Page 2 - 3- Home Assignment I (Obj & Subj)-Mineral riches in the soil

(b) Diamond
(c) Silica
(d) Gypsum
10 This mineral is used in electric bulbs.
(a) Gypsum
(b) Calcium
(c) Tungsten
(d) Graphite

Subjective

1. How can we prevent the loss of topsoil? 1 E
2. Soil formation is done by both abiotic and biotic factors. List the names 1 E
of these factors by classifying them as abiotic and biotic?
3. Lichens are called pioneer colonizers of bare rock. How can they help in 1 Av
the formation of soil?
4. “Soil is formed by water.” If you agree to this statement then give reasons 3 Av
5. Fertile soil has lots of humus. Why? 3 D
6. Write the composition of soil. On what basis is the type of soil decided? 3 D