Ecosystem

Q.1: Vertical distribution of different species occupying different levels is called _______________.

a) interaction

b) stratification

c) enumeration

Q.2: ________________ of an ecosystem is the rate of production of organic matter during photosynthesis.

a) productivity

b) secondary productivity

c) gross primary productivity

Q.3: Net primary productivity is the biomass for the consumption to ______________.

a) autotrophs

b) heterotrophs

c) both

Q.4: Which of the following is not an important step in the process of decomposition ?

a) catabolism

b) leaching

c) productivity

Q.5: In ______________ process, the humus is degraded by some microbes and release the inorganic nutrients.

a) mineralisation

b) fragmentation

c) humification

Q.6: The decomposition rate is ____________, if detritus is rich in lignin and chitin.

a) slower

b) faster

c) normal

Q.7: Which of the following belongs to the third trophic level ?

a) phytoplankton, grass

b) man, lion

c) birds, fish

Q.8: To obtain the Net Primary Productivity, we have to minus respiration losses from ___________________.

a) secondary productivity

b) gross primary productivity

c) both

Q.9: Each trophic level has a certain mass of living material at a particular time called as the _________________.

a) Standing Crop

b) Sere

c) Standing state

Q.10: Which of the following statements is/are true about Nutrient cycling ?

a) The other name of nutrient cycling is ‘biogeochemical’ cycles.

b) Nutrient cycling is of three types.

c) Both

Q.11: ____________ succession takes place in dry areas.

a) mesic

b) hydrarch

c) xerarch

Q.12: ___________________ is a major constituent of biological membranes, nucleic acids and cellular energy transfer systems.

a) carbon

b) phosphorous

c) nitrogen

Q.13: According to an estimation, ______________ of carbon is fixed annually in the biosphere through photosynthesis.

a) 4 x 10¹³ kg

b) 3 x 10¹⁴ kg

c) 4 x 10¹⁴ kg

Q.14: Why is the secondary succession faster than the primary succession ?

a) Because of the presence of the vegetation.

b) Because of the presence of the soil or sediment.

c) Because of the presence of the climatic conditions.

Q.15: Phosphorous cycle is an example of ____________ cycle.

a) gaseous

b) sedimenatary

c) none

Q.16: The entire sequence of communities that successively change in a given area are called __________.

a) seres

b) climax

c) pioneer

Q.17: _______________ are not given any place in ecological pyramids.

a) herbivores

b) producers

c) saprophytes

Q.18: ______ % of the photosynthetically active radiation is captured by the green plants.

a) 2-5

b) 10-20

c) 2-10

Answers:

1. b
2. c
3. b
4. c
5. a
6. a
7. c
8. b
9. a
10. a
11. b
12. b
13. a
14. b
15. b
16. a
17. c
18. c