$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 2

A mutation in the DNA sequence of a gene can lead to which of the following outcomes?

Accepted Answer

An altered mRNA, which may result in an altered protein and altered function

Question 3

Which enzyme is responsible for unwinding the DNA double helix during replication?

Accepted Answer

Helicase

Question 4

In the lac operon, what happens when lactose is present in the environment?

Accepted Answer

The repressor is inactivated by allolactose, allowing transcription

Question 5

Which of the following is a function of plasmids in bacteria?

Accepted Answer

They may carry genes for antibiotic resistance and can be transferred between cells

Question 6

What is the role of the promoter in transcription?

Accepted Answer

It is the site where RNA polymerase binds to initiate transcription

Question 7

Which of the following best describes a repressible operon?

Accepted Answer

It is turned off by the binding of a corepressor to the repressor, which then binds the operator

Question 8

Which of the following mutations would most likely result in a truncated (shortened) protein?

Accepted Answer

Nonsense mutation

Question 9

What is the function of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments on the lagging strand

Question 10

Which of the following statements about horizontal gene transfer is correct?

Accepted Answer

It involves the transfer of genes between cells of the same generation

Question 11

Which of the following best explains why the genetic code is described as 'degenerate'?

Accepted Answer

Some amino acids are coded by more than one codon

Question 12

Which process is responsible for the removal of introns and joining of exons in eukaryotic mRNA?

Accepted Answer

RNA processing by snRNPs

Question 13

A chemical mutagen causes adenine to pair with cytosine instead of thymine. What type of mutation is this?

Accepted Answer

Base substitution (point mutation)

Question 14

Which of the following is true about the lagging strand during DNA replication?

Accepted Answer

It is synthesized discontinuously, forming Okazaki fragments

Question 15

Which of the following is a real-life application of genomics in medicine?

Accepted Answer

Using bacterial genomes to design targeted antibiotics

Question 16

Which of the following best describes the function of tRNA during translation?

Accepted Answer

It transports amino acids to the ribosome and matches them to the mRNA codon

Question 17

Which of the following is a mechanism by which bacteria can repair UV-induced thymine dimers?

Accepted Answer

Photolyase-mediated light repair

Question 18

Which of the following is a characteristic of an inducible operon?

Accepted Answer

It is turned on in the presence of an inducer

Question 19

Which of the following best describes the role of cAMP in the regulation of the lac operon?

Accepted Answer

cAMP binds to the CAP protein, which then binds the promoter to enhance transcription

Question 20

Which of the following is a possible consequence of a frameshift mutation?

Accepted Answer

The reading frame is shifted, altering many downstream amino acids

Microbial Genetics: Structure, Function, and Regulation of Genetic Material

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