AP BIOLOGY

Detailed explanation-1: -Recombination in meiosis. Recombination occurs when two molecules of DNA exchange pieces of their genetic material with each other. One of the most notable examples of recombination takes place during meiosis (specifically, during prophase I), when homologous chromosomes line up in pairs and swap segments of DNA.

Detailed explanation-2: -During prophase, chromatin condenses into chromosomes, and the nuclear envelope (the membrane surrounding the nucleus) breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles of the cell.

Detailed explanation-3: -Prophase I Figure 1: Recombination is the exchange of genetic material between homologous chromosomes. During prophase I, the chromosomes condense and become visible inside the nucleus.

Detailed explanation-4: -Crossing Over 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-5: -Prophase I: The nuclear envelope breaks down. The chromatin condenses into chromosomes. Homologous chromosomes containing the two chromatids come together to form tetrads, joining at their centromeres (2n 4c). This is when “crossing over” occurs, which creates genetic variation.