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

Question 1

Which of the following best describes the relationship between genotype and phenotype in a bacterial cell?

Accepted Answer

Genotype is the genetic makeup that determines the phenotype, which is the observable traits.

Question 2

Which of the following statements about prokaryotic and eukaryotic genomes is CORRECT?

Accepted Answer

Prokaryotic genomes are usually circular and found in the nucleoid region.

Question 3

Which of the following is a structural difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 4

What is the significance of the antiparallel arrangement of DNA strands?

Accepted Answer

It enables complementary base pairing and proper association of the strands.

Question 5

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

Accepted Answer

Helicase

Question 6

During DNA replication, why is the lagging strand synthesized discontinuously?

Accepted Answer

Because the lagging strand is made in the opposite direction of helix unwinding, resulting in Okazaki fragments.

Question 7

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

Accepted Answer

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

Question 8

A mutation changes the codon UAU (tyrosine) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 9

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

Accepted Answer

They can confer antibiotic resistance to the host cell.

Question 10

Which process allows bacteria to transfer genetic material through a pilus?

Accepted Answer

Conjugation

Question 11

What is the role of DNA ligase during DNA replication?

Accepted Answer

It forms phosphodiester bonds to seal nicks in the DNA backbone.

Question 12

Which of the following is TRUE about inducible operons such as the lac operon?

Accepted Answer

They are off by default and activated only under certain conditions.

Question 13

A chemical mutagen causes the insertion of two nucleotides into a gene. What is the most likely effect on the resulting protein?

Accepted Answer

A frameshift mutation that alters the reading frame.

Question 14

Which of the following is a post-translational modification?

Accepted Answer

Addition of a phosphate group to a protein.

Question 15

What is the main advantage of redundancy in the genetic code?

Accepted Answer

It protects cells from the effects of some mutations.

Question 16

Which of the following best describes the function of the operator in an operon?

Accepted Answer

It binds the repressor to block transcription.

Question 17

Which enzyme is responsible for replacing RNA primers with DNA during replication?

Accepted Answer

DNA polymerase I

Question 18

A scientist exposes bacteria to UV light, which causes thymine dimers. Which DNA repair mechanism is most likely to fix this damage?

Accepted Answer

Excision repair

Question 19

Which of the following is a key difference between prokaryotic and eukaryotic DNA replication?

Accepted Answer

Eukaryotic DNA replication involves more protein factors and multiple initiation sites.

Question 20

Which of the following best describes a silent mutation?

Accepted Answer

A mutation that does not change the amino acid sequence.

Microbial Genetics: Structure, Function, and Regulation

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