Question

One species of primate usually has 48 chromosomes in its cells. In one particular female, cell division went awry and she produced one egg with an extra chromosome (25). The most probable source of this error is a mistake in which of the following?a. Either telophase I or II of meiosis b. Metaphase I of one meiotic event c. Either anaphase I or II of meiosis d. Cytokinesis at the end of meiosis II

Answer 1

Answer:

c. Either anaphase I or II of meiosis

Explanation:

During anaphase I homologous chromosomes separate, and they end up at opposite poles of the cell each having 2 chromatids, thus producing two daughter cells each with half the original chromosome number.

The two daughter cells resulting from meiosis I enter meiosis II, and during anaphase II the chromatids separate to opposite poles of the cells, producing a total of four daughter cells with half the original chromosome number and only one chromatid per chromosome.

• If something goes wrong during anaphase I one pair of the homologous chromosomes will migrate together to one pole of the cell, and after going through meiosis II there will be 4 daughter cells, two of them having an extra chromosome and two of them lacking one.

• If something goes wrong during anaphase II, the homologous chromosomes have separated but the chromatids of one of the chromosomes will migrate together, producing a total of 4 daughter cells: 2 normal, one with an extra chromosome and one lacking a chromosome.