Describe what happens to two homologous chromosomes as they go through (A) S phase, (B) prophase, (C) metaphase, and (D) anaphase of mitosis.

Question

Describe what happens to two homologous chromosomes as they go through (A) S phase, (B) prophase, (C) metaphase, and (D) anaphase of mitosis.

Answer 1

Lets call these homologous chromosomes T and t

(A) during S phase, you technically do NOT have chromosome. You have DNA. The DNA for future chromosomes T and t will double during S phase

(B) during prophase, the DNA supercoils into chromosomes. Since you have double the DNA, you end up with twice as many chromosomes T T and t t. The T and T will be attached to one another and comprise a structure called tetrad; another tetrad is formed by t and t.

(C) during metaphase, the 2 tetrads are lined up at the metaphase plate

(D) during anaphase, mitotic spindles pull each T of the first tetrad to opposite poles of the cell. The same happens to the other tetrad so that each t ends up in the opposite pole of the cell. In the end, mitosis yields 2 daughter cells that are genetically identical to the parent cell you start out with. Each daughter cell has 1 T and 1 t