AP BIOLOGY

Detailed explanation-1: -Meiosis also differs from mitosis in that it involves a process known as recombination, during which chromosomes exchange segments with one another. As a result, the gametes produced during meiosis are genetically unique.

Detailed explanation-2: -Crossing over occurs in meiosis but not mitosis because meiosis creates genetically unique cells and mitosis creates genetically identical cells. During meiosis in prophase I, crossing over occurs where homologous chromosomes exchange corresponding sections of DNA.

Detailed explanation-3: -This process is known as synapsis. Synapsis is when crossing over occurs. During crossing over, DNA is exchanged between two nonsister chromatids of a homologous pair of chromosomes.

Detailed explanation-4: -When homologous chromosomes form pairs during prophase I of meiosis I, crossing-over can occur. Crossing-over is the exchange of genetic material between homologous chromosomes. It results in new combinations of genes on each chromosome.

Detailed explanation-5: -During meiosis without crossing over, the alleles of two genes located on each chromosome migrate together and stay attached. We obtain, therefore, gametes that are 100% “parental", subdivided into two types of gametes from the point of view of allele separation.