Assume That You Were Growing Cells in Culture and Had

Essay

Assume that you were growing cells in culture and had determined the cell -cycle time to be 24 hours. You introduce 3H thymidine and prepare autoradiographs of
metaphase chromosomes after 48 hours. Of the chromosomes that are labeled, you
expect two classes: one class that had completed one S phase in the label, and a second class that had completed a cellular division and an additional S phase in the label.
Draw the DNA (double -stranded) labeling pattern for each chromosome that you
would expect to find in these two types of metaphase chromosomes. (Use a broken line
{ - - -} for labeled single strands of DNA and a solid line for unlabeled single strands of DNA.)
a() metaphase chromosome having replicated once in label
b() metaphase chromosome having gone through two S phases in label