Question

What is the function of copulatory pads in the forelimbs of frogs?

Answer 1

Hint: Copulatory pads also called thumb pads are usually present in the forelimbs of male frogs only. This helps the mail frog to hold the female frog tightly underneath its body during copulation.

Complete answer:
Fertilization is of two types external (fertilization or formation of zygote outside the body as in fishes) and internal (fertilization or formation of zygote inside the body as in mammals).
 Frogs usually undergo false copulation as no copulatory organs are inserted inside the body of the female frog. Males attract females with their voice. When the female approaches the male, it starts to ride on the back of the female frog and rides along it by pressing the abdomen of the female with a copulatory pad and hence the female releases her egg in the water. Males shed their sperm on it and hence fertilization occurs outside the body.
These copulatory organs are present on the first digit of the hindlimb. Which helps in holding and pressing the female body to release eggs.

Note:
Copulatory pads or thumb pads are adhesive flap-like structures present in the forelimbs of male frogs only, this helps in identification or differentiation in both the sexes.