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.

38. Based on the figure, which of the 2 mutant S. cere­visiae strains, if either, has(have) a mutation that affects Meiosis I ?

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

Looking at the picture, compared with the wild-type strain, the Meiosis I of the Mutant B strain is the same as the Meiosis I of the wild-type strain, and the Meiosis I result of the Mutant A strain is different from that of the wild-type strain, indicating that In Mutant A strain, the mutation directly affects Meiosis I