Which of the following processes is essential for sexual reproduction?

Meiosis is the key process involved in sexual reproduction, as it is responsible for producing gametes—sperm and eggs—in organisms that reproduce sexually. This process reduces the chromosome number by half, ensuring that when two gametes fuse during fertilization, the resulting offspring have the appropriate diploid number of chromosomes. This genetic recombination during meiosis also promotes genetic diversity in a population, which is crucial for evolution and adaptation.

In contrast to meiosis, mitosis is primarily involved in growth, development, and asexual reproduction, leading to the generation of somatic cells without changing the chromosome number. Asexual reproduction does not involve gametes and can occur through mechanisms like budding or binary fission, bypassing the need for meiotic processes entirely. Ploidy refers to the number of sets of chromosomes in a cell and while it is a relevant concept in understanding sexual reproduction and the outcomes of meiosis, it does not itself represent a process. Thus, meiosis is essential for producing the genetic variability and haploid cells necessary for the formation of new individuals through sexual reproduction.