Question

Compare and contrast the INITIATION of DNA replication in bacteria and eukaryotic cells. Which of the following is a correct statement of what the two processes have in common? explain the answer for each statement.

1. Both prokaryotes and eukaryotes regulate the start of DNA replication through methylation of the chromosomal DNA.

2. Both prokaryotes and eukaryotes tend to use multiple origins of replication in a chromosome.

3. DNA replication in both prokaryotes and eukaryotes initiates at regions of DNA rich in A-T base pairs.

4. Both prokaryotes and eukaryotes regulate the start of DNA replication through phosphorylation of DNA helicase.

5. In both prokaryotes and eukaryotes, proteins that bind the DNA replication origin recruit DNA helicase.

Answer 1

Answer- the correct statement is '3'

Reason:- the explanation of each statement is as follows:-

1.DNA methylation is a process by which methyl groups are added to a DNA molecule. Methylation of DNA acts to repress gene transcription.

2.Prokaryotic chromosomes have only one origin of replication, where as, eukaryotic chromosomes have multiple origins as the eukaryotic chromosomes are larger in size.

3.the origin of replication site in both prokaryotes and eukaryotes are A-T base pair rich to facilitate unwinding as the A-T are 33% weaker than G-C.

5. The DNA helicase are the proteins that are recruited to the origin site . These unwinds and separates the DNA helix into single-stranded DNA.