How does sexual reproduction contribute to genetic diversity in a population?

Sexual reproduction contributes to genetic diversity by combining genes from two parents to create unique offspring.

Sexual reproduction is a biological process that involves the combination of genetic material from two parents to produce offspring. This process is crucial in promoting genetic diversity within a population. Genetic diversity refers to the total number of genetic characteristics in the genetic makeup of a species. It is the variation in the genetic composition of a population that allows for adaptation and evolution.

The first step in sexual reproduction is meiosis, a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell. During meiosis, genetic material is shuffled in a process called recombination or crossing over. This is where homologous chromosomes - one from each parent - pair up and exchange segments of DNA. This shuffling of genes creates new combinations of traits that may not have existed in either parent, contributing to genetic diversity.

Fertilisation is the next step, where the sperm and egg cells combine to form a zygote. Each parent contributes half of the genetic material for the new organism. The combination of these two sets of genes results in a unique individual with a genetic makeup different from both parents. This process of random fertilisation further increases genetic diversity as it produces a wide range of possible gene combinations in the offspring.

Moreover, sexual reproduction allows for natural selection to occur. Natural selection is the process by which individuals with traits that are advantageous for their environment are more likely to survive and reproduce. This means that the genes associated with these beneficial traits are more likely to be passed on to the next generation. Over time, this can lead to changes in the genetic makeup of a population, further contributing to genetic diversity.

In conclusion, sexual reproduction plays a vital role in promoting genetic diversity. Through processes such as meiosis, fertilisation, and natural selection, it allows for the creation of unique individuals and the evolution of populations over time.