Question

In bacterial DNA replication, synthesis starting from the site of origin of replication
a. Involves RNA primers
b. Requires telomerase
c. Proceeds unidirectionally
d. Moves bidirectionally

Answer 1

Hint: The biological process of producing two identical templates of DNA from one original DNA molecule is referred to as DNA replication. DNA replication is the most crucial part of the inheritance of genetic information that occurs in all living organisms. It is the prime way of transmitting information genetic in nature to the next generation.

Complete answer:
DNA possesses a double helix of two complementary strands. These strands are separated during the process of DNA replication. In a cell, the origin of replication is the specific site where DNA replication begins in the genome. DNA replicates semi-conservatively, it was first shown in E. Coli.
In living cells, such as E.Coli, a set of catalysts preferably enzymes are required for the process of replication.

DNA replication in bacteria:
Three major types of RNAs are known to us- mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA). mRNA provides the template, tRNA brings amino acids and reads the genetic code and rRNAs play structural and catalytic roles during translation. A single type of DNA dependent RNA polymerase is there that catalyzes the transcription of all types of RNA in bacteria.

Process-
• Initiation: Transcription is initiated when RNA polymerase binds to the promoter. It uses nucleoside triphosphate as a substrate and polymerizes in a template-dependent fashion.
• Elongation: involves opening of DNA helix. Only a small fragment of RNA remains bound to the enzyme.
• Termination: After reaching the terminator region both the nascent RNA and RNA polymerase falls off. This leads to termination.

In the bacterial DNA replication process, synthesis starting from the site of origin of replication moves bidirectionally.
Hence, the correct answer is option (D).

Note: In bacterial transcription-
The RNA polymerase can only catalyse the process of elongation. It associates transiently with initiation factor and termination factor to initiate and terminate the transcription respectively.
Also in case of bacterial DNA replication-
• No processing is required for mRNA.
• Since there is no separation of cytosol and nucleus transcription and translation takes place in the same compartment.
• Several times it happens that before the full transcription of mRNA translation may start.