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Botany - Ecosystem Book Back Questions

12th Standard EM

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Biology

Time : 00:45:00 Hrs
Total Marks : 30
5 x 1 = 5
1. Profundal zone is predominated by heterotrophs in a pond ecosystem, because of

(a)

with effective light penetration

(b)

no effective light penetration

(c)

complete absence of light

(d)

a and b

2. Solar energy used by green plants for photosynthesis is only

(a)

2 – 8%

(b)

2 – 10%

(c)

3 – 10%

(d)

2 – 9%

3. Which of the following ecosystem has the highest primary productivity?

(a)

Pond ecosystem

(b)

Lake ecosystem

(c)

Grassland ecosystem

(d)

Forest ecosystem

4. Which one is in descending order of a food chain

(a)

Producers $\rightarrow$ Secondary consumers $\rightarrow$ Primary consumers $\rightarrow$ Tertiary consumers

(b)

Tertiary consumers $\rightarrow$ Primary consumers $\rightarrow$Secondary consumers $\rightarrow$ Producers

(c)

Tertiary consumers $\rightarrow$ Secondary consumers $\rightarrow$ Primary consumers $\rightarrow$ Producers

(d)

Tertiary consumers $\rightarrow$ Producers $\rightarrow$ Primary consumers $\rightarrow$ Secondary consumers

5. Significance of food web is / are

(a)

it does not maintain stability in nature

(b)

it shows patterns of energy transfer

(c)

it explains species interaction

(d)

b and c

6. 3 x 2 = 6
7. Discuss the gross primary productivity is more efficient than net primary productivity.

8. Pyramid of energy is always upright. Give reasons

9. What will happen if all producers are removed from ecosystem?

10. 3 x 3 = 9
11. Construct the food chain with the following data.
Hawk, plants, frog, snake, grasshopper.

12. Shape of pyramid in a particular ecosystem is always different in shape. Explain with example.

13. Generally human activities are against to the ecosystem, where as you a student how will you help to protect ecosystem?

14. 2 x 5 = 10
15. Draw a pyramid from following details and explain in brief.
Quantities of organisms are given-Hawks-50, plants-1000.rabbit and mouse-250 +250, pythons and lizard- 100 + 50 respectively.

16. Various stages of succession are given bellow. From that rearrange them accordingly. Find out the type of succession and explain in detail.
Reed-swamp stage, phytoplankton stage, shrub stage, submerged plant stage, forest stage, submerged free floating stage, marsh medow stage.