Question

In the wild, various sperm and egg cells must navigate a complex environment to complete fertilization. There are mechanisms in place at the molecular level to guard against interspecies fertilization, even between very closely related species. Some of these mechanisms involve lock and key functions of interacting proteins. These molecules most likely regulate which type of reproductive isolation mechanism? Please explain.

Describe an example of non-heritable variation. Think about the way an organism interacts with its environment and how that influences its phenotype (the nurture in nature vs. nurture). Knowing what you do about genetics, genes, and gene expression control, propose a mechanism of molecular control that might be working in the example you have chosen.

Answer 1

The mechanical mechanisms of reproductive isolation involve the lock and key mechanism. In such methods, the incompatibility of the sperm and eggs at the molecular level prevents them for fertilizing and producing a zygote. The proteins produced by the eggs and sperms belonging to two different species are different which prevent the sperm from entering the egg cell.