Biochemical recognition systems on the surface of an egg cel

Biochemical recognition systems on the surface of an egg cell prevents the sperm from a closely related species from being able to fuse and create a zygote. This is an example of what kind of reproductive isolation?

Question 8 options:

pre-zygotic, gametic

post-zygotic, genetic incompatibility

pre-zygotic, mechanical

post-zygotic, gametic

Solution

ANS: a. pre-zygotic, gametic

Pre-zygotic barriers prevent animals from mating or, if mating occurs, prevent the sperm from fertilizing the egg.

Post-zygotic barriers are the barriers that occurs after fertilization.

Gametic isolation: In this animals come into contact, but the gametes (reproductive cells) are not compatible.

It is a Pre-zygotic barriers. The egg and sperm is released but the zygote is not formed. It is because of the sperm and egg had specific proteins on their surfaces that allows sperm to recognize the egg vice-versa, and these proteins are differ from species to species.

According to this question (Biochemical recognition systems on the surface of an egg cell prevents the sperm from a closely related species from being able to fuse and create a zygote) it is clearly indicating before fertilization, so it is pre-zygotic.

In Pre-zygotic mechanical condition individuals cannot mate due to physical incompatibilities.