Activity #3 | DNA and Chromosome Structure

Picture 5: Multiple origins opening up replication forks on a double-stranded DNA sequence.

You accidentally get a cut on yourself and need to replace damaged cells. Assume that it takes 24 days to replicate your biggest chromosome if replication started at one end and went in one direction. You cannot replace a cell until all the chromosomes are replicated.

Quiz

Question

How much time would it take to replicate your largest chromosome if the origin of replication was in the middle, and replication was bidirectional?

48 days (double time)

24 days (full time)

12 days (half the time)

6 days (a quarter the time)

Looks Good!

Question

How much time would it take to replicate your largest chromosome if there are 500 origins of replication, evenly spaced, on the largest chromosome and bidirectional replication happens at each origin?

24 days (full time)

12 days (half the time)

12 days / 500 (just over half an hour!)

12 days / 500 / 2 (roughly 15 minutes!)

Looks Good!