Question

Identify the meiotic stage in which the homologous chromosomes separate while the sister chromatids remain associated at their centromeres

• A. Anaphase II
• B. Metaphase I
• C. Anaphase I
• D. Metaphase II

Answer 1

The correct option is C

Anaphase I

The correct option is C:

Explanation of the correct option:

1. Meiosis is made up of two nuclear and cell division cycles named meiosis I and meiosis II, but just a single DNA replication cycle.
2. After the parental chromosomes have replicated to generate identical sister chromatids during the S phase, meiosis I begins.
3. Meiosis entails the pairing and recombination of homologous chromosomes.
4. Meosis I is divided into 4 stages:
   1. Prophase I
   2. Metaphase I
   3. Anaphase I
   4. Telophase I
5. During Anaphase I, homologous chromosomes split, while sister chromatids at centromeres stay together.

Explanation of the incorrect option:

Option A:

• Anaphase II: It starts with the centromeres of each chromosome (which were holding the sister chromatids together) separating at the same time, allowing them to migrate toward opposite poles of the cell.

Option B:

• Metaphase I: On the equatorial plate, the bivalent chromosomes align. Microtubules from the spindle's opposite poles connect to a pair of homologous chromosomes.

Option D:

• Metaphase II: At this point, the chromosomes align at the equator, and microtubules from opposing poles of the spindle bind to the sister chromatids' kinetochores.

Final answer: During Anaphase I of meotic phase homologous chromosomes separate while the sister chromatids remain associated at their centromeres