Explain the concept of trophic level in an ecosystem.

Explain Grazing food chain with example.

Bring out the significance of food web.

Spindle shaped pyramid of number is noticed in forest ecosystem. Give reasons.

Frame any two food chain patterns from the given organisms. Each chain must contain a minimum of four organisms.
Diatoms, Hawk, Rabbit, Vallisneria
Stoke, guppies, grass, snake, large fishes, grasshopper, crane.