Energy flow in an ecosystem is 

(1) unidirectional

(2) bidirectional

(3) multi-directional

(4) All the these 

Which are the primary consumers in a grazing food chain?

1. Carnivores

2. Herbivores

3. Detrivores

4. Omnivores

Of the total incident solar radiation the proportion of PAR is 

1. about 60%

2. less than 50%

3. more than 80%

4. about 70%

What does 10 per cent law say?

Based on the source of organism’s nutrition or food, they occupy a specific place in the food chain that is known as-

1. Strata

2. Trophic level

3. Sere

4. Chain level

The second trophic level in a lake is:

1. Phytoplankton

2. Zooplankton

3. Benthos

4. Fishes

Why does the number of trophic levels in the grazing food chain is restricted ?

1. As the transfer of energy follows 10 per cent law

2. So that food chain remains short

3. As there are few species the community

4. So that transfer of energy could be more efficient.

Consider the following statements:

Which of the above statements are true?

Which trophic level is incorrectly defined?
1. Carnivores- secondary or tertiary consumer
2. Decomposer- microbial heterotrophs
3. Herbivores - primary consumer
4. Omnivores - Molds, yeast and mushrooms

What do secondary carnivores refer to?

1. Animals at second trophic level

2. Those animals that depend on the herbivores for food

3. Those animals that depend on the primary carnivores for food

4. Those animals that depend on the secondary herbivores for food