Choose the correct set of answers from the following: I. Frogs are bioindicators II. Frogs are biological control agents III. Frogs play an important role in the food web
I and II
I, II and III
I and III
II and III
The correct option is B I, II and III Frogs are sensitive to environmental changes such as pollution. One reason for this could be the permeable skin that can absorb toxins and pollutants. This can cause malformations in frogs. Hence frogs act as bioindicators. A decline in amphibian population can be an indicator of pollution. Frogs act as biological control agents by protecting the crops. It feeds on harmful insects. They have an important role in the food chains and food webs. Hence they help in maintaining the balance of the ecosystem.