Page 2 - 3- Home Assignment I (Obj & Subj)- Bio- geo chemical cycles-1

(b) Animals
(c) Microorganisms
(d) Water
10 All rocks are made up of:
(a) Metals
(b) Salt
(c) Iron
(d) Minerals

Subjective

1. What are the main substances of biogeochemical cycles? 1 E
2. Which group of plants contains nitrogen fixing bacteria in their roots? 1 E
Where these bacteria found in the plant body?
3. State the role of symbiotic bacteria in nitrogen cycle of nature. 1 Av
4. What is meant by water cycle? How are nutrients from land made 3 Av
available to marine organisms by this cycle?
5. Why nitrogen cycle is called perfect cycle in biosphere? 3 D
6. Draw well-labelled diagram to show nitrogen cycle in nature. 3 D