Meiosis results in a change in chromosome number indicated by which transition in ploidy?

• A. $2n\to 4n$
• B. $n\to 2n$
• C. $n\to n$
• D. $2n\to n$

Answer: (D)

Verified step by step guidance

1. Understand that ploidy refers to the number of sets of chromosomes in a cell. For example, 2n means diploid (two sets), and n means haploid (one set).
2. Recall that meiosis is a type of cell division that reduces the chromosome number by half to produce haploid gametes from diploid cells.
3. Identify that the starting ploidy before meiosis is diploid (2n), and the resulting cells after meiosis are haploid (n).
4. Recognize that the transition in ploidy caused by meiosis is from 2n to n, which means the chromosome number is halved.
5. Compare the given options and select the one that correctly represents this reduction: from 2n to n.