Question

A bacterium, containing one circular DNA chromosome, undergoes four rounds of replication. How many new strands of DNA would result?

Answer 1

After four rounds of replication, a bacterium with one circular DNA chromosome would result in 32 new strands of DNA, due to the semiconservative nature of replication, with doubling occurring each round.

Step-by-step explanation:

If a bacterium with one circular DNA chromosome undergoes four rounds of replication, each replication round would double the amount of DNA strands present. Starting with one circular chromosome, which consists of two strands of DNA, the first round of replication would result in 2 double-stranded DNA molecules (4 strands total). Consequently, the number of strands doubles with each subsequent replication:

Round 1: 4 strands (2 double-stranded)

Round 2: 8 strands (4 double-stranded)

Round 3: 16 strands (8 double-stranded)

Round 4: 32 strands (16 double-stranded)

Therefore, after four rounds of replication, there would be 32 new strands of DNA.

This replication process is known as semiconservative replication, where each of the two parental DNA strands serve as a template for the new DNA to be synthesized. After replication, each new DNA molecule consists of one parental (original) strand and one newly synthesized strand.

Answer 2

The correct answer is 32 strands.

Step-by-step explanation:

In bacterium, DNA replication is bidirectional which means it takes place in both directions. The origin of replication starts the replication, it is a specific sequence of nucleotides. Each strand of circular DNA acts as a parent strand to replicate its complementary new strand, resulting in two new DNA strands, one parent strand, and one new synthesized strand. So after the first round of replication, there are 4 strands formed.

Similarly, during the second round of replication each of the four strands will be synthesized lead to a total of 8 strands in the same manner. So by the same process in 3rd round will lead to 16 new strands and by the fourth round of replication 32 strands will be synthesized.

Thus, the correct answer is 32 strands.