What is meant by a “pulse-chase”experiment? What procedures were followed? What were thecells labeled with? In what cell compartment was the labelfound? The first labeled mitotic cells were observedabout 4-5 hours after the end of the labeling period. Mitoticcells continued to appear over the next 6-8 hours. These dataled researchers to conclude that S phase lasts about 6-8 hours, and G2 lasts about 4 hours. Explain their reasoning.