AP BIOLOGY

Detailed explanation-1: -In metaphase I, the tetrads line themselves up at the metaphase plate and homologous pairs orient themselves randomly. In anaphase I, centromeres break down and homologous chromosomes separate. In telophase I, chromosomes move to opposite poles; during cytokinesis the cell separates into two haploid cells.

Detailed explanation-2: -Metaphase I: The tetrads line up along the metaphase plate. Microtubules originating from the centrosomes at the 2 opposite poles of the cell attach to the kinetochores of each chromosome. Anaphase I: Homologous chromosomes are separated by the microtubules to opposite poles of the cell.

Detailed explanation-3: -Metaphase I: Instead of all chromosomes pairing up along the midline of the cell as in mitosis, homologous chromosome pairs line up next to each other. This is called synapsis. Homologous chromosomes contain the matching alleles donated from mother and father.

Detailed explanation-4: -In prophase I of meiosis, the homologous chromosomes form the tetrads. In metaphase I, these pairs line up at the midway point between the two poles of the cell to form the metaphase plate.

Detailed explanation-5: -Tetrad Formation in Meiosis In humans, sex cells contain 23 chromosomes. Therefore, 23 tetrads form during meiosis. During prophase I of meiosis I, the condensed homologous chromosomes line up to create tetrads, which are composed of two pairs of sister chromatids.