megtermékenítés

Megtermékenyítés, commonly referred to as fertilization, is the biological process by which a male gamete (sperm) fuses with a female gamete (egg) to form a new single cell, the zygote. This fusion is a critical step in sexual reproduction, initiating the development of a new organism.

In animals, fertilization typically occurs internally or externally. Internal fertilization involves the deposition of sperm directly into the female reproductive tract, as seen in mammals, birds, and reptiles. External fertilization, on the other hand, occurs outside the body, with both sperm and eggs released into the environment, often in aquatic settings, such as with many fish and amphibians.

In plants, fertilization involves the transfer of pollen, containing male gametes, to the female reproductive part of a flower, the pistil. This transfer can be facilitated by wind, water, insects, or other animals. Once the pollen reaches the stigma, it germinates and grows a pollen tube down to the ovule, where fertilization takes place.

The process of fertilization is highly regulated and involves specific molecular interactions to ensure that only a compatible sperm fuses with the egg. Once the zygote is formed, it undergoes a series of cell divisions and differentiation, leading to the development of an embryo and eventually a complete organism. Fertilization is a fundamental event that perpetuates species by combining genetic material from two parents, leading to genetic diversity.