Q: Which of the following equations represents the central dogma of molecular biology?

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

Question 1

Which of the following best describes the role of a capsid in a virus?

Accepted Answer

It is the protein coat that covers and protects the viral genome.

Question 2

A bacteriophage infects a bacterial cell and integrates its DNA into the host genome, remaining dormant for several generations. What is this phase called?

Accepted Answer

Lysogenic cycle

Question 3

Which enzyme is responsible for converting viral RNA into DNA in retroviruses?

Accepted Answer

Reverse transcriptase

Question 4

A positive sense RNA virus can immediately begin protein synthesis upon entering a host cell because:

Accepted Answer

Its genome has the same sequence as mRNA and can be directly translated.

Question 5

Which of the following statements about prions is correct?

Accepted Answer

Prions are infectious proteins that cause brain diseases by inducing misfolding of normal proteins.

Question 6

What is the main difference between the lytic and lysogenic cycles in bacteriophages?

Accepted Answer

The lytic cycle results in host cell death, while the lysogenic cycle allows the viral genome to persist without killing the host.

Question 7

Which type of viral genome requires reverse transcription before integration into the host genome?

Accepted Answer

Single-stranded RNA (ssRNA-RT)

Question 8

Viroids differ from viruses in that viroids:

Accepted Answer

Are composed solely of short, circular RNA and lack a protein coat.

Question 9

Which of the following best explains why restriction enzymes are important in bacterial defense against viruses?

Accepted Answer

They degrade viral DNA, preventing replication of virulent phages.

Question 10

A virus with a double-stranded DNA genome typically replicates in which part of the host cell, and what is the key enzyme involved?

Accepted Answer

Nucleus; host DNA polymerase

Question 11

Which of the following equations represents the central dogma of molecular biology?

Accepted Answer

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

Question 12

A negative sense RNA virus must first undergo which process before its genome can be translated?

Accepted Answer

Transcription by viral RNA polymerase to produce complementary mRNA

Question 13

Which of the following is a correct sequence of events for retrovirus replication?

Accepted Answer

Reverse transcription of RNA to DNA, integration into host genome, synthesis of viral proteins

Question 14

Which structure is found in animal viruses but not in most bacteriophages?

Accepted Answer

Viral envelope

Question 15

A temperate phage is characterized by its ability to:

Accepted Answer

Replicate through both the lytic and lysogenic cycles.

Question 16

Which of the following best describes the replication strategy of a double-stranded RNA virus?

Accepted Answer

It uses viral RNA polymerase in the cytoplasm to replicate its genome.

Question 17

Which of the following is NOT a plausible consequence of prion infection?

Accepted Answer

Synthesis of viral RNA

Question 18

Which of the following best explains why viroids are primarily plant pathogens?

Accepted Answer

They replicate using host plant enzymes and disrupt plant growth.

Question 19

Which of the following is a correct representation of reverse transcription in retroviruses?

Accepted Answer

$$RNA \rightarrow DNA$$

Question 20

A virus infects a cell and uses the host's ribosomes, tRNA, and amino acids to synthesize its proteins. This process is best described as:

Accepted Answer

Viral replication

Biological and Chemical Properties of Viruses and Infectious Agents

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