If we continue to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II will be a. 0.25x. b. 0.5x. c. x. d. 2x.

Verified step by step guidance

1. Understand the stages of meiosis: Meiosis I and Meiosis II. Meiosis I reduces the chromosome number by half, while Meiosis II separates sister chromatids.
2. Recall that at the end of Meiosis I, each cell has half the original DNA content, which is represented as 'x' in a diploid cell. Thus, each cell at the end of Meiosis I has 0.5x DNA content.
3. Recognize that during Meiosis II, the DNA content does not change between the beginning and the end of this phase because it involves separation of sister chromatids without further DNA replication.
4. Identify that metaphase of Meiosis II is a stage where chromosomes (sister chromatids) align at the metaphase plate, ready to be separated, but the DNA content per cell remains the same as it was at the end of Meiosis I.
5. Conclude that the DNA content of a single cell at metaphase of Meiosis II is 0.5x, which corresponds to option 'b. 0.5x.'

Key Concepts

Meiosis

Meiosis is a specialized form of cell division that reduces the chromosome number by half, resulting in four haploid cells from one diploid cell. It consists of two sequential divisions: meiosis I and meiosis II. During meiosis II, the sister chromatids are separated, similar to mitosis, but the overall chromosome number remains halved compared to the original cell.

Chromosome Content

The DNA content of a cell is often described in terms of 'x', where 'x' represents the basic haploid set of chromosomes. In diploid organisms, somatic cells have a DNA content of '2x', while gametes (sperm and egg cells) have a content of 'x'. Understanding the changes in DNA content during meiosis is crucial for determining the genetic makeup of the resulting gametes.

Metaphase II

Metaphase II is a stage in meiosis II where chromosomes align at the cell's equatorial plane. At this point, each chromosome consists of two sister chromatids, and the cell is preparing to separate these chromatids into two different cells. The DNA content at this stage is still 'x' for each chromatid, but since there are two chromatids per chromosome, the total content remains 'x' for each individual chromatid.