EVERYDAY SCIENCE

Detailed explanation-1: -Definition. Crossing over, as related to genetics and genomics, refers to the exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis).

Detailed explanation-2: -During the metaphase of meiosis, there is exchange of chromatid parts between the maternal and the paternal chromatids of a pair of homologous chromosomes during meiosis. This phenomenon is known as crossing over. The site at which the genetic material is exchanged is called as chiasmata.

Detailed explanation-3: -When recombination occurs during meiosis, the cell’s homologous chromosomes line up extremely close to one another. Then, the DNA strand within each chromosome breaks in the exact same location, leaving two free ends. Each end then crosses over into the other chromosome and forms a connection called a chiasma.

Detailed explanation-4: -An exchange of chromosome segments between non-sister homologous chromatids occurs and is called crossing over. The crossover events are the first source of genetic variation produced by meiosis.

Detailed explanation-5: -Crossing-over is the exchange of genetic material between homologous chromosomes. It results in new combinations of genes on each chromosome. When cells divide during meiosis, homologous chromosomes are randomly distributed to daughter cells, and different chromosomes segregate independently of each other.