How does sexual reproduction contribute to genetic diversity?

Sexual reproduction contributes to genetic diversity through the processes of meiosis and fertilisation.

Sexual reproduction involves the fusion of two gametes, each carrying genetic information from one parent. This process is known as fertilisation. The offspring produced as a result of sexual reproduction inherit a unique combination of genes from both parents, which contributes to genetic diversity.

The process of meiosis, which produces the gametes, is another key contributor to genetic diversity. During meiosis, chromosomes pair up and exchange segments of DNA in a process called crossing over. This results in new combinations of genes on each chromosome. Additionally, the way the chromosomes line up during meiosis is random, leading to different combinations of chromosomes in each gamete. This is known as independent assortment.

The combination of crossing over and independent assortment during meiosis, along with the fusion of two different gametes during fertilisation, results in offspring with a unique genetic makeup. This genetic variation is the basis of genetic diversity.

Genetic diversity is crucial for the survival and evolution of species. It provides a buffer against environmental changes and diseases, as some individuals within a population may have the genetic traits necessary to survive these challenges. Furthermore, genetic diversity can lead to new traits that may be beneficial for the survival of the species.

In summary, sexual reproduction, through the processes of meiosis and fertilisation, introduces new combinations of genes in the offspring. This results in genetic diversity, which is vital for the survival and evolution of species.