AP BIOLOGY

Detailed explanation-1: -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: -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-3: -Chromosomal crossover, or crossing over, is the exchange of genetic material during sexual reproduction between two homologous chromosomes’ non-sister chromatids that results in recombinant chromosomes.

Detailed explanation-4: -The term used for crossing over is recombination. Recombination can occur between any two genes on a chromosome, the amount of crossing over is a function of how close the genes are to each other on the chromosome.

Detailed explanation-5: -In reality, crossing-over between chromatids during prophase I of meiosis mixes up pieces of chromosomes between homologue pairs, a phenomenon called recombination.