In: Biology
Which of the following statements about the general principles of chromosomal DNA replication in bacteria is FALSE?
a. |
Chromosomal DNA replication is unidirectional and requires a distinct origin for each strand |
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b. |
Both leading strand and lagging strand are synthesized simultaneously |
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c. |
The leading strand is replicated continuously; the lagging strand is replicated discontinuously |
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d. |
DNA or RNA can serve as primers |
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e. |
It requires the replisome |
In Bacteria, There is a circular chromosome in which there is a single origin of replication (point where DNA replication starts). DNA replication in bacteria requires the RNA primer formation with help of enzyme primase. DNA gyrase unwinds the DNA duplex and Primase forms the primer which is further extended by DNA polymerase III in both directions on two opposite strands. One strand is synthesized continuously while as the other strand is synthesized discontinuously in the form of okazaki fragments. The RNA primer is then removed and the gaps are filled by DNA polymerase I and joined to other fragments by ligase enzyme.
out of the given options, the option b, c and e are correct ones regarding DNA replication
Option a is not correct because DNA replication is bidirectional and requires single origin of replication for both the strands.
Option d is not correct because RNA serves as primer.
Therefore option a and d are the correct options for the question.