Passage VI

In the yeast Saccharomyces cerevisiae, the function of meiosis is to divide a diploid cell into 4 haploid cells called spores. During meiosis, the 2 copies of a chromosome, or homologs, undergo DNA replication (when each homolog becomes a linked pair of sister chromatids) followed by 2 rounds of chromosome segregation (separation into different cells) called Meiosis I and Meiosis II. The figure shows the homologs of a particular chromosome during meiosis in a wild-type S. cerevisiae strain and also in 2 mutant S. cerevisiae strains (Mutant A and Mutant B) each having a different mutation that affects meiosis.

35. According to the figure, how many cells are directly produced by Meiosis I in the Mutant A S. cerevisiae strain, and how many cells are directly produced by Meiosis I in the Mutant B S. cerevisiae strain?

Answer and Explanation

Your Answer is

Correct Answer is B

Explanation

From the figure in the article, it can be seen directly that during the production of Mutant A strain, there is only 1 cell after Meiosis I; in the process of Mutant B production, 2 cells are formed after Meiosis I, so option B is reasonable