How many of the following organisms are decomposers in a pond ecosystem?
Some algae,fungi,bacteria,floating plants,submerged plants,flagellates.

As insecticides reach at higher trophic level in food chain,their concentration:

Which of the following statements are correct regarding a food chain?
$(a)$ If $80\%$ of tigers are removed from an area,the growth of vegetation in that area increases.
$(b)$ If carnivores are removed from an area,the population growth of deer increases.
$(c)$ The length of a food chain is limited to $3$ to $4$ trophic levels because the amount of energy decreases in the ecosystem.
$(d)$ The length of a food chain is usually $2$ to $8$ trophic levels.

What type of food chain is the following?
Grass $\rightarrow$ Goat $\rightarrow$ Human

If all the plants of the world die,all the animals will also die due to the shortage of:

Pisaster is a . . . . . . .