Question

Which one of the following statements is not true for all E. coli DNA polymerases?

a) They synthesize DNA in the 5′ to 3′ direction.
b) They require a primer to initiate DNA synthesis.
c) They have 3′ to 5′ exonuclease activity.
d) They initiate synthesis without a primer.

Answer 1

The statement that is not true for all E. coli DNA polymerases is that they initiate synthesis without a primer.

Step-by-step explanation:

The correct option is d) They initiate synthesis without a primer. All other statements are true for E. coli DNA polymerases. DNA polymerases synthesize DNA in the 5′ to 3′ direction (option a) and they require a primer to initiate DNA synthesis (option b). E. coli DNA polymerases also have 3′ to 5′ exonuclease activity (option c).

However, they do require a primer to initiate synthesis and cannot initiate synthesis without a primer, so option d) is not true for E. coli DNA polymerases.