Q: Which of the following best describes the flow of genetic information according to the central dogma of molecular biology?

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

Question 1

Which of the following best describes the flow of genetic information according to the central dogma of molecular biology?

Accepted Answer

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

Question 2

A scientist is comparing the structure of DNA and RNA nucleotides. Which of the following features is found in RNA but NOT in DNA?

Accepted Answer

Ribose sugar

Question 3

During DNA replication, which enzyme is responsible for relieving supercoiling ahead of the replication fork?

Accepted Answer

Gyrase

Question 4

Which of the following statements correctly compares the leading and lagging strands during DNA replication?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized discontinuously in Okazaki fragments.

Question 5

In prokaryotic transcription and translation, which molecule carries the genetic code from DNA to the ribosome?

Accepted Answer

Messenger RNA (mRNA)

Question 6

A mutation changes a DNA sequence from $$	ext{TAC} to$$ $$	ext{TAA}. $$Using the mRNA codon table, what type of mutation is this?

Accepted Answer

Nonsense mutation

Question 7

Which of the following best explains why RNA viruses evolve more rapidly than DNA viruses?

Accepted Answer

RNA polymerases lack proofreading ability, leading to higher mutation rates.

Question 8

Which of the following is a correct description of an inducible operon?

Accepted Answer

It is usually OFF and can be turned ON when needed, such as the lac operon.

Question 9

A patient is diagnosed with tuberculosis. Which staining technique would be most useful for confirming the presence of Mycobacterium tuberculosis in a sputum sample?

Accepted Answer

Acid-fast stain

Question 10

Which of the following best describes the process of generalized transduction in bacteria?

Accepted Answer

A bacteriophage transfers bacterial DNA from one cell to another.

Question 11

Which of the following is NOT a criterion used to classify viruses?

Accepted Answer

Gram reaction

Question 12

A laboratory technician observes green structures inside pink/red bacterial cells after staining. What is the most likely interpretation?

Accepted Answer

The green structures are endospores, and the pink/red cells are vegetative cells.

Question 13

Which of the following best explains the medical importance of phage conversion?

Accepted Answer

It can increase bacterial virulence by introducing new traits.

Question 14

Which of the following laboratory methods is commonly used to culture viruses for vaccine production?

Accepted Answer

Embryonated eggs

Question 15

A scientist is studying a virus that integrates its genome into the host DNA and remains dormant for several generations. Which replication cycle is being described?

Accepted Answer

Lysogenic cycle

Question 16

Which of the following best describes the effect of a frameshift mutation?

Accepted Answer

It changes the reading frame, potentially altering every amino acid downstream.

Question 17

Which of the following is a feature of a negative simple stain?

Accepted Answer

The background is stained, and the cell remains clear.

Question 18

Which of the following best explains why bacteria use operons?

Accepted Answer

To efficiently regulate gene expression and conserve energy.

Question 19

Which of the following is a correct pairing of a bacterial shape and arrangement?

Accepted Answer

Streptococcus: chains of round cells

Question 20

A patient is infected with a retrovirus. Which process does the virus use to replicate its genome?

Accepted Answer

Reverse transcription ($$	ext{RNA} ightarrow 	ext{DNA})$$

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