple"]Satellite:[/COLOR][/SIZE][/U][/B] Those heavenly bodies which revolve round the planets are called satellites. [B][U][SIZE="4"][COLOR="purple"]Eclipse: [/COLOR][/SIZE][/U][/B] In astronomy, the term eclipse simply means the obscuring of one heavenly body by another, particularly that of the sun or a planetary satellite. [B][U][SIZE="4"][COLOR="purple"]Lunar Eclipse:[/COLOR][/SIZE][/U][/B] A condition when the earth comes in between the sun and the moon and throws its shadow on the moon is called lunar eclipse. [SIZE="4"][COLOR="purple"][B][U][SIZE="4"][/SIZE]Solar Eclipse:[/U][/B][/COLOR][/SIZE] A condition when the moon comes in between the sun and the moon and throws its shadow on the moon is called Solar Eclipse. [B][U][SIZE="4"][COLOR="purple"]Astrology:[/COLOR][/SIZE][/U][/B] Astrology is the interpretation of the influence of planets and stars on human lives. [B][U][SIZE="4"][COLOR="purple"]Asteroids:[/COLOR][/SIZE][/U][/B] Small, irregular shaped rocky objects which orbit the sun between the orbits of Mars and Jupiter are called Asteroids. [B][U][SIZE="4"][COLOR="purple"]Meteorites:[/COLOR][/SIZE][/U][/B] Tiny chunk of material floating in space which can also enter the earths atmosphere and become meteor are known as meteorites. [B][U][SIZE="4"][COLOR="purple"]Comets:[/COLOR][/SIZE][/U][/B] The bodies mainly composed of ice and dust which revolve round the sun are called comets. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Balanced Diet:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
The food which contains all essential food nutrients which are necessary and essential for healthy growth of the body and proper functioning of the whole parts of body. Food is a complex mixture of chemical substances. It performs following useful functions when eaten and absorbed by the body. [B][COLOR="purple"]i) Produces energy ii) Promote growth iii) Repair the tissues iv) Regulate various processes[/COLOR][/B] Nutrients are the chemical components of food capable of performing above functions. Example: milk is a balanced diet although it does not contain iron. Following are the major components of Balanced Diet and their source and functions: [B][U][COLOR="purple"]i) Carbohydrates[/COLOR][/U][/B] [B]Source:[/B] Honey, Sugarcane, Wheat, Maize, Potatoes. [B]Functions:[/B] Provide energy [B][U][COLOR="purple"]ii) Fats: [/COLOR][/U][/B] [B]Source:[/B] Butter, Cheese, Soya bean, Mustard etc. [B]Functions:[/B] Provide Energy [B][U][COLOR="purple"]iii) Proteins: [/COLOR][/U][/B] [B]Source:[/B] Meat, Eggs, Fish, Milk, Pulses etc. [B]Functions:[/B] Essential for growth [B][U][COLOR="purple"]iv) Vitamins: [/COLOR][/U][/B] [B]Source:[/B] Fruits and Vegetables. [B]Functions:[/B] Important for proper physiologic and metabolic functions of the body. [B][U][COLOR="purple"]Types: [/COLOR][/U][/B] a) Water Soluble Vitamins: B1, B2, B6, B12, C b) Fat Soluble vitamins: A, D, E, K v) [B][U][COLOR="purple"]Minerals:[/COLOR][/U][/B] Minerals are those inorganic substances which play a key role in the maintenance and building of the body tissues. The most important minerals of balanced diet are as under: [B]Phosphorus:[/B] is necessary for bones and teeth. [B]Iron:[/B] is an essential component of blood. [B]Iodine:[/B] is necessary for thyroxin which is secreted from thyroid gland. [B]Calcium:[/B] is necessary for bone development. [B][U][COLOR="purple"]vi) Water:[/COLOR][/U][/B] [B]Source: [/B]Fruits, Vegetables [B]Functions:[/B] It is constituent of blood, lymph, hormones and other secretions of the body. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Functions Of Vitamins:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]1. Vitamin A[/COLOR][/U][/B] i) [B]Role: [/B]Vitamin A plays an important role in growth and body repair, keeps the skin smooth and essential for vision. ii) [B]Deficiency:[/B] it deficiency causes Night Blindness. iii) [B]Source: [/B]Fortified milk, butter, eggs, cream, leafy vegetables, carrot. [B][U][COLOR="purple"]2. Vitamin B1[/COLOR][/U][/B] i) [B]Role:[/B] it is an energy building vitamin, help in the digestion of carbohydrates, keep the heart and muscle stable and necessary for nerves. ii) [B]Deficiency:[/B] its deficiency causes Beri Beri, muscular weakness, cramps and heart swelling. iii) [B]Source: [/B]Pork, cereals, legumes, nuts and seeds. [B][U][COLOR="purple"]3. Vitamin B2 (Riboflavin)[/COLOR][/U][/B] i) [B]Role: [/B]It is important in forming RBCs, protection of mouth and mucous membrane and skin. ii) [B]Deficiency: [/B]its deficiency causes Pellagra iii) [B]Source:[/B] Milk, leafy green vegetables, cereals etc. [B][U][COLOR="purple"]4. Vitamin B3 (Niacin)[/COLOR][/U][/B] i) [B]Role:[/B] Helps in releasing energy from carbohydrates, fats and proteins, very essential for the DNA synthesis, used to lower elevated LDL cholesterol and triglyceride levels in the blood, boosts the level of HDL, the 'good' cholesterol, in the body, essential for the proper digestion of the food etc. ii) [B]Deficiency:[/B] its deficiency causes Loss of appetite, Indigestion, Skin lesions, Mental imbalance etc. iii) [B]Source:[/B] Meat, poultry, fish, cereals, vegetables, peanuts, butter etc. [B][U][COLOR="purple"]5. Vitamin B6 (Pyridoxine)[/COLOR][/U][/B] i) [B]Role:[/B] it is essential for the production of antibodies, for the CNS and help in protein metabolism in the body. ii) [B]Deficiency:[/B] Skin problems, Nervous system disorders, Muscle spasms, Sleeplessness. iii) [B]Source:[/B] Meat, fish, poultry, vegetables, fruits etc. [B][U][COLOR="purple"]6. Vitamin B12 (Cynocobalamin)[/COLOR][/U][/B] i) [B]Role:[/B] it is important for carbohydrate and fat metabolism, growth of child and formation of blood. ii) [B]Deficiency:[/B] its deficiency causes anaemia iii) [B]Source:[/B] Meat, poultry, fish, seafood, eggs, milk. [B][U][COLOR="purple"]7. Vitamin C (Ascorbic Acid)[/COLOR][/U][/B] i) [B]Role: [/B]It is essential for protection of bones and for healthy teeth and gums. ii) [B]Deficiency:[/B] its deficiency causes Scurvy iii) [B]Source:[/B] Citrus fruit, guava, pineapple, tomatoes, spinach, turnips, strawberry. [B][U][COLOR="purple"]8. Vitamin D:[/COLOR][/U][/B] i) [B]Role:[/B] It is very important for the growth of children. ii) [B]Deficiency:[/B] Its deficiency causes Rickets in children and Osteoporosis in adults. iii) [B]Source:[/B] Egg yolk, liver, fish, milk. [B][U][COLOR="purple"]9. Vitamin E:[/COLOR][/U][/B] i) [B]Role:[/B] it plays an important role in wound healing, prevention of sterility, breaking blood clots and prevents damage of cells due to aging. ii) [B]Source:[/B] Leafy green vegetables, soya bean, cotton seed, liver, egg yolk, nuts etc. iii) [B]Deficiency:[/B] its deficiency slows down the formation of RBCs. [U][COLOR="Purple"][B]10. Vitamin K:[/B][/COLOR][/U] i) [B]Role:[/B] essential for blood clotting. ii) [B]Deficiency:[/B] its deficiency causes Blood clotting Disorder iii) [B]Source:[/B] Leafy green vegetables, milk, fish, liver, alfalfa. |
[B][U][CENTER][FONT="Georgia"][COLOR="Purple"][SIZE="5"]Minerals: Their Functions, Source and Sings Of Deficiency:[/SIZE][/COLOR][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]1. Calcium: [/COLOR][/U][/B] [B]i) Role:[/B] a) It is essential constituent of bones and teeth. b) It is vital for metabolic process such as nerve function, muscle contraction, and blood clotting. [B]ii) Source: [/B]Dairy Products [B]iii) Deficiency: [/B]Osteomalacia (softening of bones), Osteoporosis, Rickets, Tetany [B][U][COLOR="purple"]2. Iron: [/COLOR][/U][/B] [B]i) Role:[/B] It is the key constituent of haemoglobin which helps in transfer of oxygen. [B]ii) Source:[/B] Eggs, Green Vegetables, Fortified foods, Cereals, White flour, Liver, Meat, Nuts, Peas. [B]iii) Deficiency:[/B] Anaemia, Increased susceptibility to infection. [B][U][COLOR="purple"]3. Magnesium:[/COLOR][/U][/B] [B]i) Role:[/B] it is essential for healthy bones; muscles and nervous tissues. It is needed for functioning of approx. 90 enzymes. [B]ii) Source:[/B] Eggs, leafy vegetables, fish, milk and dairy products. [B]iii) Deficiency:[/B] Anxiety, fatigue, insomnia, muscle problem, nausea, premenstrual problem. [B][U][COLOR="purple"]4. Phosphorus:[/COLOR][/U][/B] [B]i) Role:[/B] it is important for healthy bone tissues. [B]ii) Source:[/B] Dairy products, fruits, meat, pulses, leafy vegetables. [B]iii) Deficiency:[/B] Anaemia, demineralization of bones, nerve disorder, respirator problem, weakness, weight loss. [B][U][COLOR="purple"]5. Potassium:[/COLOR][/U][/B] [B]i) Role:[/B] it is essential for intracellular fluid, maintenance of electrical potential of the nervous system and functioning of muscle and nerve tissues. [B]ii) Source:[/B] Cereals, coffee, fresh fruits, meat, vegetables, whole-grains, flour. [B]iii) Deficiency:[/B] General muscle paralysis and metabolic disorder. [B][U][COLOR="purple"]6. Sodium:[/COLOR][/U][/B] [B]i) Role:[/B] it is necessary for the control of the volume of extra cellular fluid in the body maintenance of pH of the body, and electrical potentials of the nervous system. [B]ii) Source:[/B] Bakery products, Table salts [B]iii) Deficiency:[/B] Low blood pressure, general muscle weakness, respiratory problems. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Computer:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B]The word Computer is derived from compute which means to calculate. In simple and technical term it is an automatic electronic calculating machine that processes or manipulates a given data according to a program or set of instructions and gives a desired output. [/B] [B][U][COLOR="purple"]Parts Of A Computer:[/COLOR][/U][/B] The computer is composed of two parts: 1) Hardware 2) Software [B][U][COLOR="purple"]1) Hardware:[/COLOR][/U][/B] All physical components of computer, which can be touched, measured, have weight and occupy space, are collectively called computer hardware viz; i) Keyboard ii) Mouse iii) Joy stick iv) Scanners v) Monitor vi) Printer vii) Central Processing unit etc. [B][U][COLOR="purple"]2) Software:[/COLOR][/U][/B] Software can be defined as a set of instructions or codes written in a defined manner. In other words softwares are prewritten programs, which control the operations of computer. [B][U][COLOR="purple"]OR[/COLOR][/U][/B][CENTER][/CENTER] All programs and data stored on floppy disk, Hard disk, CD-ROM are collectively called softwares. Examples are; i) DOS ii) Window iii) UNIX iv) XENIX v) Linus vi) Java vii) MS Office [B][U][COLOR="purple"]Devices OR Components Of A Computer:[/COLOR][/U][/B] The computer is a combination of many parts, each of which performs specific task independently. The major devices of a computer are as under. [B][U][COLOR="purple"]1) Input Devices[/COLOR][/U][/B] The input devices are those devices which send data or information to the Central Processing Unit. The main input devices are: [B]i) KEYBORD:[/B] It is used to enter text. It contains alphabetic, numeric and other keys for entering data. [B]ii) MOUSE:[/B]It is a pointing device. It controls the pointer on the screen. [B]iii) MICROPHON:[/B] It is used to enter voice into the computer. [B]iv) SCANNER:[/B] It reads printed text and graphics and then translates the result into digital form. [B]v) DIGITAL CAMERA:[/B]It is used to take photos. [B]vi) PC CAMERA:[/B] It is used to create movie and to take photos on the computer. [B][U][COLOR="purple"]2) OUT PUT DEVICES:[/COLOR][/U][/B] A hardware component used to display information to the user output device. i) [B]MONITER:[/B] It is used to display text, graphics and video output. ii) [B]PRINTER:[/B] It is used to display printed output on paper. iii) [B]SPEAKER:[/B]It is used to hear sound to hear sound music and voice outputs. [B][U][COLOR="purple"]3) STORAGE DEVICE:[/COLOR][/U][/B] The hardware components used to store data, instructions and information permanently are called storage devices. For example floppy disk drive, zip drive, hard disk drive, CD-ROM drives etc. [B][U][COLOR="purple"]4) COMMUNICATION DEVICES:[/COLOR][/U][/B] It is used to communicate and exchange data, instructions and information with other computers. For example Modem. [B][U][COLOR="purple"]UNITS OF CPU:[/COLOR][/U][/B] [B][U][COLOR="purple"]ALU(ARTHMETIC AND LOGICAL UNIT)[/COLOR][/U][/B] ALU is a part of CPU. Actual execution of instructions takes place in this part. All arithmetic and logical operations are performed in ALU. It consists of two units: [U][B]1. Arithmetic Unit[/B][/U] It performs basic arithmetic functions such as addition, subtraction, division. [U][B]2. Logical Unit[/B][/U] It performs logical operations like comparing two data items to find which data item is greater than, equal to, or less than the other. [B][U][COLOR="purple"]CONTROL UNIT[/COLOR][/U][/B] It acts like a supervisor of the computer. It does not execute program instruction by itself. It controls and coordinates all activities of computer system. [B][U][COLOR="purple"]Memory Unit (MU)[/COLOR][/U][/B] It is responsible for storage of data and information. The memory unit consists of two types of memory which are RAM and ROM. [B][U][COLOR="purple"][SIZE="4"]Some Important Definitions And Short Notes:[/SIZE][/COLOR][/U][/B] [B][U][COLOR="purple"]RAM: [/COLOR][/U][/B] RAM stands for random access memory. It is that part of CPU where temporary information is stored. [B][U][COLOR="purple"]Byte:[/COLOR][/U][/B] A group of 8 bits is called a byte. [B][U][COLOR="purple"]Icons:[/COLOR][/U][/B] Pictorial objects on the desktop or screen are called Icons. [B][U][COLOR="purple"]Mouse:[/COLOR][/U][/B] It is an input device, normally called a Pointing device. This device is used for pointing anything on monitor through a blinking cursor. [B][U][COLOR="purple"]Software:[/COLOR][/U][/B] A set of instructions or codes written in a defined manner or prewritten programs which control the operations of computer. [B][U][COLOR="purple"]Control Unit:[/COLOR][/U][/B] A unit of CPU which is responsible for all automatic operations carried out by the digital computers is called CU. The CU directs and coordinates all activities of a computer. [B][U][COLOR="purple"]LAN:[/COLOR][/U][/B] LAN stands for local area network. It is privately owned communication network that serves users within a confirmed geographical area. The range is usually within a mile-perhaps one office, one building or a group of buildings. [B][U][COLOR="purple"]WAN:[/COLOR][/U][/B] It stands for wide area network. It is a communication network that covers a wide geographical area. The range is usually a state or a country. Examples are Telenet, Uninet etc. [B][U][COLOR="purple"]Modem:[/COLOR][/U][/B] Modem is abbreviation of Modulate-de-Modulate. Modulation is a process that converts digital signals into Analog form and Demodulation is a process that converts Analog signals into digital form. The device which performs modulation and demodulation is called a MODEM. In simple words it is a device that converts the digital signals into Analog and then back from Analog to digital form. [B][U][COLOR="purple"]ALU:[/COLOR][/U][/B] A unit of CPU that performs arithmetic and logical operations is called ALU. [B][U][COLOR="purple"]Register:[/COLOR][/U][/B] Registers are high-speed staging areas that temporarily store data during processing and provide working areas for computation. Registers are contained in control unit and arithmetic Logic Unit. Following are the major types of registers: i) Address Register ii) Instructions Register iii) Storage Register iv) Accumulator Register [B][U][COLOR="purple"]Soft Copy:[/COLOR][/U][/B] It displays the data on screen of monitor. It can be carried in a floppy disk. A change can be made in a soft copy. [B][U][COLOR="purple"]Hard Copy:[/COLOR][/U][/B] The data is printed on paper card etc. with the help of printer. It cannot be carried in a floppy disk. No change can be made in hard copy. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Energy:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]Definition Of Energy:[/COLOR][/U][/B] Energy is an agent which is responsible to do work. [B][U][COLOR="purple"]OR[/COLOR][/U][/B] The capacity or ability of doing some work is known as energy. [B][U][COLOR="purple"]Kinds OR Types Of Energy:[/COLOR][/U][/B] [B]i) Kinetic energy:[/B] The energy due to motion of a body is called Kinetic Energy. [B]Example:[/B] i) Moving ball can break a glass window ii) A striking hammer can drive a nail. [B]ii) Potential Energy:[/B] the energy which is possessed by a body by means of its position is known as potential energy. [B]iii) Mechanical Energy: [/B] Energy of an object due to its motion or position [B][U][COLOR="purple"]OR[/COLOR][/U][/B] A combination of kinetic and potential energy resulting from the force of gravity or the movement or release of a machine component, such as a spring, clamp, or wheel. [B]iv) Chemical energy:[/B] energy in a substance that can be released by a chemical reaction. For example: coal, petroleum are the source of chemical energy. [B]v) Electrical energy:[/B] energy made available by the flow of electric charge through a conductor. [B]vi) Heat energy: [/B]a form of energy that is transferred by a difference in temperature. [B]vii) Solar energy: [/B]Radiant energy emitted by the sun. [B]viii) Hydropower energy:[/B] The energy in flowing water is called Hydropower Energy. [B]ix) Nuclear energy:[/B] The energy released by a nuclear reaction, especially by fission or fusion. [B][U][COLOR="purple"]Energy Resources:[/COLOR][/U][/B] Energy resources can be divided into two categories. 1) Renewable Resources Of energy 2) Non-Renewable Resources Of energy [B][U][COLOR="purple"]Renewable Resources Of Energy:[/COLOR][/U][/B] Renewable energy is energy which is generated from natural sources i.e. sun, wind, rain, tides and can be generated again and again as and when required. They are available in plenty and by far most the cleanest sources of energy available on this planet. For e.g.: Energy that we receive from the sun can be used to generate electricity. Similarly, energy from wind, geothermal, biomass from plants, tides can be used this form of energy to another form. [B][U][COLOR="purple"]OR[/COLOR][/U][/B] The resources of energy which can be used again and again are known as renewable resources. These are: [B]i) Solar energy:[/B] Solar energy is the energy derived from the sun through the form of solar radiation. [B]ii) Wind energy: [/B]Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, wind mills... [B]iii) Hydropower energy: [/B]Energy in water can be harnessed and used. Since water is about 800 times denser than air, even a slow flowing stream of water, or moderate sea swell, can yield considerable amounts of energy. [B]iv) Tidal energy: [/B]Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity. [B]v) Geothermal energy: [/B]Geothermal energy is power extracted from heat stored under the earths crust. This power source is generally cost effective, usually reliable, mostly sustainable, and generally environmentally friendly. [B][U][COLOR="purple"]Non-Renewable Resources Of Energy:[/COLOR][/U][/B] Renewable energy is energy which is taken from the sources that are available on the earth in limited quantity and will vanish fifty-sixty years from now. Non-renewable sources are not environmental friendly and can have serious effect on our health. They are called non-renewable because they can be re-generated within a short span of time. Non-renewable sources exist in the form of fossil fuels, natural gas, oil and coal. [B][U][COLOR="purple"]OR[/COLOR][/U][/B] The resources of energy which can be used for a particular period of time, after that they may not be available for the use of man. These include: [B]i) Coal: [/B]Coal is a combustible black or brownish-black sedimentary rock formed from fossilized plants. Coal consists of amorphous carbon with various organic and some inorganic compounds and is normally occurring in rock strata in layers or veins called coal beds. [B]ii) Gas: [/B] Natural gas is a combustible mixture of hydrocarbon gases that occurs with petroleum deposits consisting primarily of methane. It is found with other fossil fuels and in coal beds and is created by the decay of methanogenic organisms in marshes, bogs, and landfills. Lower temperatures are likely to produce more petroleum, and higher temperatures are likely to produce more natural gas. [B]iii) Oil:[/B] Petroleum, also known as crude oil, is a naturally occurring toxic combustible liquid primarily made up of hydrocarbons. Petroleum is the result of partial decay of living organisms occurring in the rock strata of certain geological formations. [B]iv) Nuclear fuels:[/B] Nuclear power is produced by controlled nuclear fission (splitting atoms). In most cases nuclear power plants use nuclear fission reactions to heat water, using the steam to produce electricity. Uranium, specifically, uranium -235, is one of the few elements easily fissioned. [B]v) Wood:[/B] Wood and wood products used as fuel, including round wood (cord wood), limb wood, wood chips, bark, sawdust, forest residues, charcoal, pulp waste, and spent pulping liquor. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Short Notes (Energy)[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][SIZE="4"][COLOR="purple"]Non-Conventional Sources Of Energy:[/COLOR][/SIZE][/U][/B] Non-conventional sources of energy are those sources of energy which are not in common use at this time but are being considered or explored to bring to routine use in the future. With the exhaustion of conventional sources of energy the search for non-conventional sources of energy have been intensified. Conventional sources of energy are coal, gas, oil, wood and nuclear fuels. These sources are in routine use nowadays. Non-conventional sources of energy are solar energy, geothermal energy. Wind energy, tidal energy and ocean thermal gradient. [B][U][SIZE="4"][COLOR="purple"]Solar Energy:[/COLOR][/SIZE][/U][/B] The energy of the sun is called solar energy. It has been estimated that on the average 180,000 kilowatts solar energy is falling per square kilometre of the earth. Solar energy is utilized in two ways. A solar furnace contains thousands of mirrors to focus the sun rays. In this solar heater produces heat used in industry or houses. The heaters heat up water or air. Solar energy can also be used indirectly. Solar cells made up of panels of semi-conductors (usually silicon) are used which when illuminated by sun generate electricity. These kinds of cells have frequently been used in space probe. They have not become popular in domestic side due to high cost. [B][U][SIZE="4"][COLOR="purple"]Wind Energy:[/COLOR][/SIZE][/U][/B] Energy obtained from wind by using wind mills is called wind energy. The wind rotates generated which produce electricity. Previously wind mills were used for grinding grains. The rotating wings of a wind mill can be attached to a magnet which gives an electric current with rotation. Low power, high cost and uncertainties of weather had not made power generation through wind power. [B][U][SIZE="4"][COLOR="purple"]Geothermal energy:[/COLOR][/SIZE][/U][/B] Heat energy obtained from the hot molten metals inside the earth crust serves as the source of thermal energy. This type of energy is present in the form of hot water and steam. Geothermal electricity plants change the geothermal energy into electricity. Hot water of springs is being used for power generation particularly in USA, Italy, and Japan etc. furthermore; hot springs are used as geysers for heating the houses. [B][U][SIZE="4"][COLOR="purple"]Nuclear Energy:[/COLOR][/SIZE][/U][/B] The most concentrated form of energy is in the atomic nuclei. This energy can be released by the processes of fission or fusion. Fusion reactions have been producing electricity in commercial quantities for about 30 years. In Pakistan we have got only one fission nuclear reactor located at Karachi which generates 137 megawatt of power to meet ur future domestic and industrial needs, we will have to generate electricity from nuclear plants using (Uranium U-235) and plutonium s fuel. [B][U][SIZE="4"][COLOR="purple"]Tidal Energy:[/COLOR][/SIZE][/U][/B] Energy which is obtained through the tidal waves of the sea is called tidal energy. Tidal waves of sea strike the shore constantly. These waves are used to run electric generators which produce electricity. The kinetic energy of the tides is also used to produce other forms of mechanical work. Tidal power station traps high tides behind a barrage. The water flows through turbines. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Greenhouse Effect:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
The heating that occurs when gases such as carbon dioxide trap heat escaping from the Earth and radiate it back to the surface; so-called because the gases are transparent to sunlight but not to heat and thus act like the glass in a greenhouse. [B][U][COLOR="purple"]OR[/COLOR][/U][/B] The overall warming of the earth's lower atmosphere primarily due to carbon dioxide and water vapour which permit the sun's rays to heat the earth, but then restrict some heat-energy from escaping back into space. [B][U][COLOR="purple"][SIZE="4"]Greenhouse Gases:[/SIZE][/COLOR][/U][/B] i) Carbon dioxide CO2 ii) Methane iii) Water Vapour iv) Chloro Fluoro-Carbon (CFC) v) Nitrous oxide [B][U][COLOR="purple"][SIZE="4"]Mechanism OF Greenhouse Effects:[/SIZE][/COLOR][/U][/B] Our Earth receives most of its energy, called radiation, from the Sun. This energy is electromagnetic radiation in the form of Visible light, with small amounts of Infrared (IR) and Ultraviolet (UV). The incoming Visible solar energy has a very short wavelength and passes right through the atmosphere. The Earth's surface absorbs the solar energy and releases it back to the atmosphere as Infrared (IR) radiation, some of which goes right back into space. But some of the IR radiation emitted by the Earth is absorbed by greenhouse gases in the atmosphere and sent back towards the Earth's surface. That warms the Earth's surface. Three main gases in our atmosphere that contribute to the greenhouse effect are carbon dioxide, methane, and water. These gases absorb the infrared radiation emitted by the Earth and re-radiate the energy as heat back towards the Earth, causing a warming known as the greenhouse effect. The warming due to greenhouse gases is expected to increase as humans add more greenhouse gases to the atmosphere. [B][U][COLOR="purple"][SIZE="4"]Sources Of Greenhouse Gases:[/SIZE][/COLOR][/U][/B] [B]Carbon dioxide (CO2)[/B] is a colourless gas that's a by-product of the combustion of organic matter. Today human activities are pumping huge amounts of CO2 into the atmosphere, resulting in an overall increase in carbon dioxide concentrations. [B]Methane[/B] occurs naturally when organic material decomposes. Man-made processes produce methane in several ways: By extracting it from coal From large herds of livestock (i.e., digestive gases) From the bacteria in rice paddies Decomposition of garbage in landfills [B][U][SIZE="4"][COLOR="purple"]Importance Of Greenhouse Effect:[/COLOR][/SIZE][/U][/B] Following is the importance of greenhouse effect. i) Without greenhouse effect, the Earth would not be warm enough for humans to live. ii) Without greenhouse gases, heat would escape back into space and Earths average temperature would be about 600 F colder. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Global Warming:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants [B][U][SIZE="4"][COLOR="purple"]Causes Of Global Warming:[/COLOR][/SIZE][/U][/B] The main causes of global warming, in order of the magnitude of their impact, are: [B]1. Carbon Dioxide from:[/B] A. Fossil Fuel B. Deforestation C. Failing Sinks [B]2. Methane from:[/B] A. Cattle and Rice Paddies B. the Arctic Tundra C. Clathrates [B]3.[/B] [B]Nitrogen Oxides from Farming 4. Other Gases [/B] [B][U][SIZE="4"][COLOR="purple"]Effects OF Global Warming:[/COLOR][/SIZE][/U][/B] When it comes to global warming, harmful effects like melting polar ice caps, weather changes, and an increase in diseases are changing the world and will ultimately affect your life. Below is the list of effects that global warming is having on environment, climate and human kind. [B]1. Melting of glaciers:[/B] The melting of glaciers will create plethora of problems for human kind and the animals living in the earth. Due to increased global warming, the level of the sea will rise which will lead to flooding and this will in turn create havoc in human life. Apart from raising the sea levels, it will also endanger several species of animals and thus will hamper the balance of the ecosystem. Moreover these large glaciers reflect light back into the space and with meltdown of these glaciers, earth will be further warmed. [B]2. Climate Change:[/B] Irregular weather patterns have already started showing results. Increased precipitation in the form of rain has already been noticed in polar and sub Polar Regions. More global warming will lead to more evaporation which will cause more rains. Animals and plants cannot easily adapt to increase rainfall. Plants may die due to it and animals may migrate to other areas, which can cause entire ecosystem out of balance. [B]3. Droughts:[/B] Large scale evaporation will be the major cause of droughts in many places particularly Africa. Although, it is reeling under the huge pressure of water crisis, increased global warming would further make the situation worse and will cause malnutrition. [B]4. Diseases:[/B] As the temperature becomes warmer, it will have an effect on the health of humans and the diseases they are exposed to. With the increase in the rainfall, water borne diseases are likely to spread specially malaria. The earth will become warmer and as a result heat waves are likely to increase that will cause a major blow to the people particularly in Europe. [B]5. Hurricanes frequency:[/B] As the temperature of the oceans rises, hurricanes and other storms are likely to become stronger. With the increase in the global warming the water in the ocean warms up and it heats up the surrounding air, creating hurricanes. More water evaporation means more hurricanes. [B]6. Agriculture:[/B] Global warming will affect agriculture. Although the results are not visible yet, but it may show its colours in years to come. As the global temperature will increase plants will find it harder to survive and will die. Plants are the major source of food for human beings and as a result food shortage will occur. The shortage of the food may lead to war and conflicts in some countries. [B][U][SIZE="4"][COLOR="purple"]Steps To Control Global Warming:[/COLOR][/SIZE][/U][/B] i) Use Public Transport: ii) Use Renewable Energy Like Wind Power: iii) Burn Methane: iv) Use Smart Cooler, Heater & Air Conditioner v) Tune up and maintain vehicles properly vi) Reduce electricity usage to the maximum vii) Prefer recycling |
[B][U][FONT="Georgia"][CENTER][SIZE="5"][COLOR="Purple"]Ozone Depletion:[/COLOR][/SIZE][/CENTER][/FONT][/U][/B]
[B][U][COLOR="purple"][SIZE="4"]Ozone:[/SIZE][/COLOR][/U][/B] Ozone is a highly reactive and unstable gas, which is formed by the recombination of oxygen (O2) atoms in the presence of intense radiation. Its symbol is O3. [B][U][SIZE="4"][COLOR="purple"]Ozone Layer:[/COLOR][/SIZE][/U][/B] The ozone layer is a naturally occurring zone found in the stratosphere, situated between 10-15 kms above the surface of the Earth. The main function of the ozone layer is to act as a shield against ultraviolet (UV) radiations from the Sun because these rays are harmful to life. [B][U][SIZE="4"][COLOR="purple"]Ozone Depletion:[/COLOR][/SIZE][/U][/B] Destruction of the stratospheric ozone layer which shields the earth from ultraviolet radiation harmful to life. ... [B][U][SIZE="4"][COLOR="purple"]Causes Of Ozone Layer Depletion:[/COLOR][/SIZE][/U][/B] [B]The Main Ozone-Depleting Substances (ODS)[/B] Chlorofluorocarbons (CFCs) The most widely used ODS, accounting for over 80% of total stratospheric ozone depletion. Used as coolants in refrigerators, freezers and air conditioners in buildings and cars manufactured before 1995. Found in industrial solvents, dry-cleaning agents and hospital sterilants. Also used in foam products such as soft-foam padding (e.g. cushions and mattresses) and rigid foam (e.g. home insulation). Halons Used in some fire extinguishers, in cases where materials and equipment would be destroyed by water or other fire extinguisher chemicals. In B.C., halons cause greater damage to the ozone layer than do CFCs from automobile air conditioners. Methyl Chloroform Used mainly in industry for vapour degreasing, some aerosols, cold cleaning, adhesives and chemical processing. Carbon Tetrachloride Used in solvents and some fire extinguishers. Hydro fluorocarbons (HCFCs) HCFCs have become major, transitional substitutes for CFCs. They are much less harmful to stratospheric ozone than CFCs are. But HCFCs they still cause some ozone destruction and are potent greenhouse gases. [B][U][COLOR="purple"][SIZE="4"][CENTER]OR[/CENTER][/SIZE][/COLOR][/U][/B] The cause of ozone depletion is the increase in the level of free radicals such as hydroxyl radicals, nitric oxide radicals and atomic chlorine and bromine. The most important compound, which accounts for almost 80% of the total depletion of ozone in the stratosphere are chlorofluorocarbons (CFC). These compounds are very stable in the lower atmosphere of the Earth, but in the stratosphere, they break down to release a free chlorine atom due to ultraviolet radiation. A free chlorine atom reacts with an ozone molecule (O3) and forms chlorine monoxide (ClO) and a molecule of oxygen. Now chlorine monoxide reacts with an ozone molecule to form a chlorine atom and two molecules of oxygen. The free chlorine molecule again reacts with ozone to form chlorine monoxide. The process continues and the result is the reduction or depletion of ozone in the stratosphere. [B][U][SIZE="4"][COLOR="purple"]Effects Of Ozone Depletion[/COLOR][/SIZE][/U][/B] Following are the major effects of ozone layer depletion. i) It will increase the risk of skin cancer ii) It has resulted in melanomas, a kind of tumour. iii) It greatly affects eyes and produces disease of vision. iv) It suppresses immunity system of human beings. v) UV rays damage various crops. vi) It kills plankton and fish larvae. vii) It causes sunburn in human beings. viii) It causes spotting of leaves in plants and trees, thus decreases productivity of the plants. |
[B][U][CENTER][SIZE="5"][FONT="Georgia"][COLOR="Purple"]Acid Rain:[/COLOR][/FONT][/SIZE][/CENTER][/U][/B]
The rainwater which contains a large amount of poisonous acids like sulphuric acid, sulphurous acid, nitrous acid and other pollutants is known as the Acid Rain. [COLOR="Purple"][B][U][SIZE="4"]Formation of Acid Rain[/SIZE][/U][/B][/COLOR] Acid rain is caused by a chemical reaction that begins when compounds like sulphur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain. Sulphur dioxide and nitrogen oxides dissolve very easily in water and can be carried very far by the wind. As a result, the two compounds can travel long distances where they become part of the rain, sleet, snow, and fog that we experience on certain days. [B][U][SIZE="4"][COLOR="purple"]Causes Of Acid Rain:[/COLOR][/SIZE][/U][/B] Human activities are the main cause of acid rain. Over the past few decades, humans have released so many different chemicals into the air that they have changed the mix of gases in the atmosphere. Power plants release the majority of sulphur dioxide and much of the nitrogen oxides when they burn fossil fuels, such as coal, to produce electricity. In addition, the exhaust from cars, trucks, and buses releases nitrogen oxides and sulphur dioxide into the air. These pollutants cause acid rain. [B][U][CENTER][SIZE="4"][COLOR="purple"]OR[/COLOR][/SIZE][/CENTER][/U][/B] The main causes of acid rain are [B][U]Natural Sources:[/U][/B] Lightning strikes (cause nitrogen molecules to be oxidized) Combustion of hydrogen sulphide (hydrogen sulphide is formed from the breakdown of sulphates in organic matter in the absence of oxygen- anaerobic conditions). This reaction forms sulphur dioxide. [B][U]Human Sources:[/U][/B] Combustion engines (car, airplanes etc.) Burning of fossil fuels and coal Some mineral ores contain sulphur dioxide, and this is released when the minerals are processed. [B][U][SIZE="4"][COLOR="purple"]Effect Of Acid Rain:[/COLOR][/SIZE][/U][/B] i) Kills flora and fauna ii) Damages the buildings iii) Causes skin cancer iv) Increases the acidity of the soil v) Kills fish and other aquatic animals vi) Pollutes the water vii) Causes spotting of leaves viii) Causes corrosion of metal, painted surfaces and even stone buildings and monuments. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Environmental Pollution:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
Destabilization of the balance of the atmospheric composition. [B][U][COLOR="purple"][CENTER]OR[/CENTER][/COLOR][/U][/B] It is an unstable change in the composition of the environment due to its physical, chemical and biological changes, which is harmful for human life and other animals living on the earth. [B][U][COLOR="purple"]Types Of Pollution:[/COLOR][/U][/B] i) Air pollution ii) Water pollution iii) Land pollution iv) Noise pollution v) Industrial pollution vi) Commercial or domestic sector pollution vii) Chemical pollution viii) Radioactive pollution (contamination) [B][U][COLOR="purple"]Causes of Pollution[/COLOR][/U][/B] The ultimate cause of pollution is human activity itself. Pollution is a human contribution to nature. Science has evolved technologies and technologies have helped the human welfare. In the process, the pollution has been a part of technology and therefore a part of human miseries. [B]Human activities mainly include:[/B] Industries for various human needs - directly and indirectly Agriculture for food production and industrial needs Health care for health of human beings and animals Transport for mobility of human beings Dwelling for settlement in city or villages Energy for various direct human needs and industrial needs. [B][U][COLOR="purple"]Pollutants:[/COLOR][/U][/B] Pollutants are those substances which alter the natural composition of the atmosphere or destroy it to harmful level. [B][U][COLOR="purple"]Types Of Pollutants:[/COLOR][/U][/B] [B]1. Primary Pollutants[/B] Primary pollutants are those substances which are directly produced by a process. These are: ix) Sulphur oxides x) Nitrogen oxides xi) Carbon monoxide (CO) xii) Carbon dioxide xiii) Volatile organic compounds (VOC), such as hydrocarbon fuel vapours and solvents xiv) Particulate matter (PM), such as smoke and dust. xv) Metal oxides, especially those of lead. xvi) Chlorofluorocarbons (CFCs) xvii) Ammonia (NH3) xviii) Garbage, sewage and industrial wastes. [B][U]2. Secondary Pollutants[/U][/B] Secondary pollutants are those pollutants which are not emitted. Rather, they form in the air when primary pollutants react or interact. [B]These are:[/B] i) Ground level ozone (O3) ii) Nitrogen dioxide iii) Peroxyacetyl nitrate (PAN) [B][U][COLOR="purple"]Effects Of Pollution:[/COLOR][/U][/B] [B]1) Air Pollution:[/B] Irritation of eyes, nose, mouth and throat, Increased respiratory disease, Cancer, Reduced lung functioning, Premature death. Acid rain, Ozone, [B]2) Water Pollution:[/B] Waterborne diseases such as; Typhoid, Hepatitis, diarrhoea, vomiting, and stomach aches, death of aquatic animals, May disrupt photosynthesis in aquatic plants [B]3) Soil Pollution:[/B] Causes cancers including leukaemia, developmental damage to the brain, kidney damage; depression of the central nervous system, Also causes headaches, nausea, fatigue, eye irritation and skin rash, Contamination of crops, reduce crop yields. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Water Pollution:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]Definition:[/COLOR][/U][/B] The presence of undesirable substances into fresh and natural water which cause harmful diseases in human beings as well as aquatic life is called water pollution. [B][U][COLOR="purple"]Types Of Water Pollution:[/COLOR][/U][/B] Following are the major types of water pollution. i) Sea-water Pollution ii) River water Pollution iii) Land Water Pollution [B][U][COLOR="purple"]Causes Of Water Pollution:[/COLOR][/U][/B] [B]1) Pollution Through Domestic Activities:[/B] Domestic activities pollute the water when following kinds of wastes are added. i) Soap and detergents ii) Chemicals used in the houses iii) Waste from slaughter house iv) Waste from hospitals v) Waste from bakeries vi) Human and animal faeces vii) Waste food [B]2) Pollution Through Industrial Activities:[/B] Industrial sector is a great source of pollution of water and air. Many industrial units produce waste materials in the shape of solids, liquids and gases. The industrial wastes are. i) Poisonous gases ii) Acids, bases and harmful salts iii) Pesticides and plastics iv) Radioactive wastes v) Toxic wastes from fertilizer factories vi) Wastes from chemical factories [B][U][COLOR="purple"]Water Pollution In Pakistan: [/COLOR][/U][/B]In Pakistan people do not take pain to dispose the waste materials in a proper way. Instead of dumping wastes in the drums and places meant for them they freely throw these into the water drains. Water pollution is very prominent and widespread as a result of urban and industrial activity. Sewage waste from cities and industrial waste are the main factors of water pollution. Many other kinds of wastes which pollute water are from agricultural lands which contain pesticides, waste foods, fertilizers and animal excreta. Wastes from power plants contain radioactive materials, hot water and minerals which also pollute the water. Soaps, detergents, human excreta, animal faeces, wastes from slaughter houses, disease causing micro-organisms from patients and chemicals etc. are drained into water which causes massive water pollution. [B][U][COLOR="purple"]Two Important Industries Of Pakistan Causing Water Pollution:[/COLOR][/U][/B] 1) One of the biggest sources of water pollution is the tanning and leather industry. The industry uses toxic chromium metal and many other toxic substances/chemicals. These toxins are released in natural waters. Effluent of this industry has polluted ground water and water of nearby rivers. This industry is frequent in Kasur and Sialkot area. 2) Pesticide industry in Kala Shah Kaku near Lahore releases huge quantity of acids, pesticides and other dangerous wastes. These wastes are getting entry into a stream flowing nearby. The water of the stream is dangerously polluted. This water ultimately goes to the rivers. [B][U][COLOR="purple"]Effects:[/COLOR][/U][/B] i) Bacteria, viruses, protozoa and worms are carried in polluted water. The diseases caused by them are as under: a) Bacteria: Typhoid, cholera, Dysentery, enteritis. b) Viruses: Hepatitis, Polio, Viral enteritis. c) Protozoa: Amoebic dysentery, diarrhoea. d) Parasitic worms: Schistostomiasis ii) It causes death of aquatic animals. iii) It decreases the fertility of the soil and results in low production. [B][U][COLOR="purple"]Methods To Control Water Pollution:[/COLOR][/U][/B] Different methods can be used to control water pollution. i) The whole sewage waste should be dumped after any treatment. ii) Sewage treatment plants should be installed in cities. iii) The sewage waste must not be drained in river to save water from pollution. iv) Industrial waste should be treated before reaching natural water. v) Industries should be established away from cities and rivers. vi) Nuclear dumping in oceans should be banned. vii) Modern scientific methods should be used in agriculture. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Deforestation:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
It is the process of destruction of the forests. [B][U][COLOR="purple"]Causes Of Deforestation:[/COLOR][/U][/B] A number of agents are responsible for removal of forests. These are fires. Droughts or animals. The principle agent of deforestation is man himself. Humans are cutting forests to colonize the forest areas or to prepare more agricultural lands or for getting food. [B][U][COLOR="purple"]Effects Of Deforestation:[/COLOR][/U][/B] i) Deforestation has many bad effects on human life. With destruction of the forest the process of cleaning of air and production of oxygen is badly affected. ii) Forests are major agents of evaporation and rainfall. With deforestation rainfall is decreased. iii) With cutting of forests, pollution is increasing as the hazardous gases are not completely absorbed by plants. iv) With deforestation carbon dioxide is increasing which is causing global warming. v) With reduction in area of forest, soil erosion is taking place resulting in floods which destroy crops and human life. vi) Deforestation has badly damaged wild life and reduced recreation sites. |
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[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Earth:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]Features Of Earth:[/COLOR][/U][/B] i) The earth is the fifth largest planet of the solar system, where life exists. ii) Its equatorial diameter is 7,927 miles. iii) Its polar diameter is 7900 miles. iv) The earth has average density of 5 ½ g/cc. v) the rotation period of the earth is 23 hours, 56 minutes and 4 seconds. vi) the revolution period of the earth is 365 days. vii) The total mass of the earth is 6*1021 tons. viii) The earth is composed of shells or layers, which are, the crust, mantle and core. ix) It is surrounded by a blanket of gases, which is known as the atmosphere, mainly composed of Nitrogen and Oxygen. x) The surface of the earth is rich in oxygen, silicon, iron, magnesium, sodium etc. [B][U][COLOR="purple"]Structure Of The Earth:[/COLOR][/U][/B] The earth comprises of the following layers: a) The crust b) Moho discontinuity c) The mantle d) The Core [B][U][COLOR="purple"]a) The Crust:[/COLOR][/U][/B] i) It is the outermost layer of the earth. ii) It extends to about 25 miles (40kms) and comprises of rocks. iii) The crust is divided into the oceanic and the continental crust. iv) Out of these the oceanic crust is 808 meter thick and consists of sedimentary mud. v) The continental crust is divided into upper continental and lower continental crust. [B][U][COLOR="purple"]b) Moho discontinuity:[/COLOR][/U][/B] i) The sharp boundary between the crust and mantle is called Moho Discontinuity. [B][U][COLOR="purple"]c) The Mantle:[/COLOR][/U][/B] i) The layer of the earth lying below the crust and above the core is known as the mantle. ii) It is almost 2900 kms (1800 miles) thick and comprises about 80% of the volume of the earth. iii) The chemical composition of the entire mantle is fairly homogenous. iv) However, temperature and pressure increases with depth. v) The behaviour of the earthquake waves as they travel through the mantle further tells us that it consists of several layers and they are: a) Lithosphere b) Asthenosphere c) Mesosphere [B][U][COLOR="purple"]d) The Core:[/COLOR][/U][/B] i) The innermost part of the earth is known as the core. ii) It extends from the base of the mantle to the centre of the earth. vi) This portion consists of melted iron and nickel that is why it is known as Nife. vii) The density of this molten mass of the core is 345 pounds per cubic feet. [B][U][COLOR="purple"]Types Of Movements Of Earth:[/COLOR][/U][/B] There are two types of motions of the earth. One is around its own axis which is called Rotation. One rotation completes in 23 hours, 56 minutes and 4 seconds. The other motion of earth is round the sun, and is called revolution of the earth. One revolution completes in 365 days. Northern end of the earths axis is called the North Pole and the Southern end is called South Pole. An imaginary line drawn round the earth midway between the poles is called equator. The path which the earth takes round the sun is called earths orbit. [B][U][COLOR="purple"]Effects Of These Movements:[/COLOR][/U][/B] Rotation of earth round its axis cause days and nights. That portion of earth, which is within the circle of illumination caused by the rays of sun, has its day. The other side earth, which is away from sun, remains dark and therefore has its night. [B][U][COLOR="purple"]Longer And Shorter Days:[/COLOR][/U][/B] The circular areas near the North and South Pole of the Earth are called Arctic and Antarctic circles, respectively. These are situated at 66 ½0 North and 66 ½0 South of the equator, respectively and form limits of polar region. On June, the earth is in position A. north pole is inclined towards the sun and south pole is away from it. Obviously any place in Northern Hemisphere will have longer days because it remains in light for more than half the time of earths rotation. Places on equator remains in light for half the time making days and nights equal in this region. The southern hemisphere remains in light for less time than half the rotation of earth so the days are shorter here. Positions of days and nights in the northern and southern hemisphere are reversed on 22nd December, when the earth completes its half revolution around the sun, so days are longer in southern hemisphere than those in the north. [B][U][COLOR="purple"]Change Of Season:[/COLOR][/U][/B] The second type of motion of earth is round the sun and is called revolution of the earth. This is the cause of change of seasons. On June 21, the earth is in position A, when the north pole is inclined towards sun while the south pole is away from it. As the sun rays fall vertically and for a longer period in the northern hemisphere, it is summer here but in the southern hemisphere it is winter. On December 22, when the earth completes half revolution, the conditions become reversed; it is summer in the southern hemisphere and winter in the northern hemisphere. |
[B][U][CENTER][FONT="Georgia"][COLOR="Purple"][SIZE="5"]Atmosphere:[/SIZE][/COLOR][/FONT][/CENTER][/U][/B]
The layer of the gases which surrounds the earth is known as the atmosphere. [B][U][COLOR="purple"]OR[/COLOR][/U][/B] The atmosphere is a thin layer of the gases held to the earth by the gravitational attraction. [B][U][COLOR="purple"]OR[/COLOR][/U][/B] Atmosphere is the huge blanket of gas that circles the entire earth. [B][U][COLOR="purple"]Composition Of The Atmosphere:[/COLOR][/U][/B] The atmosphere consists of: i) Nitrogen: 78.03% ii) Oxygen: 20.99% iii) Argon: 0.94% iv) CO2: 0.03% v) Hydrogen: 0.01% vi) Neon: 0.0018% vii) Helium: 0.0005% viii) Krypton: 0.0001% ix) Ozone: 0.000001% [B][U][COLOR="purple"]Layers Of The Atmosphere:[/COLOR][/U][/B] The atmosphere of the earth is divided into following layers. i) Troposphere ii) Stratosphere iii) Ionosphere iv) Exosphere Ionosphere is sub-divided into: i) Mesosphere ii) Thermosphere [B][U][COLOR="purple"]1) Troposphere:[/COLOR][/U][/B] i) Troposphere is the lowest layer of the atmosphere. ii) It extends roughly to a height of 8 kms near the poles and 16-18 kms at the equator. iii) It is troposphere where the people, plants, animals and insects live. iv) It is the layer where all weather occurs thats why it is also referred as The weather Zone. v) In the Troposphere temperature gradually falls with increasing altitude. vi) There is a thin buffer zone between the troposphere and stratosphere is called tropopause. [B][U][COLOR="purple"]2) Stratosphere And Ozone Layer:[/COLOR][/U][/B] i) The second layer of the atmosphere is known as the stratosphere. ii) The stratosphere extends from the tropopause to about 30-31 mile above ground level. iii) The important ozone layer is found in this region where heat is generated by absorption of UV. iv) Here the temperature either remains constant or increases with altitude. [B][U][COLOR="purple"]Stratopause:[/COLOR][/U][/B] It is the upper boundary of the stratosphere which occurs beyond 52 kms. Here the temperature remains constant with increase in height. [B][U][COLOR="purple"]3) Ionosphere:[/COLOR][/U][/B] i) The third major layer of the atmosphere is the ionosphere. ii) It lies above the stratosphere. iii) It lies between about 30 and 90 miles above the surface of the earth. iv) It is divided into mesosphere and thermosphere. v) The ionosphere is bombarded by cosmic radiation and solar x-rays, which causes the gases in the ionosphere to ionize. vi) Brilliant displays of colored lights in the sky called Aurora Borealis in the northern hemisphere and the Aurora Auralis in the southern hemisphere occur when streams of electrically charged particles from the sun (solar wind) ionize the atmosphere gases. [B][U][COLOR="purple"]4) Exosphere:[/COLOR][/U][/B] i) The uppermost layer of the atmosphere extending beyond Ionosphere is called exosphere. ii) Beyond 300 miles is the very rare field exosphere which consists only of scattered atmosphere of O, H and He. |
[SIZE="5"][B][U][CENTER][SIZE="5"][FONT="Georgia"][COLOR="Purple"]Latitude:[/COLOR][/FONT][/SIZE][/CENTER][/U][/B][/SIZE]
[B][U][COLOR="purple"]Definition:[/COLOR][/U][/B] It is the distance on the surface of the earth measured in degrees north and south of the equator. The equator is at zero degree where the poles are at 90 degree. The latitude of the north pole is 900 North and that of south pole is 900 South. [B][U][COLOR="purple"]Characteristics OF Lines Of Latitudes:[/COLOR][/U][/B] i) All lines of latitudes are parallel to the equator as well as parallel to one another. ii) Parallels in the north of the equator are north latitudes while those in the south of equator are known as south latitudes. iii) They are drawn on the globe as circles running in east to west direction. iv) The length of the equator is the maxim um and it goes on reducing till the pole is only a point. [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Longitude[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] [B][U][COLOR="purple"]Definition:[/COLOR][/U][/B] The distance on the earths surface measures in degrees east and west of a line joining the geographical north and south poles and passing through Greenwich in England. Greenwich is at zero degrees longitude. The sun rays have highest altitude simultaneously on all the places at a particular line of longitude as a result of which these are also called as Meridians (Meridian is a Latin word which means Mid-way). Among the latitude, equator is the longest and is taken as reference line. But all the lines of longitude are of the same length and selecting a longitude as lines of reference is a serious problem. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Earthquake:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
Earthquakes are those movements of the earth crust which make the ground vibrated and shake backwards and forwards or in simple words an earthquake is trembling in the earth. The shocks waves are generated at a point within the crust called the focus, and the point on the earths surface vertically above the focus is called the epicentre of the earthquake. The shock waves travel in all directions from the focus. On the earths surface, the shaking is the strongest near the epicentre. These waves are detected by seismograph. [B][U][COLOR="purple"]Occurrence Of Earthquake:[/COLOR][/U][/B] i) Earthquakes occur when rocks subjected to great stress suddenly break, releasing the accumulated energy, which shakes the ground. Vibrations spread out from the epicentre like ripples in water. ii) It may also be caused by movements of the plates, resulting from convection currents in the hot mantle of the earth. iii) Earthquakes are also associated with volcanic activity-eruption of magma. Collapse of mines can also produce small earthquakes. [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="purple"]Volcanoes:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] An opening in the earth's crust through which molten lava, ash, and gases are ejected. [B][U][COLOR="purple"]Occurrence Of Volcanoes:[/COLOR][/U][/B] i) Rocks below the Earth have a very high temperature. ii) The great pressure upon these keeps them in a semi-solid state. iii) If the pressure weakens, then some of rocks become liquid. iv) This liquid is called magma. v) The magma forces its way into cracks of the crust and may either reach the surface of the earth where it forms lava and flow out. [B][U][COLOR="purple"]Types Of Volcanoes On The Basis Of Activity:[/COLOR][/U][/B] There are three types of volcanoes on the basis of volcanic activity, which are as under. [B][U][COLOR="purple"]i) Active Volcanoes:[/COLOR][/U][/B] Volcanoes are said to be active when they frequently erupt or at least when they have erupted within recent time. [B][U][COLOR="purple"]ii) Dormant Volcanoes:[/COLOR][/U][/B] The volcanoes that have been known to erupt and show signs of possible eruption in the future are describes as dormant volcanoes. [B][U][COLOR="purple"]iii) Extinct Volcanoes:[/COLOR][/U][/B] The volcanoes that have not erupted at all in historic times but retain the features of volcanoes are termed as extinct volcanoes. [B][U][COLOR="purple"]Causes of The volcanoes Eruptions:[/COLOR][/U][/B] i) Seafloor spreading ii) Convergence of lithospheric plates iii) Percolation of cold water iv) Orogenic Movements v) High temperature in the interior of the Earth |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Rocks: [/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"][SIZE="4"]Igneous Rocks:[/SIZE][/COLOR][/U][/B] The word igneous means the fires and the rocks formed by solidification of molten rock material known as magma are known as igneous rocks. The first minerals to crystalize out of the melt are high-temperature minerals-the olivines and pyroxenes, which are silicates of magnesium and iron. They tend to be denser than magma and so they sink, leaving the remaining fluid deficient in magnesium and iron. The next group of minerals to solidify are the feldspars (silicates minerals of potassium, sodium, calcium and aluminium); the magma thus loses its metallic constituents first. Finally, any remaining silica crystalizes out as quartz. The entire solidification process therefore results in dense iron-and magnesium-rich rocks and less dense silica rich rocks from the same original fluid. In this way, different types of rocks can be seen in the same rock mass. The most important igneous rocks are: a) Granite rocks b) Gabboro rocks c) Basalt rocks [B][U][COLOR="purple"][SIZE="4"]Sedimentary Rocks:[/SIZE][/COLOR][/U][/B] Sedimentary rocks are formed from the deposition and compaction or lithification of rocks and mineral grains derived from other rocks. These grains broke away from existing rocks by the action of water, wind and ice. Many sedimentary rocks begin their existence as loose deposits of sand or gravel at the bottom of a sea or lake, on beach, or in a desert. Later the sediment is lithified i.e. compressed into a rock. Following are the major classes of sedimentary rocks: i) Calcareous sedimentary rocks ii) Carbonaceous sedimentary rocks iii) Siliceous sedimentary rocks iv) Ferruginous sedimentary rocks v) Arenaceous sedimentary rocks vi) Argillaceous sedimentary rocks vii) Rudaceous sedimentary rocks [B][U][SIZE="4"][COLOR="purple"]Metamorphic Rocks:[/COLOR][/SIZE][/U][/B] The word metamorphic has been derived from two Greek words Meta means change and Morpha means shape. Thus metamorphic rocks include those rocks that have been changed either in form or composition without disintegration. Metamorphic rocks are formed from igneous as well as sedimentary rocks but are different from them. [B][U][COLOR="purple"]Example:[/COLOR][/U][/B] i) Sandstone, made of quartz grains and silica cement, becomes quartzite, a very hard metaphoric rock that resist weathering. ii) Limestone is converted into much denser and harder marble. iii) Mica, an igneous rock, is converted into schist after metamorphosis. iv) Sedimentary rock slate is converted into a slightly higher grade metamorphic rock phyllite. |
[COLOR="Purple"][B][U][CENTER][FONT="Georgia"][SIZE="5"]Branches Of Biology:[/SIZE][/FONT][/CENTER][/U][/B]
[/COLOR] [B][COLOR="Purple"]i) Zoology: [/COLOR][/B]Zoology is that branch of biology which deals with the study of animals. [B][COLOR="purple"]ii) Botany:[/COLOR][/B] Botany is that branch of biology which deals with the study of plants. [COLOR="purple"][B]iii) Microbiology:[/B][/COLOR] It is the branch of biology which deals with the study of microorganisms such as viruses, bacteria etc. [B][COLOR="purple"]iv) Morphology:[/COLOR][/B] It deals with the shape and structure of living organisms. [B][COLOR="purple"]v) Histology:[/COLOR][/B] It is the microscopic study of tissues of plants and animals. [B][COLOR="purple"]vi) Cytology:[/COLOR][/B] It deals with the structure of cell and organelles present inside the cell. [B][COLOR="purple"]vii) Physiology:[/COLOR][/B] It deals with the study of functions of different parts of plants and animals. [B][COLOR="purple"]viii) Ecology:[/COLOR][/B] It is the science of ecosystem and explains the relationship between organisms and their environment. [B][COLOR="purple"]ix) Taxonomy:[/COLOR][/B] It deals with the naming and classification of organisms. [B][COLOR="purple"]x) Genetics:[/COLOR][/B] It deals with the study of heredity and variations. [B][COLOR="purple"]xi) Biotechnology: [/COLOR][/B]It deals with the application of biological processes. [B][COLOR="purple"]xii) Haematology:[/COLOR][/B] Study of blood and its constituent cells. [B][COLOR="purple"]xiii) Geology:[/COLOR][/B] Study of features and properties of earth and its constituents rocks. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Characteristics Of Living Organisms:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
Following are the main characteristics of living beings which are not present in non-living organisms. i) Metabolism ii) Growth iii) Irritability iv) Reproduction v) Movement vi) Nutrition vii) Respiration viii) Excretion [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="purple"]Virus:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] Viruses are the micro-organisms which are strict or obligate parasites of animals or plant cells. Many of the viruses are also parasites on bacteria. A large number of viruses cause diseases in plants and animals. [B][U][COLOR="purple"]Characteristics Of Virus:[/COLOR][/U][/B] A virus consists of two components, a protein coat and a core of nucleic acid which is either DNA or RNA. DNA viruses are called adenoviruses and RNA viruses are called retroviruses. The shape of a virus is due to its protein coat. Viruses are of many shapes i.e. rods, spherical, hexagonal or icosahedral. Sometimes their shape is complicated. Virus replicate inside a living cell and many viruses are synthesized along with their protein coats and nucleic acid. The nucleic acid contains instructions for the shape of the virus. [B][U][COLOR="purple"]Diseases Caused By viruses:[/COLOR][/U][/B] i) Polio ii) AIDS iii) Smallpox iv) Measles v) Hepatitis [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="purple"]Bacteria:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] [B][U][COLOR="purple"]Characteristics Of Bacteria:[/COLOR][/U][/B] Bacteria are unicellular prokaryotic organisms which generally divide by transverse binary fission. They possess rigid cell walls and act as pathogens Nucleus is not well organised No definite chloroplast, chlorophyll is dissolved in chromoplasm. There are three forms of bacteria which are: i) Round called Cocci ii) Rod like called Bacilli iii) Spiral called Spirrila [B][U][COLOR="purple"]Classification Of Bactria According To Mode Of Nutrition:[/COLOR][/U][/B] According to mode of nutrition, there are three types of Bactria: [B][COLOR="purple"]a) Parasitic:[/COLOR][/B] Devoid of chlorophyll Are heterotrophic and get food from living animals and plants [B][COLOR="purple"]b) Saprophytic[/COLOR][/B] Lack chlorophyll hence cannot prepare their own food. Get food from dead organic remains [B][COLOR="purple"]c) Autotrophic[/COLOR][/B] Contain chlorophyll Can synthesis food by photosynthesis Few get their food by chemosynthesis [B][U][COLOR="purple"]Reproduction In Bacteria[/COLOR][/U][/B] i) [B]Vegetative:[/B] By Binary Fission ii) [B]Asexual: [/B]By Formation of Endospores iii) [B]Sexual: [/B]By Conjugation |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Cell:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]Definition:[/COLOR][/U][/B] The smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. [B][U][COLOR="purple"]OR[/COLOR][/U][/B] The cell is the functional basic unit of life. It was discovered by Robert Hooke and is the functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. [B][U][COLOR="purple"]Cell Structure And Functions (Plant & Animal Cell)[/COLOR][/U][/B] [B][COLOR="purple"]1. Cell wall[/COLOR][/B] - Most commonly found in plant cells - Controls turgidity - Extracellular structure surrounding plasma membrane - Primary cell wall: extremely elastic - Secondary cell wall: forms around primary cell wall after growth is complete [B][COLOR="purple"]2. Plasma membrane[/COLOR][/B] - Outer membrane of cell that controls cellular traffic - Contains proteins (left, gray) that span through the membrane and allow passage of materials - Proteins are surrounded by a phospholipid bi-layer. [B][COLOR="purple"]3. Protoplasm[/COLOR][/B] -colourless, semitransparent, viscous granular fluid present inside the cell is called as protoplasm. -colloidal in nature and considered as physical basis of life. -exhibits the active streaming movement called cyclosis -it consists of water, protein, lipid or fats, carbohydrates, enzymes, salts, nucleic acid in a fixed proportion. -it is divided into Nucleus and Cytoplasm [B][COLOR="purple"]4. Cytoplasm[/COLOR][/B] -Protoplasm outside the nucleus is called cytoplasm -all the organelles are present in the cytoplasm like; [B][COLOR="purple"]i) Endoplasmic reticulum[/COLOR][/B] - Tubular network fused to nuclear membrane - Goes through cytoplasm onto cell membrane - Stores, separates, and serves as cell's transport system - Smooth type: lacks ribosomes - Rough type (pictured): ribosomes embedded in surface [B][COLOR="purple"]ii) Golgi apparatus[/COLOR][/B] - - Composed of numerous layers forming a sac - Works as the distribution and shipping department of the cells chemical product. [B][COLOR="purple"]iii) Lysosome[/COLOR][/B] - - Digestive 'plant' for proteins, lipids, and carbohydrates - Transports undigested material to cell membrane for removal - Vary in shape depending on process being carried out - Cell breaks down if lysosome explodes [B][COLOR="purple"]iv) Mitochondria[/COLOR][/B] - Second largest organelle with unique genetic structure - Double-layered outer membrane with inner folds called cristae - Energy-producing chemical reactions take place on cristae - Controls level of water and other materials in cell - Recycles and decomposes proteins, fats, and carbohydrates, and forms urea [B][COLOR="purple"]v) Ribosomes[/COLOR][/B] - Each cell contains thousands - Miniature 'protein factories' - Composes 25% of cell's mass - Stationary type: embedded in rough endoplasmic reticulum - Mobile type: injects proteins directly into cytoplasm [B][COLOR="purple"]vi) Vacuoles[/COLOR][/B] - Membrane-bound sacs for storage, digestion, and waste removal - Contains water solution - Contractile vacuoles for water removal (in unicellular organisms) [B][COLOR="purple"]vii) Chloroplasts[/COLOR][/B] - A plastid usually found in plant cells - Contain green chlorophyll where photosynthesis takes place [B][COLOR="purple"]viii) Cytoskeleton[/COLOR][/B] - Composed of microtubules - Supports cell and provides shape - Aids movement of materials in and out of cells [B][COLOR="purple"]ix) Centrioles[/COLOR][/B] - Paired cylindrical organelles near nucleus - Composed of nine tubes, each with three tubules - Involved in cellular division - Lie at right angles to each other [B][COLOR="purple"]5. Nucleus:[/COLOR][/B] -Control centre of the cell -Serves as information processing and administrative centre of the cell -Performs the following major functions: a) stores the cells hereditary material, or DNA b) coordinates the activities of the cell, which includes growth, metabolism, protein synthesis, and reproduction or cell division. [B][COLOR="purple"]i) Nuclear membrane[/COLOR][/B] - Surrounds nucleus - Composed of two layers - Numerous openings for nuclear traffic [B][COLOR="purple"]ii) Nucleolus[/COLOR][/B] - Spherical shape - Visible when cell is not dividing - Contains RNA for protein manufacture [B][COLOR="purple"]iii) Chromosomes[/COLOR][/B] - Usually in the form of chromatin - Contains genetic information - Composed of DNA - Thicken for cellular division - Set number per species (i.e. 23 pairs for human) [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="purple"]Difference Between Animal And Plant Cell:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] [B][COLOR="purple"]1) Cell Wall OR Cell Membrane[/COLOR][/B] - The outer boundary of plant cells is known as the cell wall, which is mainly composed of cellulose. - It helps the plant cell to maintain its shape. - The cell wall is absent in animal cell. - In animal cell the outer covering is known as cell membrane which is composed of lipid bilayer, proteins and carbohydrates. [B][COLOR="purple"]2) Plastids[/COLOR][/B] - Plants cells also contain organelles which are known as plastids. - The most common type of plastid is the chloroplast which contains chlorophyll. - These organelles or plastids are totally absent in animal cell. [B][COLOR="purple"]3) Vacuole[/COLOR][/B] - The main difference between the vacuole of animal and plants is their size. - The vacuole of plant cell is much bigger than that of animal cells. [B][COLOR="purple"]4) Centrosomes[/COLOR][/B] - In animal cells centrosomes are present, which are responsible for making some protein fibres which help in movement of chromosomes during division of cells. - Centrioles are absent in the plant cells. [B][COLOR="purple"]5) Lysosome[/COLOR][/B] - Lysosomes are not evident in plants while they are prominent in animal cells. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Cell Division:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
The process in which the cells divide and replicate. This process is the basis for growth and replication. There are two main types of cell division, which are as under: 1) Mitosis 2) Meiosis [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="purple"]Mitosis:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] A type of cell division in which a cell divides into two identical daughter cells each having same number of chromosomes as that of parent cell. [B][U][COLOR="purple"]Stages Of Mitosis:[/COLOR][/U][/B] There are four stages of mitosis, which are as under: i) Prophase ii) Metaphase iii) Anaphase iv) Telophase [B][COLOR="purple"]i) Prophase:[/COLOR][/B] - Prophase is the first phase of mitosis. - Chromatin material condenses and becomes visible - The nucleolus of the cell disappears - The nuclear membrane also disappears - Centrioles begin to move opposite ends of the cell [B][COLOR="purple"]ii) Metaphase:[/COLOR][/B] - Metaphase is the second stage of mitosis. - Chromosomes line up in the centre of the cell, separate and become a pair of identical chromosomes. - The chromatids become uncoiled and apart from each other. [B][COLOR="purple"]iii) Anaphase:[/COLOR][/B] - It is the third phase of mitosis. - During this phase each set of chromosomes move towards the opposite end of the cell. [B][COLOR="purple"]iv) Telophase:[/COLOR][/B] - The fourth phase of mitosis is known as Telophase. - During this phase spindle fibres disappear. - Nuclear membrane appears - Cell divides into two daughter cells - Nucleolus re-appear - The chromosomes disperse and are no longer visible. [B][COLOR="purple"][U]Significance Of Mitosis:[/U][/COLOR][/B] 1. Growth: The number of cells within an organism increases by mitosis and this is the basis of growth in multicellular organisms. 2. Cell Replacement: Cells are constantly sloughed off, dying and being replaced by new ones in the skin and digestive tract. When damaged tissues are repaired, the new cells must be exact copies of the cells being replaced so as to retain normal function of cells. 3. Regeneration: Some animals can regenerate parts of the body, and productions of new cells are achieved by mitosis. 4. Vegetative Reproduction: Some plants produce offspring which are genetically similar to themselves. These offspring are called clones. [B][U][CENTER][FONT="Garamond"][COLOR="purple"][SIZE="5"]Meiosis:[/SIZE][/COLOR][/FONT][/CENTER][/U][/B] A type of cell division in a cell divides into four daughter cells with having half number of chromosomes as compared to parent cell. [B][U][COLOR="purple"]Characteristics Of Meiosis:[/COLOR][/U][/B] Takes place in sexual reproduction at the time of formation of male and female gametes In animals it takes place during the formation of sperms and ova while in plants during spore formation Diploid cells reduce to haploid cells Consists of two consecutive divisions First division is reductional or meiotic and the second is simple mitotic division. [B][U][COLOR="purple"]Stages Of Meiotic Division:[/COLOR][/U][/B] i) Prophase I ii) Metaphase I iii) Anaphase I iv) Telophase I v) Prophase II vi) Metaphase II vii) Anaphase II viii) Telophase II [B][COLOR="purple"][U]Prophase I:[/U][/COLOR][/B] Prophase I consists of 5 sub stages, these are: [B][COLOR="purple"]a. Leptotene[/COLOR][/B] - Nucleus increases in size - Chromosomes become long and uncoiled threads - They become more visible [B][COLOR="purple"]b. Zygotene[/COLOR][/B] - Homologue (similar) chromosomes attract each other and form pairs. - This process is called synapses [B][COLOR="purple"]c. Pachytene[/COLOR][/B] - Chromosomes become condensed due to widening of coils - They form chiasmata i.e. cross each other in double nature or bivalents. [B][COLOR="purple"]d. Diplotene[/COLOR][/B] - Homologous chromosomes go apart from each other except at chiasmata - Chromosomes become more short and thicker [B][COLOR="purple"]e. Diakinesis[/COLOR][/B] - The bivalents become more apart. - Chromosomes become deeply stained - Nucleolus and nuclear membrane disappear and spindles become distinct [B][U][COLOR="purple"]Metaphase I:[/COLOR][/U][/B] - Chromosomes now rearrange themselves in an equatorial line - Spindles attach to the centrosome of the chromosomes [B][U][COLOR="purple"]Anaphase I:[/COLOR][/U][/B] - Spindles start to contract - Split the tetrahedral chromosomes into two chromatids and drag them to opposite poles - Here the reduction takes place. [B][U][COLOR="purple"]Telophase I:[/COLOR][/U][/B] - Spitted chromosomes reach to opposite poles - Nucleolus and nuclear membrane reappear - At the end of Telophase I, prophase II starts. [B][U][COLOR="purple"]Prophase II:[/COLOR][/U][/B] - Chromatin network breaks into bivalent chromosomes - Nuclear membrane and nucleolus disappear and spindles start to reappear [COLOR="Purple"][B][U]Metaphase II:[/U][/B][/COLOR] - Bivalent chromosomes rearrange themselves at equator - Spindles attach to the centrosomes of each chromosome [B][U][COLOR="purple"]Anaphase II:[/COLOR][/U][/B] - Spindles contract and split the chromosomes longitudinally into two chromatids - Each chromatid travel to opposite pole [B][U][COLOR="purple"]Telophase II:[/COLOR][/U][/B] - Each chromatid reach to the opposite pole - Spindles disappear and nuclear membrane and nucleoli reappear - As a result 4 nuclei are formed [B][U][COLOR="purple"]Significance Of Meiosis:[/COLOR][/U][/B] - To allow trait inheritance in offspring - To maintain diploid number in each generation - To ensure the production of haploid gametes in sexual reproduction - To produce genetic variations among offspring |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Classification Of Plants:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
Plants are those organisms which contain chlorophyll and synthesize their own food through photosynthesis. Plants are divided into: 1) Flowering Plants OR Phanerogams 2) Non-Flowering Plants OR Cryptogams [B][U][COLOR="purple"]Flowering Plants: [/COLOR][/U][/B] Flowering plants are those plants which contain seed. These are known as Phanerogams. They are further subdivided into: i) Gymnosperms ii) Angiosperms [B][U][COLOR="purple"]Gymnosperms:[/COLOR][/U][/B] Gymnosperms are those flowering plants which contain naked and unprotected seeds. [B][COLOR="purple"]Examples:[/COLOR][/B] Pine, Fir, Cedar, Spruce and Cypress etc. [B][U][COLOR="purple"]Angiosperms:[/COLOR][/U][/B] Angiosperms are those flowering plants whose seeds are protected by a fruit or seed pod. [B][COLOR="purple"]Examples:[/COLOR][/B] Grass, Crops, Vegetables, Fruits and weeds. [B][U][COLOR="purple"]Non-Flowering Plants:[/COLOR][/U][/B] Non-Flowering plants are also known as cryptogams. These are the plants which do not have seed or in other words they are seedless. Following are the main characteristics of these plants: - They reproduce by spores - They have long life - They have no long fibres - They cannot grow to greater size - They generally have simple structure, except ferns. [B][U][COLOR="purple"]Examples[/COLOR][/U][/B]: Moses, Ferns, Algae. [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="purple"]Flower & Its Parts:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] The flower is the reproductive part of the plant. It is mainly concerned with formation of seeds. It is regarded as the modified shoot for the purpose of reproduction. [B][U][COLOR="purple"]Parts Of Flower:[/COLOR][/U][/B] A typical flower consists of a short axis known as the thalamus, on which floral leaves are inserted in four distinct whorls, which are as under: i) Calyx ii) Corolla iii) Androecium iv) Gynaecium [B][U][COLOR="purple"]Calyx:[/COLOR][/U][/B] Calyx is the outermost whorl of floral leaves called sepals. The sepals can be defined as the green and leaf like structures which are mainly concerned with the protective function. [B][U][COLOR="purple"]Corolla:[/COLOR][/U][/B] Corolla is the second whorl of floral leaves called petals. The petals are beautifully coloured which are responsible for the attraction to the insects towards them. [B][U][COLOR="purple"]Androecium:[/COLOR][/U][/B] The third whorl of the leaves consists of stamens. It is considered as the male part of the flower. [B][U][COLOR="purple"]Gynaecium:[/COLOR][/U][/B] Gynaecium is the inner most whorl of the floral leaves called carpels. It is considered as the female part of the flower. [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Parts Of Plants:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] i) Ginger: Modified Stem (rhizome) and it is also a root. ii) Cinnamon: Bark of stem iii) Radish: Root iv) Potato: Stem (tuber) v) Peanut: Seed vi) Saffron: Stigma/flower vii) Almond: Fruit viii) Chillies: Fruit ix) Spinach: Leaves x) Tomato: Fruit xi) Turnip: Root xii) Carrot: Root xiii) Cucumber: Fruit |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Photosynthesis:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]Definition:[/COLOR][/U][/B] Photosynthesis is a process in which plants manufacture their food (simple carbohydrates) in the presence of chlorophyll and sunlight by the combination of carbon dioxide and water. [B][U][COLOR="purple"]Raw Material For Photosynthesis:[/COLOR][/U][/B] i) Carbon dioxide: Taken from air ii) Water: Absorbed by roots from soil iii) Sunlight: From Sun iv) Chlorophyll: green pigment present in leaves [B][U][COLOR="purple"]By-Products Of Photosynthesis:[/COLOR][/U][/B] i) Carbohydrates (simple sugar): used by plants as a food material and excess of it is converted into starch ii) Oxygen: Released into air [B][U][COLOR="purple"]Importance Of Photosynthesis:[/COLOR][/U][/B] i) Major process of food production in plants ii) Utilization of CO2 of the atmosphere and liberation of oxygen iii) Important in reducing CO2 of the atmosphere which is dangerous for the human beings as well as animal health. [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Pollination:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] [B][U][COLOR="purple"]Definition:[/COLOR][/U][/B] Pollination is the phenomenon of transfer of pollen from male reproductive organ (anther) to female reproductive organ (stigma) in flowering plants through biological or physical agency. [B][U][COLOR="purple"]Types Of pollination:[/COLOR][/U][/B] There are two types of Pollination [B][COLOR="purple"]i) Self-Pollination:[/COLOR][/B] In this type of pollination pollens are transferred to the stigma in the same flower. Some plants are by nature self-pollinated as wheat and grasses. [B][COLOR="purple"]ii) Cross Pollination:[/COLOR][/B] In this type the pollen grains are transferred from the anther of one flower to the stigma of another flower. The cross pollination is considered and advantageous to the plant as the seeds produced by cross-pollination are usually greater in number and the plant germinated from them are superior in vigour, height and weight. [B][U][COLOR="purple"]Vehicles For Pollination:[/COLOR][/U][/B] Vehicles for pollination are animals, water, wind and insects. Therefore cross pollination may be: a) Entomophily-by insects b) Anemophily-by wind c) Hydrophily-by water d) Zoophily-by animals [B][U][COLOR="purple"]Importance Of Pollination:[/COLOR][/U][/B] Vital process for reproduction in plants Reproduction is carried out by reproductory organs of plants due to pollination It is the process by which seeds are produced. [B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="purple"]Fertilization:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B] The fusion of male and female gametes is called fertilization. [B][U][COLOR="purple"]Types Of Fertilization:[/COLOR][/U][/B] Following are the major types of fertilization: i) External Fertilization ii) Internal Fertilization iii) Self-Fertilization iv) Cross-Fertilization [B][U][COLOR="purple"]External Fertilization:[/COLOR][/U][/B] This type of fertilization is generally observed I simple aquatic animals. In such animals both ova and sperms are released into the water where fertilization occurs. In terms of evolution external fertilization is of primitive type and is not better biologically as compared to internal fertilization. [B][U][COLOR="purple"]Internal Fertilization:[/COLOR][/U][/B] In the internal fertilization the females keep ova inside their bodies and males deposit sperms within the tube of reproductive tacts of females. For all land animals internal fertilization is almost must because sperms are quickly killed by dehydration. In terms of evolution internal fertilization is highly evolved and much better biologically as compared to external fertilization. [B][U][COLOR="purple"]Self-Fertilization:[/COLOR][/U][/B] Self-fertilization occurs within the same animal. It is that fertilization in which sperms are used by the ovaries of same animal e.g. Tapeworm [B][U][COLOR="purple"]Cross-fertilization:[/COLOR][/U][/B] Cross-fertilization is the process in which sperms of one animal are transferred into the body of another animal e.g. Earthworm. |
[B][U][CENTER][FONT="Georgia"][SIZE="5"][COLOR="Purple"]Animals:[/COLOR][/SIZE][/FONT][/CENTER][/U][/B]
[B][U][COLOR="purple"]Types Of Animals:[/COLOR][/U][/B] i) Invertebrates: Animals having no backbone or vertebral column. ii) Vertebrates: Animals with backbone or vertebral column. [B][U][COLOR="purple"]Classification Of Invertebrates:[/COLOR][/U][/B] The invertebrates are classified into following categories: i) Phylum Protozoa ii) Phylum Porifera iii) Phylum Coelentrata iv) Phylum Platyhelminthes v) Phylum Nematode vi) Phylum Annelida vii) Phylum Mollusca viii) Phylum Arthropoda ix) Phylum Echinodermata [B]Following are the most common examples of invertebrate animals with their relative phyla:[/B] - Euglena: Phylum Protozoa - Paramecium: Phylum Protozoa - Amoeba: Phylum Protozoa - Sponges: Phylum Porifera - Hydra: Phylum Coelentrata - Jelly fish: Phylum Coelentrata - Tapeworm: Phylum Platyhelminthes - Ascaris: Phylum Nematode - Hookworm: Phylum Nematode - Filaria: Phylum Nematode - Snails: Phylum Mollusca - Squids: Phylum Mollusca - Cockroach: Phylum Arthropoda - Honey bee: Phylum Arthropoda - Mosquito: Phylum Arthropoda - Butter fly: Phylum Arthropoda [B][U][COLOR="purple"]Classification Of Vertebrates:[/COLOR][/U][/B] Vertebrates have been divided into following five major classes: i) Fishes ii) Amphibians iii) Reptilian iv) Birds v) Mammals [B][U][COLOR="purple"]Some Animals & Their Location[/COLOR][/U][/B] i) Blue whale: Found in all oceans ii) Panda: China iii) Dolphin: In seas iv) Porpoises: v) Kangaroo: Australia vi) Snow Leopard: Central Asia vii) Yak: Central Asia viii) Llama: South America ix) Ibex: Wild mountain goat x) Cobra: South Asia xi) Alligator: N.America xii) Tortoise: Water xiii) Rattle Snake: America xiv) Lizards: xv) Crocodiles: xvi) Ostrich: Deserts Of Africa xvii) Penguin: Antarctic Region xviii) Kiwi: New Zealand xix) Rhea: South America xx) Emu: Australia xxi) Shark: Found in all oceans xxii) Trout: Fresh water fish xxiii) Cod: [B][U][COLOR="purple"]Scavenger:[/COLOR][/U][/B] Scavengers are the animals that Clean up after the other animals by consuming their leavings and sometimes prey on sick or dying animals or consume dead bodies. Scavengers are also called detritus feeders. Vultures, coyotes, jackals, hyenas and wild dogs are scavengers which eat the left over prey or dead bodies of hunted animals. |
[QUOTE=Roshan wadhwani;375341]
Scavengers are the animals that Clean up after the other animals by consuming their leavings and sometimes prey on sick or dying animals or consume dead bodies. Scavengers are also called detritus feeders. Vultures, coyotes, jackals, hyenas and wild dogs are scavengers which eat the left over prey or dead bodies of hunted animals.[/QUOTE] Brother Roshan Wadhwani, let me make an addition (not a correction) to "Scavangers" here. Environment is made of two components: living components and non-living components: Living components include Producers, Consumers and Decomposers. Scavengers and micro-organisms fall into the category of [B]decomposers[/B] [I]which feed on dead plants and animals and break them down into smaller parts.[/I] Your effort, anyway, is worthwhile. Keep it up! |
The Baikonur Cosmodrome
[COLOR="Black"][U][INDENT][INDENT][INDENT][CENTER][B]The Baikonur Cosmodrome , also called Tyuratam[1], is the world's first and largest operational space launch facility. It is located in the desert steppe of Kazakhstan[/B][/CENTER][/INDENT][/INDENT][/INDENT][/U],[/COLOR]
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