Question

If crossing over did not occur, what would be the identity of cells after meiosis II?

a. Cells would have identical chromatids.
b. Crossing over does not affect chromosome identity.
c. Cells would exhibit increased genetic diversity.
d. Chromatids remain identical only in the absence of meiosis.

Answer 1

Without crossing over, cells after meiosis II would have identical chromatids, as crossing over is responsible for genetic variation in meiosis by creating recombinant chromosomes.

Step-by-step explanation:

If crossing over did not occur, the identity of cells after meiosis II would be that cells would have identical chromatids. Crossing over is an essential process in meiosis I where homologous chromosomes pair up and exchange segments of their genetic material, leading to recombinant chromosomes. This process results in increased genetic variation because the sister chromatids held together by the centromere are no longer identical after crossing over has taken place. During meiosis II, which resembles mitotic division, these chromatids separate, but due to the prior crossing over event, the resultant daughter cells contain recombined genomes. If crossing over did not happen, meiosis II would still occur, but the resulting cells would contain identical sets of chromosomes, similar to the outcome of a mitotic division.