friends,

Before posting the answers of 1996 paper ,I am posting 2008 paper with answers.It is not complets ,but a part of the paper and related topics are included in the following paragraphs.

PAPER 2008 EDS
Milky Way, the large, disk-shaped aggregation of stars, or galaxy, that includes the Sun and its solar system. In addition to the Sun, the Milky Way contains about 400 billion other stars. There are hundreds of billions of other galaxies in the universe, some of which are much larger and contain many more stars than the Milky Way.
Star: massive shining sphere of hot gas, generates energy by thermonuclear reactions, e.g. the Sun. Stars are made chiefly of hydrogen and a smaller amount of helium. Even the most abundant of the other elements present in stars—oxygen, carbon, neon, and nitrogen—are generally present in very small quantities.
The next nearest star is Proxima Centauri
Planet , a round body in space that orbits a star.
A planet shines by reflecting light and not by releasing nuclear energy the way a star does
Our solar system has eight major planets—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune—and a number of small, dwarf planets, including Pluto, Eris, and Ceres.
A planet-like body that revolves around a larger planet is called a satellite or moon rather than a planet. Planets are distinct from asteroids and comets, smaller bodies that also orbit stars.
Asteroid, small rocky or metallic body that orbits the Sun. Hundreds of thousands of asteroids exist in the solar system. Asteroids range in size from a few meters to over 500 km (300 mi) wide. They are generally irregular in shape and often have surfaces covered with craters
Most asteroids are found between the orbits of the planets Mars and Jupiter in a wide region called the asteroid belt
Like icy comets, asteroids are primitive objects left over from the time when the planets formed.(4.6 BILLION YEARS AGO)
Comet, small icy body in space that sheds gas and dust.
Comets typically have highly elliptical (oval-shaped), off-center orbits that swing near the Sun. When a comet is heated by the Sun, some of the ice on the comet’s surface turns into gas directly without melting. The gas and dust freed from the ice can create a cloud (coma) around the body (nucleus) of the comet. More gas and dust erupt from cracks in the comet’s dark crust. High-energy charged particles emitted by the Sun, called the solar wind, can carry the gas and dust away from the comet as a long tail that streams into space. Gas in the tail becomes ionized and glows as bluish plasma, while dust in the tail is lit by sunlight and looks yellowish. This distinctive visible tail is the origin of the word comet, which comes from Greek words meaning “long-haired star.”
Nuclear Energy, energy released during the splitting or fusing of atomic nuclei. The energy of any system, whether physical, chemical, or nuclear, is manifested by the system’s ability to do work or to release heat or radiation. The total energy in a system is always conserved, but it can be transferred to another system or changed in form.
First, the energy per fission is very large. In practical units, the fission of 1 kg (2.2 lb) of uranium-235 releases 18.7 million kilowatt-hours as heat. Second, the fission process initiated by the absorption of one neutron in uranium-235 releases about 2.5 neutrons, on the average, from the split nuclei. The neutrons released in this manner quickly cause the fission of two more atoms, thereby releasing four or more additional neutrons and initiating a self-sustaining series of nuclear fissions, or a chain reaction, which results in continuous release of nuclear energy. Only the uranium-235 is easily fissionable
The fusion of two light nuclei into a heavier one. The energy radiated by stars, including the Sun, arises from such fusion reactions deep in their interiors.
Antibiotics (Greek anti, “against”; bios, “life”) are chemical compounds used to kill or inhibit the growth of infectious organisms.eg anti bacterial antimalarials, antivirals, or antiprotozoals. Penicillin, any one of a group of antibiotics derived from the fungus Penicillium .The action of natural penicillin was first observed in 1928 by British bacteriologist Sir Alexander Fleming.
Virus (life science), infectious agent found in virtually all life forms, including humans, animals, plants, fungi, and bacteria
Viruses consist of genetic material—either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA)—surrounded by a protective coating of protein, called a capsid, with or without an outer lipid envelope. Viruses are between 20 and 100 times smaller than bacteria and hence are too small to be seen by light microscopy. Viruses vary in size from the largest poxviruses of about 450 nanometers (about 0.000014 in) in length to the smallest polioviruses of about 30 nanometers (about 0.000001 in). Viruses are not considered free-living, since they cannot reproduce outside of a living cell; they have evolved to transmit their genetic information from one cell to another for the purpose of replication.
Viruses often damage or kill the cells that they infect, causing disease in infected organisms. A few viruses stimulate cells to grow uncontrollably and produce cancers. Although many infectious diseases, such as the common cold, are caused by viruses, there are no cures for these illnesses. The difficulty in developing antiviral therapies stems from the large number of variant viruses that can cause the same disease, as well as the inability of drugs to disable a virus without disabling healthy cells
Immunization, also called vaccination or inoculation, a method of stimulating resistance in the human body to specific diseases using microorganisms—bacteria or viruses—that have been modified or killed. These treated microorganisms do not cause the disease, but rather trigger the body's immune system to build a defense mechanism that continuously guards against the disease. If a person immunized against a particular disease later comes into contact with the disease-causing agent, the immune system is immediately able to respond defensively.
Active immunization:The active components of the vaccinations are antigens, substances found in the disease-causing organism that the immune system recognizes as foreign. In response to the antigen, the immune system develops either antibodies or white blood cells called T lymphocytes, which are special attacker cells. Immunization mimics real infection but presents little or no risk to the recipient. Some immunizing agents provide complete protection against a disease for life. Other agents provide partial protection, meaning that the immunized person can contract the disease, but in a less severe form
Some immunizing agents require repeated inoculations—or booster shots—at specific intervals. These vaccines are usually considered risky for people who have a damaged immune system. such as those infected with the virus that causes acquired immunodeficiency syndrome (AIDS) or those receiving chemotherapy for cancer or organ transplantation. scientists use an organism or part of one that has been modified so that it has a low risk of causing illness but still triggers the body’s immune defenses against disease. One type of vaccine contains live organisms that have been attenuated—that is, their virulence has been weakened. This procedure is used to protect against yellow fever, measles, smallpox, and many other viral diseases. Immunization can also occur when a person receives an injection of killed or inactivated organisms that are relatively harmless but that still contain antigens. This type of vaccination is used to protect against bacterial diseases such as poliomyelitis, typhoid fever, and diphtheria.

Some vaccines use only parts of an infectious organism that contain antigens, such as a protein cell wall or a flagellum. Known as acellular vaccines,
Active immunization can also be carried out using bacterial toxins that have been treated with chemicals so that they are no longer toxic, even though their antigens remain intact
This method is used in vaccinating against tetanus, botulism, and similar toxic diseases
passive immunization
In this method, vaccines contain antibodies obtained from the blood of an actively immunized human being or animal. The antibodies last for two to three weeks, and during that time the person is protected against the disease. Although short-lived, passive immunization provides immediate protection, unlike active immunization, which can take weeks to develop. Consequently, passive immunization can be lifesaving when a person has been infected with a deadly organism.

Plastics, materials made up of large, organic (carbon-containing) molecules that can be formed into a variety of products. The molecules that compose plastics are long carbon chains that give plastics many of their useful properties. In general, materials that are made up of long, chainlike molecules are called polymers. The word plastic is derived from the words plasticus (Latin for “capable of molding”) and plastikos (Greek “to mold,” or “fit for molding”). Plastics can be made hard as stone, strong as steel, transparent as glass, light as wood, and elastic as rubber. Plastics are also lightweight, waterproof, chemical resistant, and produced in almost any color. More than 50 families of plastics have been produced
GENERAL PROPERTIES OF PLASTICS
Plastics possess a wide useful variety of properties and are relatively inexpensive to produce. They are lighter than many materials of comparable strength, and unlike metals and wood, plastics do not rust or rot. Most plastics can be produced in any color. They can also be manufactured as clear as glass, translucent (transmitting small amounts of light), or opaque (impenetrable to light).
Plastics have a lower density than that of metals, so plastics are lighter. Most plastics vary in density from 0.9 to 2.2 g/cm3 (0.45 to 1.5 oz/cu in), compared to steel’s density of 7.85 g/cm3 (5.29 oz/cu in). Plastic can also be reinforced with glass and other fibers to form incredibly strong materials. For example, nylon reinforced with glass can have a tensile strength (resistance of a material to being elongated or pulled apart) of up to 165 Mega Pascal (24,000 psi).
Plastics have some disadvantages. When burned, some plastics produce poisonous fumes. Although certain plastics are specifically designed to withstand temperatures as high as 288° C (550° F), in general plastics are not used when high heat resistance is needed. Because of their molecular stability, plastics do not easily break down into simpler components. As a result, disposal of plastics creates a solid waste problem (see Plastics and the Environment


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a) Enzymesare biological catalysts which have multiple function in the body.
b) The difference between electrical charges at the two ends of a conductor is called Potential difference.
c) The branch of zoology which deals with the study of insects is called Entomology
d) Electric current is measured by an Ammeter.
e) Dry ice is solid carbon dioxide.
f) Fuels formed from animal and plant matter that lived thousands of years ago are known as fossil fuels
g) Light with larger wavelength than that of the red colour is called infrared
h) Penicillin was discovered by Alexender Fleming.
i) Medulla Oblongata connects thesmall brainwith the spinal chord.
j) The pH of normal human blood is 7.4.

8. What do the following scientific abbreviations stand for?

a) LPG liquuified patrolium gas

b) TNT Tri niotro toline

c ) RNA ribonucliec acid

d) CNG compressed naturtal gas

e) ATP adenosine tri phosphate

f) RBC Red Blood Cells

g) ECG electro cardio gram

h) PVC poly vinyle chloride

i) RAM random access memory

j) CFC chloro flouro carbons

regards

9. Write short notes on any two of the following

a) Acid rain
The problem begins with the production of sulfur dioxide and nitrogen oxides from the burning of fossil fuels, such as coal, natural gas, and oil, and from certain kinds of manufacturing. Sulfur dioxide and nitrogen oxides react with water and other chemicals in the air to form sulfuric acid, nitric acid, and other pollutants. These acid pollutants reach high into the atmosphere, travel with the wind for hundreds of miles, and eventually return to the ground by way of rain, snow, or fog, and as invisible “dry” forms
Acid rain leaches nutrients from soils, slows the growth of trees, and makes lakes uninhabitable for fish and other wildlife. In cities, acid pollutants corrode almost everything they touch, accelerating natural wear and tear on structures such as buildings and statues. Acids combine with other chemicals to form urban smog, which attacks the lungs, causing illness and premature deaths





b) Green house effect

Greenhouse Effect, the capacity of certain gases in the atmosphere to trap heat emitted from Earth’s surface, thereby insulating and warming the planet. Without the thermal blanketing of the natural greenhouse effect, Earth’s climate would be about 33°C (about 59°F) cooler—too cold for most living organisms to survive.

The greenhouse effect results from the interaction between sunlight and the layer of greenhouse gases in the atmosphere that extends up to 100 km (60 mi) above Earth’s surface. Sunlight is composed of a range of radiant energies known as the solar spectrum, which includes visible light, infrared light, gamma rays, X rays, and ultraviolet light. When the Sun’s radiation reaches Earth’s atmosphere, some 25 percent of the energy is reflected back into space by clouds and other atmospheric particles. About 20 percent is absorbed in the atmosphere. For instance, gas molecules in the uppermost layers of the atmosphere absorb the Sun’s gamma rays and X rays. The Sun’s ultraviolet radiation is absorbed by the ozone layer, located 19 to 48 km (12 to 30 mi) above Earth’s surface.

About 50 percent of the Sun’s energy, largely in the form of visible light, passes through the atmosphere to reach Earth’s surface. Soils, plants, and oceans on Earth’s surface absorb about 85 percent of this heat energy, while the rest is reflected back into the atmosphere—most effectively by reflective surfaces such as snow, ice, and sandy deserts. In addition, some of the Sun’s radiation that is absorbed by Earth’s surface becomes heat energy in the form of long-wave infrared radiation, and this energy is released back into the atmosphere.
Certain gases in the atmosphere, including water vapor, carbon dioxide, methane, and nitrous oxide, absorb this infrared radiant heat, temporarily preventing it from dispersing into space. As these atmospheric gases warm, they in turn emit infrared radiation in all directions. Some of this heat returns back to Earth to further warm the surface in what is known as the greenhouse effect, and some of this heat is eventually released to space. This heat transfer creates equilibrium between the total amount of heat that reaches Earth from the Sun and the amount of heat that Earth radiates out into space. This equilibrium or energy balance—the exchange of energy between Earth’s surface, atmosphere, and space—is important to maintain a climate that can support a wide variety of life
The heat-trapping gases in the atmosphere behave like the glass of a greenhouse. They let much of the Sun’s rays in, but keep most of that heat from directly escaping. Because of this, they are called greenhouse gases. Without these gases, heat energy absorbed and reflected from Earth’s surface would easily radiate back out to space, leaving the planet with an inhospitable temperature close to –19°C (2°F), instead of the present average surface temperature of 15°C (59°F).






c) Ozone depletion

Ozone Layer, a region of the atmosphere from 19 to 48 km (12 to 30 mi) above Earth's surface. Ozone concentrations of up to 10 parts per million occur in the ozone layer. The ozone forms there by the action of sunlight on oxygen. This action has been taking place for many millions of years, but naturally occurring nitrogen compounds in the atmosphere apparently have kept the ozone concentration at a fairly stable level.

The ozone layer of the atmosphere protects life on Earth by absorbing harmful ultraviolet radiation from the Sun. If all the ultraviolet radiation given off by the Sun were allowed to reach the surface of Earth, most of the life on Earth’s surface would probably be destroyed. Short wavelengths of ultraviolet radiation, such as UV-A, B, and C, are damaging to the cell structure of living organisms. Fortunately, the ozone layer absorbs almost all of the short-wavelength ultraviolet radiation and much of the long-wavelength ultraviolet radiation given off by the Sun.

In the 1970s scientists became concerned when they discovered that chemicals called chlorofluorocarbons, or CFCs (see Fluorine)—long used as refrigerants and as aerosol spray propellants—posed a possible threat to the ozone layer. Released into the atmosphere, these chlorine-containing chemicals rise into the upper stratosphere and are broken down by sunlight, whereupon the chlorine reacts with and destroys ozone molecules—up to 100,000 per CFC molecule. The use of CFCs in aerosols has been banned in the United States and elsewhere. Other chemicals, such as bromine halocarbons, as well as nitrous oxides from fertilizers, may also attack the ozone layer. Thinning of the ozone layer is predicted to cause increases in skin cancer and cataracts, damage to certain crops and to plankton and the marine food web, and an increase in atmospheric carbon dioxide (Global Warming) due to the decrease in plants and plankton.

reference:
encarta,
Imtiaz shahid

regards

This comparison question is very important accordind to the new criterion.

14. Differentiate between any five of the following

a) Thermoplastics and thermosetting plastics

Thermoplastics :Thermoplastics can be repeatedly softened by heating and hardened by cooling.Thermoplastic molecules, which are linear or slightly branched, do not chemically bond with each other when heated. Instead, thermoplastic chains are held together by weak van der Waal forces (weak attractions between the molecules) that cause the long molecular chains to clump together like piles of entangled spaghetti. Thermoplastics can be heated and cooled, and consequently softened and hardened, repeatedly, like candle wax. For this reason, thermoplastics can be remolded and reused almost indefinitely.
in few words you can say
1.Thermoplastics can be repeatedly softened by heating and hardened by cooling.
2.Thermoplastic molecules do not chemically bond with each other when heated.
2.examples are Polystyrene and polyethylene .

thermosetting plasticsThermosetting plastics, on the other hand, harden permanently after being heated once.Thermosetting plastics consist of chain molecules that chemically bond, or cross-link, with each other when heated. When thermosetting plastics cross-link, the molecules create a permanent, three-dimensional network that can be considered one giant molecule. Once cured, thermosetting plastics cannot be remelted, in the same way that cured concrete cannot be reset. Consequently, thermosetting plastics are often used to make heat-resistant products, because these plastics can be heated to temperatures of 260° C (500° F) without melting.

in few words you can say

1.harden permanently after being heated once.
2.molecules that chemically bond when heated.
3examples are polyurethane and phenolic.



b) Lunar eclipse and solar eclipse

A lunar eclipse occurs when Earth is between the Sun and the Moon, and Earth’s shadow darkens the Moon. A solar eclipse occurs when the Moon is between the Sun and Earth, and the Sun’s shadow moves across the face of Earth. An eclipse is called a total eclipse if the light is completely blocked or a partial eclipse if the light is only partly blocked.



c) Asteroid and meteorite

Asteroid, small rocky or metallic body that orbits the Sun. Hundreds of thousands of asteroids exist in the solar system. Asteroids range in size from a few meters to over 500 km (300 mi) wide. They are generally irregular in shape and often have surfaces covered with craters

Meteorite, meteor that reaches the surface of Earth or of another planet before it is entirely consumed by heat and friction from the atmosphere. Meteors and meteorites originate as meteoroids in space. On Earth most meteoroids burn up as meteors before they can become meteorites. Meteoroids also strike bodies in space that lack atmospheres, such as the Moon and asteroids, becoming meteorites without being meteors.

meteor :Meteor, bright streak of light caused when a small solid body from outer space known as a meteoroid enters the atmosphere of Earth or another planet and is heated by friction from rapid motion through the air. The outer surface of the meteoroid melts and forms an envelope of extremely hot gas and air that radiates light. The meteoroid may burn up almost completely and fall as dust, or it may fragment or explode in midair. Remains of meteoroids that reach the surface are called meteorites.



d) Renewable and non-renewable energy resources

generally a form or forms of energy that are not based on fossil fuels but are renewable sources.they are mostly environmental friendly.
examples, Geothermal Energy; Solar Energy; Tidal Energy; and Wind Energy.

non-renewable energy resources: generally a form or forms of energy that are based on fossil fuels .they are not environmental friendly.
examples, natural gas, oil, wood.patrol etc.

e) Endothermic and exothermic reactionsChemical reactions can occur spontaneously if the reactants possess more potential energy (stored energy) than the products. This type of reaction occurs spontaneously because of the downhill energy path (from more potential energy to less). These reactions are called exothermic (heat-producing) reactions, because potential energy is converted to heat as the reactions proceed. Conversely, endothermic (heat-absorbing) reactions do not occur spontaneously because of the uphill energy path that exists. The products of endothermic reactions contain more potential energy than the reactants. As a result, energy must be added to trigger an endothermic reaction.


f) Star and planet
it has already been discussed in 2008 paper

g) Nuclear fission and nuclear fusion
it has already been discussed in 2008 paper


Encarta 2009. encyclopeda .

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12. Briefly describe the principle and function of a camera. Mention its essential parts along with brief comparison with an eye.
Answer: The most important tool of photography is the camera itself. Basically, a camera is a lighttight box with a lens on one side and light-sensitive film on the other.


Parts:
1.camera box
2.film
3.aperture or diaphragm and shutter
4.the lense
5.the viewing system

Cameras may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A camera generally consists of an enclosed hollow with an opening (aperture) at one end for light to enter, and a recording or viewing surface for capturing the light at the other end. A majority of cameras have a lens positioned in front of the camera's opening to gather the incoming light and focus all or part of the image on the recording surface. The diameter of the aperture is often controlled by a diaphragm mechanism, but some cameras have a fixed-size aperture.


Refraction is the phenomenon which makes image formation possible by the eye as well as by cameras and other systems of lenses.
Human eyes have often been compared to cameras. They are alike in terms of structure, but they have one fundamental difference in functioning mechanism.
Table: Similarities & the Difference between Camera and Human Eye

Function Camera Human Eye


Similarities
1. opening for light to enter aperture in Camera and pupil in eye
2. control the amount of light entering camera/eye
diaphragm control size of aperture in camera and iris muscles control size of pupil in eye
3. refract light glass biconvex lens in Camera .And
mainly cornea ; lens, aqueous & vitreous humor in eye
4. object of light action to form image photosensitive chemicals on film in camera and photoreceptors(rods & cones) in retina of eye.
5. absorb excessive light to prevent multiple images formation dark internal surface in camera and pigmented, dark choroid in eye

Difference
1. focusing mechanism change distance between lens & film in camera and change focal length of lens using ciliary muscles in eye.

for picture this link is useful
http://library.thinkquest.org/28030/eyeevo.htm

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CPU and its components
Abbreviation for central processing unit, and pronounced as separate letters. The CPU is the brains of the computer. Sometimes referred to simply as the central processor,but more commonly called processor, the CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.

it has 3 parts

1)Memory unit: It stores vital information.such as computer language codes.It has 2 parts.

a)Ramdom access memory
b)read only memory


2)The arithmetic logic unit (ALU), which performs arithmetic and logical operations.
3)The control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.


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HUMAN TEETH

Human teeth are made of four distinct types of tissue: enamel, dentin, pulp, and cementum. Enamel, the clear outer layer of the tooth above the gum line, is the hardest substance in the human body. In human teeth, the enamel layer is about 0.16 cm (about 0.06 in) thick and protects the inner layers of the teeth from harmful bacteria and changes in temperature from hot or cold food. Directly beneath the enamel is dentin, a hard, mineral material that is similar to human bone, only stronger. Dentin surrounds and protects the pulp, or core of the tooth. Pulp contains blood vessels, which carry oxygen and nutrients to the tooth, and nerves, which transmit pain and temperature sensations to the brain. The outer layer of the tooth that lies below the gum line is cementum, a bonelike substance that anchors the tooth to the jawbone.

The visible portion of the tooth is called the crown. Projections on the top of each crown, used primarily for chewing and grinding, are called cusps. The portion of the tooth that lies beneath the gum line is the root. The periodontal ligament anchors the tooth in place with small elastic fibers that connect the cementum in the root to a special socket in the jawbone called the alveolus.

A. Types of Human Teeth Adult humans typically have 32 teeth—16 in the upper jaw and 16 in the lower jaw—that fit together and work in concert to chew food. Teeth on the right side of each jaw are usually identical to the teeth on the left side and matching teeth on opposite sides are referred to as sets, or pairs. Humans are heterodonts—that is, they have teeth of different sizes and shapes that serve different functions, such as tearing and grinding. In contrast, the homodont teeth found in many animals are all the same size and shape, and perform the same function.

Humans have four types of teeth, each with a specific size, shape, and function. Adult humans have eight incisors, located at the front of the mouth—four in the upper jaw and four in the lower jaw. Incisors have a sharp edge that is used to cut food. On either side of the incisors are the canines, named for their resemblance to the pointy fangs of dogs. The upper canines are sometimes called eyeteeth. There are two canines in each jaw, and their primary role is to tear food. Behind the canines are the bicuspids, or premolars, flat teeth with pronounced cusps that grind and mash food. There are two sets, or four bicuspids, in each jaw. Behind the bicuspids are the molars, where the most vigorous chewing occurs. There are twelve molars—three sets in each jaw—referred to as the first, second, and third molars. Third molars are often called wisdom teeth; they developed thousands of years ago when human diets consisted of mostly raw and unprocessed foods that required the extra chewing and grinding power of a third set of molars. Today wisdom teeth are not needed for chewing and, because they can crowd other teeth, are often removed.

for human body see Imtiaz Shahid book

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FOR this question , a video by Mohsin Shah on this link

http://www.cssforum.com.pk/off-topic...deos-only.html

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EVERYDAY SCIENCE PAPER 1997

Note: Attempt TEN questions. All questions carry equal marks. Draw diagrams where necessary. Negative marking would be done for incorrect answers in Question Nos. 13 and 14.

1. Discuss the role and achievements of Muslim physicists during the 10th century.

2. Explain the structure of Earth and its atmosphere.

3. Write short notes on any two of the following
(i) Solar eclipse
(ii) Thermoplastics
(iii) Non-renewable energy resources.

4. What are pesticides? Discuss their classification, commonly in use with agronomists.


5. What is the difference between

(i) BIT and BYTE
(ii) RAM and ROM
(iii) C.U. and A.L.U
(iv) Hardware and Software
(v) Personal computer and mainframe

6. Explain any five of the following terms (innot more than four lines each):

(i) Osmosis glycolysis
(ii) Phototaxis
(iii) Transpiration
(iv) Saponification
(v) Emulsion

7. Fill in the blanks

(i) A sheet of muscles called ___________ separates the chest from the abdomen.
(ii) In the human body, blood-clotting factor is produced by the ___________
(iii) Human blood is able to carry large amounts of oxygen because of the chemical ___________.
(iv) The living part of a plant cell is composed of a nucleus and ___________.
(v) The pattern for building protein molecules is stored in the ___________.
(vi) Anvil and stirrup are names of bones present in the ___________.
(vii) The front of the eye is covered with a tough transparent material called ___________.
(viii) The young plant inside a grain of wheat is called the ___________
(ix) In born behaviour that involve only one part of the body are called ___________
(x) The smallest branches of an artery lead into tiny blood vessels called ___________.

8. What are Exocrine glands? Give names of any four along with the name of their secretion.


9. Which quantity do the following units measure:

(i) Volt
(ii) Coloumb
(iii) Walt
(iv) Ohm
(v) Mho
(vi) Ampere
(vii) Dyne
(viii) Celcius
(ix) Joule
(x) Calorie

10. Give scientific reasons (in not more than four lines each) for the following:

(i) Meat takes longer to cook on the mountains
(ii) Water remains cool in earthen pitchers
(iii) Ice and salt mixture is used as a freezing agent by manual ice cream makers.
(iv) It is not advisable to sleep under trees during the night.
(v) Greenhouse operators paint their glass roofs white in summer.

11. Which par/organ of the human body do the following belong:

(i) Eustachian tube
(ii) Cartilage
(iii) Auricle
(iv) Tendon
(v) Dendrites

12.Briefly describe the solar system. Name its members outlines the main characteristics of any two members.


13. Fill in the blanks.

(i) Insulin is produced in the human body by the ___________. (Liver, Pancreas, Gallbladder)
(ii) In an animal cell protein is synthesized in the ___________. (Nucleus, Mitochondria, Ribosome)
(iii) Chemically finger nails are made up of ___________. (Carbohydrate, Protein, Minerals)
(iv) Muscle stiffness is a symptom caused by the disease ___________ (Polio, Tetanus, Rabies)
(v) Animals which obtain their food from dead organisms are called ___________. (Carnivores, Scavengers, Saprophytes)
(vi) ___________ is not affected by cooking. (Ascorbic acid, Thiamin, Riboflavin)
(vii) Rickets is caused by the deficiency of vitamin ___________. (A, D, K)
(viii) The number of chromosomes in the spermatozoa is ___________ (Twenty-two, twenty-three, Forty-six.
(ix) The fat in our food is digested by the enzymes ___________. (clipase, lactase, trypsin)
(x) The most abundant element in the human body is ___________. (Carbon, Hydrogen, Oxygen)

14. Which of the following statements are false and which are true.

(i) Sound is a form of energy
(ii) A fraction of sunlight is refracted as it enters the earth’s atmosphere.
(iii) The energy possessed by a water fall is kinetic energy.
(iv) Rainbows are produced by the reflection of light through raindrops.
(v) Light switches in our homes are connected in parallel series.
(vi) Generators convert mechanical energy into electricity.
(vii) Modern incandescent bulbs contain filaments made of copper.
(viii) A steam engine cannot be powered by fossil fuels.
(ix) Nuclear energy is a cheap source of abundant electricity.
(x) Oil bulbs cleaner and is less damaging to the environment than coal as a fuel.

15. Match words of List A with those of List B

A....................B

Protein............Fat
Magnesium......Milk
Carotene.........Ozone
Bauxite...........Nitrogen
Haemitite........Amino acid
Casein............Vitamin A
Pancreas.........Aluminium
Quartz............Chlorophyll
Chlorofluorocarbon...Iron
Urea...............Silicon

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