Norway rats have 42 chromosomes in their diploid cells. If a diploid rat cell enters meiosis, how many chromosomes and double-helical molecules of DNA will be present in each daughter cell at the end of meiosis II?

21 chromosomes

Explanation:

Meiosis is a type of cell division that produces 4 haploid daughter cells (i. e., gametes) from a single diploid cell. This parental cell undergo one (1) cycle of DNA replication and two (2) cell divisions, thereby, in the case of the Norway rats that have 42 chromosomes, the final number will be 21 (21 x 2 = 42)

21 chromosomes and 21 molecules of DNA at the end of meiosis II

Explanation:

The end of meiosis II that occurs on each cell will give rise to four mature cells, or gametes, and each cell will have 21 chromosomes because the number of each cell has to be half of the initial diploid cell to allow the correct number after the formation of the zygote. Each cell will also contain 21 molecules of DNA because the mature cell after the meiosis has to be haploid.