Q40 - Rate and Fidelity of DNA Replication in Fast-Growing E. coli
The fast growing model bacterium E. coli (generation time = 20 min) has a single 4.6 million base pair large chromosome that can be replicated in 42 minutes from a single origin of replication.
Using the information and data, determine which of the statements are true or which are false.
A. In E. coli, DNA polymerase synthesizes about 900 bp/second including proof reading activity.
B. An E. coli cell always contains two copies of its genome just prior to cell division when growing at highest possible growth rate
C. During replication, the enzyme primase forms a short RNA sequence, which is extended by DNA polymerase. This is why the genome just after replication contains multiple short stretches of RNA
D. E. coli DNA polymerase III synthesizes DNA with an error rate of 1 wrong nucleotide per 1000 bases, that is why the genome after replication contains about 4600 mutations
Question reproduced from IBO 2015, Theoretical Exam B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)