Every Day Science Paper - 1995
Partial Solution
1. Which of the following statements are true and which are false.
a) Cryptograms are non-flowering plants.
False
b) Reserve food material is usually stored as glycogen in plants.
False
c) Streptococcus is a gram negative bacteria
False
d) Spinach is a good source of vitamin K.
True
e) Insulin is a hormone secreted by the spleen.
False
f) Femur is a bone of the forearm.
False
g) The moon has no atmosphere.
True
h) Excessive burning of fossil fuels cause acid rain.
True
i) Twenty-first of June is the longest day of the year in the northern hemisphere.
True
j) Electricity is a secondary source of energy.
True
2. Define any FIVE of the following scientific terms:
a) Doping
b) Immunization
c) Pasteurization
d) Modulation
e) Catabolism
f) Reprocessing of reactor fuel
Answers:
a) Doping: is adding impurities to semiconductor materials in order to change their electrical characteristics.
b) 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.
c) Pasteurization: Pasteurization, process of heating a liquid, particularly milk, to a temperature between 55° and 70° C (131° and 158° F), to destroy harmful bacteria without materially changing the composition, flavor, or nutritive value of the liquid. The process is named after the French chemist Louis Pasteur, who devised it in 1865 to inhibit fermentation of wine and milk. Milk is pasteurized by heating at a temperature of 63° C (145° F) for 30 minutes, rapidly cooling it, and then storing it at a temperature below 10° C (50° F).
d) Modulation: change sound: to change the tone, pitch, or volume of sound, e.g. of a musical instrument or the human voice
e) Catabolism: constructive metabolism, is the process of synthesis required for the growth of new cells and the maintenance of all tissues. Catabolism, or destructive metabolism, is a continuous process concerned with the production of the energy required for all external and internal physical activity. Catabolism also involves the maintenance of body temperature and the degradation of complex chemical units into simpler substances that can be removed as waste products from the body through the kidneys, intestines, lungs, and skin.
f) Reprocessing of reactor fuel:
The spent fuel still contains almost all the original uranium-238, about one-third of the uranium-235, and some of the plutonium-239 produced in the reactor. In cases where the spent fuel is sent to permanent storage, none of this potential energy content is used. In cases where the fuel is reprocessed, the uranium is recycled through the diffusion plant, and the recovered plutonium-239 may be used in place of some uranium-235 in new fuel elements.
3. What do you understand by the term “deforestation”? Discuss its ill-effects on the mankind.
Deforestation: is a large-scale removal of forest prior to its replacement by other land uses. Forests are removed for a variety of reasons, including agriculture, timber harvesting, and mining, and to make way for roads, dams, and human settlements.
Deforestation poses a severe worldwide environmental problem. Forests take enormous amounts of carbon dioxide from the atmosphere in the process of photosynthesis. The destruction of forests exacerbates the accumulation of carbon dioxide in the atmosphere, which then contributes to global warming. In addition, deforestation causes soil erosion and destabilizes watersheds, resulting in flooding or drought.
Deforestation also reduces biodiversity, particularly significant in tropical forests that are home to a substantial portion of the world’s plant and animal species. Deforestation processes are, in general, more destructive in the tropics. Most forest soils in the tropics are far less fertile than temperate soils, and more vulnerable to erosion. This is due to high rainfall, which leaches nutrients from the soil and speeds erosion.
4. Fill in the blanks.
a) The largest planet of the solar system is
Jupiter.
b) The outermost layer of the earth is called
crust.
c) Newton is the unit of
force.
d) Radium was discovered by
Madam Curie.
e) The memory of the computer is expressed in
bytes.
f) Quartz is a crystalline form of
silicon dioxide.
g) AIDS is caused by
Human Immune Deficiency Virus (HIV).
h) Chemical name of gypsum is
Calcium Sulfate.
i) Molten super hot material present inside a volcano is called
magma.
j) Richter scale measures the severity of
earth quake.
6. Write short notes (not more than 150 words) on any two of the following.
a) Semi-conductors
b) Pesticides
c) Laser.
Answers:
a) Semi-conductors:
Semiconductor, solid or liquid material, able to conduct electricity at room temperature more readily than an insulator, but less easily than a metal.
Such metals as copper, silver, and aluminum are excellent conductors, but such insulators as diamond and glass are very poor conductors .At low temperatures, pure semiconductors behave like insulators. Under higher temperatures or light or with the addition of impurities, however, the conductivity of semiconductors can be increased dramatically, reaching levels that may approach those of metals.
b) Pesticides: a chemical substance used to kill pests, especially insects. The chemical agents called pesticides include herbicides (for weed control), insecticides, and fungicides.
c) Laser: a device that produces and amplifies light. The word laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Laser light is very pure in color, can be extremely intense, and can be directed with great accuracy. Lasers are used in many modern technological devices including bar code readers, compact disc (CD) players, and laser printers. Lasers can generate light beyond the range visible to the human eye, from the infrared through the X-ray range. Masers are similar devices that produce and amplify microwaves.
10. Classify the following animals are reptiles, mammals, birds and fish.
Answers:
a) Blue whale----
Mammals
b) Cobra--------
Reptile
c) Panda--------
Mammal
d) Ostrich-------
Bird
e) Penguin------
Bird
f) Kiwi----------
Bird
g) Shark--------
Fish
h) Alligator -----
Reptile
i) Dolphin-------
Mammal
j) Tortoise------
Reptile
12. Differentiate between the following.
a) Hypoglycemia and hyperglycemia
b) Epidemic and endemic
c) Herbivores and carnivores
d) Photosynthesis and respiration
e) Pollination and fertilization
Answers:
a) Hypoglycemia and Hyperglycemia:
Hypoglycemia:the medical condition of having an unusually low level of sugar in the blood
Hyperglycemia: the medical condition of having an unusually high level of sugar in the blood
b) Epidemic and Endemic
Epidemic: outbreak of contagious disease affecting an unusually large number of people or involving an extensive geographical area.
Endemic:a disease that usually occurrs within a particular area or locality some time in a year.
c) Herbivores and carnivores
Herbivore, animal that eats only plant material. Herbivores are primary consumers in the food web.
Carnivore, general term for any animal that subsists mainly on the flesh of other animals
d) Photosynthesis and respiration:
Photosynthesis: process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose.An extremely important byproduct of photosynthesis is oxygen, on which most organisms depend.
Respiration: Here we take oxygen and exhale carbon dioxide where as in plants in day time co2 is taken and o2 is given off.
e) Pollination and fertilization:
Pollination: transfer of pollen grains from the male structure of a plant to the female structure of a plant. The pollen grains contain cells that will develop into male sex cells, or sperm. The female structure of a plant contains the female sex cells, or eggs. Pollination prepares the plant for fertilization, the union of the male and female sex cells. Virtually all grains, fruits, vegetables, wildflowers, and trees must be pollinated and fertilized to produce seed or fruit, and pollination is vital for the production of critically important agricultural crops, including corn, wheat, rice, apples, oranges, tomatoes, and squash.
Fertilization: the process in which gametes—a male's sperm and a female's egg or ovum—fuse together, producing a single cell that develops into an adult organism. Fertilization occurs in both plants and animals that reproduce sexually—that is, when a male and a female are needed to produce an offspring.
14. Fill in the blanks with the correct choice.
a) pH of blood is (3.4-4.4,
7.3-7.4, 9.3-9.4)
b) One of the countries through which equator passes is (
Kenya, Pakistan, Malaysia)
c) Purest form of iron is (pig iron,
wrought iron, cast iron)
d) Hypo is a solution of (sodium chloride, silver nitrate,
sodium thiosulphate)
e) Cod liver oil contains (Vitamin K, Vitamin E,
Vitamin D)
f) Aorta is an organ of the (nervous system,
circulatory system, digestive system)
g) Planet Mars has (one,
two, four) moons.
h) Bauxite is an ore of (boron,
aluminum, magnesium).
i) Circular aperture which appears as a dark spot in the eye is called (iris,
pupil, lens)
j) The most distant planet in the solar system is (mars,
Pluto, Jupiter)
15. Match the scientists and their discoveries/inventions given in column (a) and (b):
....A….................…B
Einstein…........…Neutron
Roentgen…........Laws of heredity
Charles Darwin….X-Rays
Chadwick……...…Theory of evolution
Mendel…….........Mass energy conversion equation
Answers:
....A…................…..B
Einstein…..........Mass energy conversion equation
Roentgen........…X-rays
Charles Darwin...Theory of evolution
Chadwick……......Neutron
Mendel…...........Laws of hereditary
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