Originally Posted by Xeric

4. Attempt any five of the following

(a) The solar system has:

(i) 9 planets
(ii) 12 planets
(iii) 16 planets

Ans. Now there are 8 major and several dwarf planets.


(b) The science of study of old age is called:

(i) Gerontology
(ii) Carcinology
(iii) Nephrology

Ans. (i) Gerontology


(c) The instrument used for measuring the velocity of air:

(i) Barometer
(ii) Anemometer
(iii) Potometer

Ans. (ii) Anemometer


(d) The science which deals with the bird is called:

(i) Entomology
(ii) Ornithology
(iii) Herpetology

Ans. (ii) Ornithology


(e) The function of the thermostat in a refrigerator is:

(i) To increase the freezing point
(ii) To Lower the temperature
(iii) To maintain the temperature

Ans. (iii) To maintain the temperature


(f) Blotting paper absorbs ink because:

(i) It has a chemical affinity for ink
(ii) The action of capillary
(iii) The force of gravitation acts between blotting paper and ink.

Ans. (ii) The action of capillary


(g) Mirage is an example of:

(i) Reflection of light
(ii) Refraction and internal reflection of light
(iii) Polarization of light

Ans. (i) Reflection of light



6. Where are the following animals found? Answer any five.

a) Kangaroo
b) Kiwi
c) Llama
d) Ibex
e) Panda
f) Snow Leopard
g) Penguin

Answer:

a) Australia
b) New Zealand
c) South America
d) Himalaya, Abyssinia
e) North India
f) Central Asian Mountains
g) Cooler waters and along the coastlines in Southern Hemisphere


7. Name the sources of any five of the following biological products.

a) Musk
b) Codeine
c) Cocaine
d) Quinine
e) Colchicines
f) Digilain

Answer:

a) Abdominal gland of male musk deer
b) From opium
c) Cocaine
d) Bark of cinchona
e) From colchicum
f) Leaves from the purple foxglove; a plant


9. Differentiate between any five of the following:

a) DNA and RNA
b) Alloy and Amalgam
c) Blood and Lymph
d) Stars and Planets
e) Gas and Vapour
f) Brass and Bronze


Answers:

a) DNA & RNA

RNA:

It is single stranded molecule
Contains Ribose sugar
contains adanine, guanine ,cytosine, & uracil bases
generally located in cytoplasm
is of three kinds

DNA:

Double stranded
deoxyribose
contains adanine, guanine cytosine and thymine bases
is of one kind


b) Alloy and Amalgam:

Alloy:

Substance composed of two or more metals. Alloys, like pure metals, possess metallic luster and conduct heat and electricity well, although not generally as well as do the pure metals of which they are formed. Compounds that contain both a metal or metals and certain nonmetals, particularly those containing carbon, are also called alloys. The most important of these is steel. Simple carbon steels consist of about 0.5 percent manganese and up to 0.8 percent carbon, with the remaining material being iron.

Amalgam:

Amalgam is an alloy of mercury with one or more metals.


d) Stars and Planets:

Stars:

Heavenly bodies that shine by its own light and remains relatively fixed in position among the other bodies in the universe.light and energy is generated in a star by the conversion of hydrogen into helium.

Planet:

Opaque bodies revolving around the sun in its own orbit & also rotating on its own axis, shines by reflection of the light of other stars( such as sun).


e) Gas and Vapour:

The terms vapor and gas can be used interchangeably, although in practice, vapor is used for a substance that is normally in liquid or solid state, such as water, benzene, and iodine. It has been proposed that the use of the term vapor be restricted to a gaseous substance below its critical point; the temperature at which it may be liquefied by the application of sufficient pressure) and the term gas should be used above the critical temperature when the existence of the substance in the liquid or solid state is impossible. This usage is essentially arbitrary because all gaseous substances follow a similar behavior both above and below the critical point.


f) Brass and Bronze:

Brass: an alloy of copper and zinc
Bronze: an alloy of copper and tin


13. Name two diseases caused by following groups of micro-organisms.

a) Bacteria
b) Viruses
c) Protozoa
d) Fungi

Answers:

a) Tuberculosis, Typhoid, Cholera
b) Poliomyelitis, Influenza
c) Sleeping sickness, Amoebic dysentery
d) Ringworm, Actinomycosis