Formation of fertilization cone in egg? And prevention of polyspermy? And Amphimixis?

The formation of a fertilization cone in an egg occurs during the process of fertilization in certain organisms, such as sea urchins. When a sperm approaches the egg, it releases enzymes that help it penetrate the egg's protective layers. This triggers a series of changes in the egg's membrane, causing it to extend outward and form a cone-like structure called the fertilization cone. The sperm then enters the egg through this cone, allowing for the fusion of their genetic material.

Polyspermy refers to the entry of multiple sperm into an egg, which can be detrimental to the development of the embryo. To prevent polyspermy, organisms have evolved various mechanisms. One common mechanism is the formation of a fertilization membrane or a zona pellucida, which hardens after the entry of the first sperm, blocking the entry of additional sperm. Additionally, the egg may release substances that repel or inactivate any remaining sperm in the vicinity.

Amphimixis refers to the process of sexual reproduction, specifically the fusion of two gametes (sperm and egg) to form a zygote. It involves the combination of genetic material from both parents, resulting in genetic diversity in offspring. Amphimixis is a fundamental process in sexual reproduction, allowing for the shuffling and recombination of genetic material, which contributes to the variation and adaptability of species.