Question 1

Which of the following best describes the structure of a prokaryotic chromosome as seen in the provided images?

Accepted Answer

Circular DNA molecule with a single origin of replication

Question 2

What is the primary function of DNA polymerase during DNA replication?

Accepted Answer

Synthesizes new DNA strands by adding nucleotides in the $$5' \rightarrow 3'$$ direction

Question 3

In the lac operon model, what happens when lactose is present and glucose is low?

Accepted Answer

Allolactose binds to the repressor, inactivating it and allowing transcription of structural genes

Question 4

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 5

A frameshift mutation is most likely to result from which of the following genetic events?

Accepted Answer

Insertion or deletion of one or more nucleotide pairs

Question 6

During transcription in prokaryotes, which sequence signals the end of transcription?

Accepted Answer

Terminator sequence

Question 7

Which of the following statements about the genetic code is correct?

Accepted Answer

The genetic code is degenerate, meaning multiple codons can encode the same amino acid

Question 8

What is the default state of a repressible operon, such as the trp operon?

Accepted Answer

On, unless a corepressor activates the repressor

Question 9

Which of the following best explains the effect of UV radiation on DNA?

Accepted Answer

It causes the formation of thymine dimers, disrupting normal base pairing

Question 10

Which enzyme is responsible for separating thymine dimers during DNA repair?

Accepted Answer

Photolyase

Question 11

In bacterial conjugation, what is the result when an F factor plasmid is transferred from an F+ cell to an F– cell?

Accepted Answer

The recipient cell becomes an F+ cell

Question 12

Which of the following is a function of R factors found in plasmids?

Accepted Answer

Encode antibiotic resistance

Question 13

A missense mutation results in:

Accepted Answer

A change in the amino acid sequence due to a base substitution

Question 14

Which of the following best describes horizontal gene transfer in bacteria?

Accepted Answer

Transfer of genes between cells of the same generation

Question 15

Which enzyme is responsible for synthesizing RNA primers during DNA replication?

Accepted Answer

Primase

Question 16

What is the role of RecA protein in genetic recombination?

Accepted Answer

Catalyzes the joining of two DNA strands during crossing over

Question 17

Which of the following is a real-world consequence of mutations and recombination in microbial populations?

Accepted Answer

Increased diversity and selection of the fittest organisms by natural selection

Question 18

A bacterial cell exposed to ionizing radiation is most likely to experience which of the following?

Accepted Answer

Formation of ions that react with nucleotides and the deoxyribose-phosphate backbone

Question 19

Which of the following best describes the function of transposons?

Accepted Answer

Segments of DNA that can move from one region of DNA to another

Question 20

In the context of gene regulation, what is the advantage of regulating protein synthesis at the gene level?

Accepted Answer

It is energy-efficient because proteins are synthesized only as needed

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

Guida di studio - Domande di pratica