Question

Give reason: Organisms exhibiting external fertilization show great synchrony between the sexes and release a large number of gametes into the surrounding medium.

Answer 1

External fertilization is a process in which, male and female gametes are released outside their bodies and male and female gametes are fused with each other in the outside medium, this is called as external fertilization.

Complete answer:
External fertilization is a mode of reproduction in which, male and female individuals release their gametes in the open environment or medium where fusion of male gamete and female gamete take place, this whole process is known as external fertilization.

The amount of male and female gametes produced is very high because chances of mating or fusion is very less and gametes may be destroyed, may be eaten by some other species, washed away with the flow of water or maybe get damaged. Plus, for successful fusion of gametes, male and female organisms should release the gametes at same time with great synchrony.

There are many organisms which fertilize through external fertilization methods like salmon, cod, trout and char are some fishes, which fertilize through external fertilization. Frogs, toads, anurans, salamanders and newts are some amphibians that reproduce through external fertilization.

Thus, we can conclude that organisms that reproduce through external fertilization exhibit greater synchrony and release large numbers of male and female gametes for successful fertilization as the chances of fertilization is low.

Note: In internal fertilization, insemination takes place which helps in the movement of sperms to the egg and sperms fuse with eggs inside the female’s body. But in case of external fertilization, sperms and eggs are released in some water bodies or in moisture conditions to facilitate the movement of sperms to the egg.