Microbial Genetics and Antimicrobial Drugs: Key
Concepts and Mechanisms Test with complete
solutions latest 2026/27 UPDATE
What are the two essential functions of DNA?
1) DNA serves as the genetic material responsible for inheritance. 2) DNA directs and regulates
the construction of proteins necessary for cell growth and reproduction.
What is a genome?
The full complement of DNA within a cell, organized into genes on chromosomes and plasmids.
What is gene expression?
The processes of transcription and translation where DNA is transcribed into RNA and then
translated into proteins.
What does the central dogma of molecular biology state?
DNA encodes messenger RNA (mRNA), which encodes proteins.
What is semiconservative replication?
A process where each strand of the double helix serves as a template for the production of a new
complementary strand, resulting in one old strand and one new strand in each double-stranded
DNA.
What role does helicase play in DNA replication?
Helicase separates the DNA strands by breaking the hydrogen bonds between nitrogenous base
pairs.
,What is the function of topoisomerase II (DNA gyrase) during DNA replication?
It relaxes the supercoiled chromosome to make DNA more accessible for replication initiation.
What is the role of RNA primase in DNA replication?
RNA primase synthesizes RNA primers needed to start replication.
What are Okazaki fragments?
Short stretches of DNA synthesized on the lagging strand during DNA replication.
Which enzyme removes RNA primers during DNA replication?
DNA polymerase I.
What is the function of DNA ligase?
It seals the gaps between Okazaki fragments on the lagging strand to create one continuous DNA
strand.
What is transcription in prokaryotes?
The process where the information encoded in DNA is transcribed into a strand of RNA.
What is the role of RNA polymerase during transcription?
RNA polymerase binds to the promoter sequence on DNA and synthesizes RNA in the 5' to 3'
direction.
What is the difference between the sense strand and the antisense strand of DNA?
The sense strand is the non-template strand that has the same sequence as the RNA transcript,
while the antisense strand is the template strand used for transcription.
, What happens during the termination phase of transcription?
RNA polymerase dissociates from the DNA template and releases the newly synthesized RNA
transcript.
What are exons and introns in eukaryotic genes?
Exons are coding regions that encode proteins, while introns are non-coding regions that do not
code for proteins.
What is RNA splicing?
The process of removing introns from the primary RNA transcript and reconnecting exons to
form mature mRNA.
What modifications are made to eukaryotic primary transcripts?
Addition of a 5' cap and a 3'-poly-A tail.
How does the structure of mRNA differ in prokaryotes and eukaryotes?
Prokaryotic mRNA is often polycistronic (encoding multiple proteins), while eukaryotic mRNA
is monocistronic (encoding a single protein).
What is the function of single-stranded binding proteins during DNA replication?
They bind to single-stranded DNA to prevent hydrogen bonding between DNA strands, keeping
them separated.
What is the direction of DNA synthesis during replication?
DNA is synthesized in the 5' to 3' direction.
Concepts and Mechanisms Test with complete
solutions latest 2026/27 UPDATE
What are the two essential functions of DNA?
1) DNA serves as the genetic material responsible for inheritance. 2) DNA directs and regulates
the construction of proteins necessary for cell growth and reproduction.
What is a genome?
The full complement of DNA within a cell, organized into genes on chromosomes and plasmids.
What is gene expression?
The processes of transcription and translation where DNA is transcribed into RNA and then
translated into proteins.
What does the central dogma of molecular biology state?
DNA encodes messenger RNA (mRNA), which encodes proteins.
What is semiconservative replication?
A process where each strand of the double helix serves as a template for the production of a new
complementary strand, resulting in one old strand and one new strand in each double-stranded
DNA.
What role does helicase play in DNA replication?
Helicase separates the DNA strands by breaking the hydrogen bonds between nitrogenous base
pairs.
,What is the function of topoisomerase II (DNA gyrase) during DNA replication?
It relaxes the supercoiled chromosome to make DNA more accessible for replication initiation.
What is the role of RNA primase in DNA replication?
RNA primase synthesizes RNA primers needed to start replication.
What are Okazaki fragments?
Short stretches of DNA synthesized on the lagging strand during DNA replication.
Which enzyme removes RNA primers during DNA replication?
DNA polymerase I.
What is the function of DNA ligase?
It seals the gaps between Okazaki fragments on the lagging strand to create one continuous DNA
strand.
What is transcription in prokaryotes?
The process where the information encoded in DNA is transcribed into a strand of RNA.
What is the role of RNA polymerase during transcription?
RNA polymerase binds to the promoter sequence on DNA and synthesizes RNA in the 5' to 3'
direction.
What is the difference between the sense strand and the antisense strand of DNA?
The sense strand is the non-template strand that has the same sequence as the RNA transcript,
while the antisense strand is the template strand used for transcription.
, What happens during the termination phase of transcription?
RNA polymerase dissociates from the DNA template and releases the newly synthesized RNA
transcript.
What are exons and introns in eukaryotic genes?
Exons are coding regions that encode proteins, while introns are non-coding regions that do not
code for proteins.
What is RNA splicing?
The process of removing introns from the primary RNA transcript and reconnecting exons to
form mature mRNA.
What modifications are made to eukaryotic primary transcripts?
Addition of a 5' cap and a 3'-poly-A tail.
How does the structure of mRNA differ in prokaryotes and eukaryotes?
Prokaryotic mRNA is often polycistronic (encoding multiple proteins), while eukaryotic mRNA
is monocistronic (encoding a single protein).
What is the function of single-stranded binding proteins during DNA replication?
They bind to single-stranded DNA to prevent hydrogen bonding between DNA strands, keeping
them separated.
What is the direction of DNA synthesis during replication?
DNA is synthesized in the 5' to 3' direction.
