Question 1

What is true in both Temperate Phage and HIV infections?
A) There can be a long latent period where no sign of infection, such as cell death, is detectable.
B) Cell lysis always occurs immediately after virus introduction.
C) Assembled viral particles are always found within the cell.

Accepted Answer

Both Temperate Phage and HIV infections can have a long latent period where no sign of infection, such as cell death, is detectable.

Question 2

Which is a property of emerging viruses?
A) mutate frequently
B) recent origin
C) more likely to cause infection compared to other strains
D) all of these

Accepted Answer

Emerging viruses are characterized by their frequent mutations, recent origin, and a higher likelihood of causing infection compared to other strains. This is why all of the choices given are properties of emerging viruses.

Question 3

The genetic material of HIV is single-stranded RNA.

Accepted Answer

HIV is a retrovirus, which means it has single-stranded RNA as its genetic material. Upon infecting a host cell, the RNA is transcribed into double-stranded DNA using the enzyme reverse transcriptase, which can then be integrated into the host cell's genome.

Question 4

What was the outcome of the experiment that reconstituted two different strains of tobacco mosaic viruses that had different infection characteristics?
A) The differences in infection characteristics  depended only on the RNA sequence of the virus strain.
B) The differences in infection characteristics depended only the the protein coat.
C) The differences in infection characteristics depended on an RNA and protein coat interaction.

Accepted Answer

The experiment demonstrated that the infection characteristics of the tobacco mosaic virus were determined by the RNA sequence, not the protein coat.

Question 5

What is the genetic material in the T4 bacteriophage?
A) double-stranded DNA
B) single-stranded DNA
C) single-stranded RNA
D) double-stranded RNA

Accepted Answer

T4 bacteriophage contains double-stranded DNA as its genetic material.

Question 6

Which virus uses reverse transcriptase in its reproductive cycle?
A) HIV
B) Phage lamda
C) Both of the viruses use reverse transcriptase
D) Neither of the viruses use reverse transcriptase

Accepted Answer

HIV is the virus that uses reverse transcriptase in its reproductive cycle. Reverse transcriptase is an enzyme that allows the virus to create a DNA copy of its RNA genome, which can then be integrated into the host cell's DNA. This process is crucial for the replication and transmission of the virus. Phage lamda, on the other hand, is a bacteriophage that does not use reverse transcriptase.

Question 7

A bacteriophage that is physically integrated into the host chromosome is called a ________.
A) heteroduplex
B) envelope phage
C) prophage
D) plaque

Accepted Answer

When a bacteriophage integrates its DNA into the host chromosome, it becomes a prophage. This means that the viral genetic material is replicated along with the host DNA during cell division, and the viral genes are passed on to daughter cells. This integration is a type of lysogeny, which is a state of dormancy in which the phage does not cause lysis of the host cell. It can remain in this state until a trigger, such as stress or damage to the host DNA, causes it to become active again and enter the lytic cycle. Heteroduplex refers to a DNA molecule that is composed of two strands that are different in their nucleotide sequence or origin. Envelope phage refers to a type of virus that has a lipid bilayer membrane derived from the host cell when it exits from the cell, whereas plaque refers to a clear area of bacteriolysis on a bacterial lawn that is caused by a virus.

Question 8

What is the genetic material in the parvovirus?
A) single-stranded DNA
B) double-stranded DNA
C) single-stranded RNA
D) double-stranded RNA

Accepted Answer

Parvovirus contains a single-stranded DNA as its genetic material.

Question 9

Most biologists consider viruses to be living organisms,which are classified with the bacteria.

Accepted Answer

Most biologists do not consider viruses to be living organisms as they cannot replicate or carry out metabolic functions without a host cell. They are often classified separately from bacteria.

Question 10

A ________ frequently integrates into the host genome,forming prophages and utilizing a lysogenic cycle to manufacture new phages.
A) virulent phage
B) temperate phage
C) bacteria
D) eukaryotic cell

Accepted Answer

Temperate phages are capable of integrating their genome into the host genome, forming prophages. This allows them to utilize a lysogenic cycle to manufacture new phages, rather than immediately lysing the host cell like virulent phages. Bacteria and eukaryotic cells are not phages and do not integrate into host genomes.

Question 11

A ________ uses the lytic cycle to begin the immediate manufacture of new phages in the host cells. 
A) virulent phage
B) temperate phage
C) bacteria
D) eukaryotic cell

Accepted Answer

Virulent phages only use the lytic cycle to replicate and release new phages, causing the host cell to lyse and die. Temperate phages can incorporate their DNA into the host cell's genome and use lysogenic cycle as well. Bacteria and eukaryotic cells are not relevant to this question.

Quiz 10: Genetics of Viruses

What is true in both Temperate Phage and HIV infections?

Which is a property of emerging viruses?

The genetic material of HIV is single-stranded RNA.

What was the outcome of the experiment that reconstituted two different strains of tobacco mosaic viruses that had different infection characteristics?

What is the genetic material in the T4 bacteriophage?

Which virus uses reverse transcriptase in its reproductive cycle?

A bacteriophage that is physically integrated into the host chromosome is called a ________.

What is the genetic material in the parvovirus?

Most biologists consider viruses to be living organisms,which are classified with the bacteria.

A ________ frequently integrates into the host genome,forming prophages and utilizing a lysogenic cycle to manufacture new phages.

A ________ uses the lytic cycle to begin the immediate manufacture of new phages in the host cells.