(a) In a forest the steps of food chain:
Trees (producers)- Deer (primary consumer)- Lion (top consumer)
(b) In grassland the steps of food chain
Grasses (producers)- rabbit (primary consumers)- Snake (secondary consumer)- owl (top consumer)
(c) In a pond the steps of food chain
Algae and aquatic plants (producers)- small fish (primary consumers)- big fish (secondary consumer)- shark (top consumer)