Question

B. Give a single term for each of the following sentences.
1.
A situation or condition in which an organism lives.
2. The only planet in our solar system where life exists.
3.
The uppermost part of the lithosphere which is rich in silica and aluminium.
4.
The sphere of air that envelopes the earth.
5.
Mass of water on the earth's surface.​

Answer 1

$<font color= red>$ 1.Question:

$<font color= black>$ A situation or condition in which an organism lives.

$<font color= blue>$ Answer:

$<font color= black>$

Habitat

$<font color= red>$ 2.Question :

$<font color= black>$ The only planet in our solar system where life exists.

$<font color= blue>$ Answer :

$<font color= black>$ Earth

$<font color= red>$ 3. Question:

$<font color= black>$ The uppermost part of the lithosphere which is rich in silica and aluminium.

$<font color= blue>$ Answer :

$<font color= black>$ The uppermost layer of the crust is called sial consisting of silicate and Aluminium (Si =silicate, Al= aluminium).

$<font color= red>$ 4. Question :

$<font color= black>$ The sphere of air that envelopes the earth.

$<font color= blue>$ Answer :

$<font color= black>$ Atmosphere

$<font color= red>$ 5.Question:

$<font color= black>$ Mass of water on the earth's surface.

$<font color= blue>$ Answer :

$<font color= black>$ About 71 percent

Answer 2

Single terms for questions are -

1. A situation or condition in which an organism lives.

Habitat.

Habitat is the natural environment which is suitable for organism to live, due to availability of required resources. Example - desert, aquatic system.

2. The only planet in our solar system where life exists.

Earth. Solar system comprises of large number of galaxies. Out of them milky way galaxy has the habitable planet namely earth.

3.The uppermost part of the lithosphere which is rich in silica and aluminium.

Sial. Thickness of sial is approximately 25 km.

4. The sphere of air that envelopes the earth.

Atmosphere. Biosphere comprises of three spheres namely lithosphere, hydrosphere and atmosphere.

Lithosphere deals with land, hydrosphere refers to water and atmosphere contains air.

5. Mass of water on the earth's surface.​

Earth is known to contains 71% water. Which can be translated to 1.4 × 10^18 tonnes of water.