(a) Differentiate between grazing food chain and detritus food chain.

• Brood parasitism is a method of parasitism in which the parasitic bird lays its eggs in the nest of the host bird and let the host bird to incubate them.

• Example – The cuckoo bird lays its eggs in the nest of crow , egg of cuckoo bird resembles crows’ egg in size and colour to reduce the chance of host bird detecting and ejecting them from nest

Grazing Food Chain

Detritus Food Chain

1. It starts with producers.

Starts from dead organic

matter/ detritus

2. 2nd trophic level is occupied

by herbivores.

2nd trophic level is occupied by detritivores.

3. In aquatic ecosystem a major

fraction of energy flows

through this type of food

chain

In terrestrial ecosystem much

larger fraction of energy flow through such type of food chain.