A line of mouse cells is grown for many generations in a medium with 15N. Cells in G1 are then switched to a new medium that contains 14N. Draw a pair of homologous chromosomes from these cells at the following stages, showing the two strands of DNA molecules found in the chromosomes. Use different colors to represent strands with 14N and 15N. Q. Cells in anaphase of mitosis, after switching to medium with 14N

The figure below shows the number of chromosomes observed in an actively dividing cell at each stage of cell division. A B number of chromsomes per cell C 100 90 D 80 A bar graph comparing the number of chromosomes at different stages of cell division. 20 Which of the following best explains the change in the number of chromosomes between metaphase and anaphase? prophase metaphase anaphase telophase cytokinesis stage of cell division New chromosomes formed during prophase are doubled during anaphase. DNA replication occurs between metaphase and anaphase, doubling the number of chromosomes. During metaphase, a cell contains identical copies of each chromosome, and then trans- forms into sister chromatids. During anaphase, the chromatids are separated, each becoming independent chromo- somes in its respective new cell

A temperature-sensitive mutant yeast strain stops dividing when shifted from 25°C to 37°C.  These cells are analyzed at different temperatures by a machine that measures the amount of DNA they contain, and the following graphs are obtained. Cells in G1 phase should have ___ unit(s) amount of DNA. Which of the following would explain the behavior of your mutant? Mark yes or no for each of the following choices.  Inability to initiate DNA replication       Defect in chromosome condensation      Defect in centrosome duplication      Defect in cytokinesis