Question

At what phase of meiosis are homologous chromosomes separated?
A. At prophase II
B. At prophase I
C. At anaphase I
D. At anaphase II

Answer 1

Meiosis is a reductional division. It occurs in the germ cells of sexually reproducing organisms. The homologous chromosomes are separated during the meiosis I stage of the cell division.

Complete answer: Meiosis is a cell division by which gametes are made. In this process, we begin with 2n (diploid), and we end up with 4 non-identical n (haploid) daughters gametes, after two divisions. There are six stages involved in meiosis, namely prophase, metaphase, prometaphase, anaphase, telophase and cytokinesis. Meiosis is composed of two rounds of cell division, namely Meiosis I and Meiosis II. In anaphase I, the homologous chromosomes get pulled towards opposite poles of the cell as the spindle fibres separate the homologous pair.
i. Prophase I: In this stage, spindle fibres appear which is important for the successful division of the chromosomes. Homologous chromosomes exchange parts of themselves so that one chromosome contains both maternal and paternal DNA.
ii. Prophase II: This stage is identical to their counterparts in meiosis I.
iii. Anaphase II: Here, sister chromatids are pulled toward opposite poles of the equator.
Hence, the correct answer is option C.

Note: The process of meiosis is essential for all sexually reproducing organisms for the following reasons:
a. The meiosis maintains a constant number of chromosomes in sexually reproducing organisms through the formation of gametes.
b. By crossing over, the meiosis results in the exchange of the genes and thus, causes genetic variations among the species. These variations are the raw materials of the evolutionary process.
c. Each round of division contains a period of karyokinesis (nuclear division) and cytokinesis (cytoplasmic division).