Question

A cell at the end of S phase (DNA synthesis phase of interphase) contains 100 picograms of nuclear DNA. If this cell undergoes meiosis, how much nuclear DNA will be in each daughter cell?

Answer 1

Each daughter cell from the original cell at the end of S phase will contain 46 chromatids or 100 picograms of nuclear DNA.

Step-by-step explanation:

During the S phase of meiosis, DNA replication occurs and results in the formation of identical sister chromatids. Each sister chromatid is a duplicated chromosome and is attached to its identical copy at the centromere. In a cell at the end of S phase, there are 92 chromatids (46 chromosomes x 2 copies).

During meiosis, these chromatids are separated into different daughter cells. In meiosis I, the chromosomes pair up and undergo crossing over, resulting in genetic recombination. Then, the pairs of homologous chromosomes separate, resulting in two daughter cells, each with 46 chromatids (23 pairs of sister chromatids). In meiosis II, the sister chromatids from each chromosome separate, resulting in four daughter cells, each with 46 chromatids.

Therefore, each daughter cell from the original cell at the end of S phase will contain 46 chromatids or 100 picograms of nuclear DNA.