“Detritus food chain may be connected with the grazing food chain at some levels”.  This is evident from

i:	Some of the organisms of DFC are prey to the GFC animals
ii:	In a natural ecosystem, some animals like cockroaches, crows, etc., are omnivores.
iii:	Some of the organisms of GFC are facultative decomposers

1. i and iii

2. i and ii

3. ii and iii

4. i only

What do you mean by a food web?

1. Group of food chains.

2. Food chains present in a particular area

3. Natural interconnection of food chains

4. Food chains formed by members of a genus

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

What do you mean by the standing crop?

1. Crop in a field at a given time

2. Each trophic level has a certain mass of living material at a particular time.

3. Each trophic level has a certain mass of organic material at a particular time.

4. Top trophic level has a certain mass of organic material at a particular time.

The standing crop is measured as the-

1. Mass of living organisms in a unit area.

2. The number of living organisms in a unit area.

3. Calculated from the net primary productivity

4. Both 1 and 2.

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.

What does 10 per cent law say?

The base of each pyramid represents the _________or the ___________level while the apex represents ____________
1. Consumers, first trophic and top trophic level
2. Producers, first trophic and top trophic level
3. Producers, second trophic and top trophic level
4. Consumers, second trophic and top trophic level

Identify the relationship represented by the pyramid

1. Pyramid of number

2. Pyramid of biomass

3. Pyramid of energy

4. None of the above

Which of the following pyramid represents the pyramid of number in grassland?

                          A

                        B

                          C

1. A

2. B

3. C

4. B & C