What is the process of fertilization in sexual reproduction?

Fertilisation in sexual reproduction is the fusion of male and female gametes to form a zygote.

In more detail, sexual reproduction involves the combination of genetic material from two parent organisms to produce offspring that are genetically different from their parents. This process begins with the formation of gametes, or sex cells, in the parent organisms. In males, these are sperm cells, and in females, they are egg cells. These gametes are produced through a process called meiosis, which results in cells with half the number of chromosomes of a normal cell.

Fertilisation occurs when a sperm cell from the male parent fuses with an egg cell from the female parent. This fusion results in a single cell called a zygote, which contains a complete set of chromosomes - half from each parent. This process is also known as syngamy.

The zygote then begins to divide and grow into an embryo through a process called mitosis, where each cell divides to produce two identical cells. As the embryo develops, these cells differentiate into different types of cells, forming the various tissues and organs of the offspring.

The process of fertilisation ensures the continuation of genetic variation within a species, as each offspring is genetically unique. This genetic diversity is crucial for the survival and evolution of species, as it allows for adaptation to changing environments.

In summary, fertilisation in sexual reproduction is a complex process involving the fusion of male and female gametes to form a zygote, which then develops into an embryo. This process is fundamental to the continuation of life and the evolution of species.