Which of the following statements best describes the significance of meiosis in human sexual reproduction?
Meiosis is the process of cell division that occurs in the reproductive cells (gametes) of humans. It is significant in human sexual reproduction due to the following reasons:
1. Genetic Variation: Meiosis allows for the random assortment and recombination of genetic material, leading to the production of genetically diverse offspring. This genetic variation is essential for evolution and adaptation to changing environments.
2. Halving of Chromosome Number: Meiosis reduces the chromosome number by half in the gametes, ensuring that when fertilization occurs, the resulting zygote will have the correct number of chromosomes (46 in humans). Without meiosis, the offspring would inherit a doubling of the chromosomes with each generation.
3. Sexual Reproduction: Meiosis is responsible for the formation of both male and female gametes (sperm and eggs), which combine during fertilization to create a genetically unique individual. This process allows for the mixing of genetic material from two individuals, promoting diversity within a population.
4. Genetic Recombination: Meiosis allows for the exchange of genetic material between homologous chromosomes through a process called crossing-over. This recombination creates new combinations of genes, further increasing genetic diversity in offspring.
In summary, meiosis plays a vital role in human sexual reproduction by generating genetic diversity, ensuring the correct chromosome number, and enabling the formation of gametes.