AP BIOLOGY

Detailed explanation-1: -In the third step of mitosis, called metaphase, each chromosome lines up in a single file line at the center of the cell. By this point in time, the membrane enclosing the nucleus has dissolved, and mitotic spindles have attached themselves to each chromatid in all the chromosomes.

Detailed explanation-2: -Metaphase II: During metaphase, each of the 23 chromosomes line up along the center of the cell at the metaphase plate.

Detailed explanation-3: -Metaphase II: The paired chromosomes line up. Anaphase II: The chromatids split at the centromere and migrate along the spindle fibers to opposite poles. Telophase II: The cells pinch in the center and divide again.

Detailed explanation-4: -During meiosis, there are two rounds of cell division (i.e., meiosis 1 and meiosis 2), and thus two rounds of metaphase. During the first metaphase the tetrads line up along the center of the cell while during the second metaphase the homologous chromosomes line up along the center of the cell.

Detailed explanation-5: -In metaphase II, the chromosomes line up individually along the metaphase plate. In anaphase II, the sister chromatids separate and are pulled towards opposite poles of the cell. In telophase II, nuclear membranes form around each set of chromosomes, and the chromosomes decondense.