Question

Sexual reproduction promotes genetic variation. One way variation occurs is via the production of gametes during meiosis. Sexual organisms are the product of sperm and egg, receiving chromosomes from both parents. But what mechanisms are at work during meiosis to promote genetic variation?

Answer 1

Meiosis is a special type of cell division where the cell undergoes two rounds of cell division to produce four daughter cells, each with half the number of chromosomes of the original parent cell and with unique set of genetic material as a result of exchange of chromosome segment during the process of crossing over.

Step-by-step explanation:

Crossing over takes place during Pachytene, a sub-stage of Prophase I where a segment of a sister chromatid of one chromosome is exchanged with the same segment of the sister chromatid of the homologous chromosomes through the formation of a cross-linkage of the segments called chiasma (see attach picture). After crossing over, the sister chromatids of each chromosome is no longer identical with each other based on the genetic material that they contain, hence genetic variation occurs.