The parent cell that enters meiosis is diploid, whereas the four daughter cells that result are haploid.

Question

Which statement correctly describes how cellular DNA content and ploidy levels change during meiosis I and meiosis II?
View Available Hint(s)for Part C

A. DNA content is halved only in meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.
B. DNA content is halved only in meiosis I. Ploidy level changes from diploid to haploid only in meiosis II.
C. DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid only in meiosis II.
D. DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.

Answer 1

The correct statement is:

D. DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.

Explanation:

• During meiosis I, homologous chromosomes are separated, reducing the ploidy level from diploid (2n) to haploid (n). At this stage, the DNA content is halved as the cells go from having a full set of chromosomes to having only one chromosome from each homologous pair.
• During meiosis II, the sister chromatids of each chromosome are separated, further halving the DNA content but keeping the ploidy level at haploid (n) since the cells had already transitioned to haploid during meiosis I.

Thus, while DNA content is halved in both meiosis I and meiosis II, the transition from diploid to haploid occurs during meiosis I.