Question

During DNA replication in a bacterium, a G is accidentally incorporated instead of an A into one newly synthesized DNA strand. Imagine that this error was not corrected and that it has no effect on the ability of the progeny to grow and reproduce.

After this original bacterium has divided once, what proportion of its progeny would you expect to contain the mutation?

What proportion of its progeny would you expect to contain the mutation after three more rounds of DNA replication and cell division?

During DNA replication in a bacterium, a G is accidentally incorporated instead of an A into one newly synthesized DNA strand. Imagine that this error was not corrected and that it has no effect on the ability of the progeny to grow and reproduce.

After this original bacterium has divided once, what proportion of its progeny would you expect to contain the mutation?

What proportion of its progeny would you expect to contain the mutation after three more rounds of DNA replication and cell division?

Answer 1

DNA replication is semi-conservative i.e. each daughter duplex contains one parental strand and one newly-synthesized strand.
Parental duplex: G:T
After one round of replication: G:C and A:T
Half the progeny would contain the mutation after one round of replication

After two rounds of replication: G:C, G:C, A:T, and A:T

After three rounds of replication: G:C, G:C, G:C, G:C, A:T, A:T, A:T, and A:T
Half the progeny would contain the mutation after three rounds of replication