AP BIOLOGY

Detailed explanation-1: -Synapsis is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.

Detailed explanation-2: -The pairs of replicated chromosomes are known as sister chromatids, and they remain joined at a central point called the centromere.

Detailed explanation-3: -Pairing of homologous chromosomes is an essential feature of meiosis, acting to promote high levels of recombination and to ensure segregation of homologs.

Detailed explanation-4: -In metaphase I of meiosis I, the pairs of homologous chromosomes, also known as bivalents or tetrads, line up in a random order along the metaphase plate. The random orientation is another way for cells to introduce genetic variation.