Test Prep for AP® Courses

42.

The table below shows the Baltimore Classification used to classify viruses based on their genetic material.

This is a two-column table titled Baltimore Classification. The columns from left to right are Group and Characteristics. The Groups column contains 1 to 7, one in each row. Across from each group number is their corresponding characteristics. Group 1, double-stranded D N A. Group 2, single-stranded D N A. Group 3, double-stranded R N A. Group 4, single-stranded R N A positive. Group 5, single-stranded R N A negative. Group 6, single-stranded R N A with reverse transcriptase. Group 7, double-stranded D N
Figure 21.21
What is the difference between how Group I and Group III viruses reproduce?
  1. In Group I, RNA is transcribed from an RNA genome while in Group III, RNA is transcribed from a DNA genome.
  2. In Group I, RNA is transcribed from a DNA genome while in Group III, RNA is transcribed from an RNA genome.
  3. In Group I, DNA is transcribed from a DNA genome while in Group III, RNA is transcribed from an RNA genome.
  4. In Group I, DNA is transcribed from an RNA genome while in Group III, RNA is transcribed from a DNA genome.
43.

The table below shows the Baltimore Classification used to classify viruses based on their genetic material.

This is a two-column table titled Baltimore Classification. The columns from left to right are Group and Characteristics. The Groups column contains 1 to 7, one in each row. Across from each group number is their corresponding characteristics. Group 1, double-stranded D N A. Group 2, single-stranded D N A. Group 3, double-stranded R N A. Group 4, single-stranded R N A positive. Group 5, single-stranded R N A negative. Group 6, single-stranded R N A with reverse transcriptase. Group 7, double-stranded D N
Figure 21.22
What is a similar or different between the genome of Group I and Group VI, as well as how the two virus types reproduce?
  1. Group I and VI viruses use RNA as their genome. Group I viruses reproduce by transcribing RNA from their DNA genome, while Group VI viruses first synthesize their RNA genome using reverse transcriptase before they can reproduce.
  2. Group I and VI viruses use DNA as their genome. Group I viruses reproduce by transcribing RNA from their DNA genome while group VI viruses first synthesize their DNA genome using reverse transcriptase before they can reproduce.
  3. Group I and VI viruses use DNA as their genome. Group I viruses reproduce by transcribing RNA from their DNA genome, while group VI viruses first synthesize RNA genome using reverse transcriptase before they can reproduce.
  4. Group I viruses use DNA as their genome while group VI use RNA. Group I viruses reproduce by transcribing RNA from their DNA genome while group VI viruses synthesize DNA from RNA using reverse transcriptase before they can reproduce.
44.

The diagram below shows the stages during which a virus infects a host cell.

This diagram shows the four steps during which a virus infects a cell, showing the influenza virus attaching to a target epithelial cell. In Step 1, the cell engulfs the virus by endocytosis. In Step 2, the viral contents are released and enter the nucleus where it is replicated by the viral RNA polymerase. In Step 3, viral mRNA is used to make viral proteins. In Step 4, new viral particles are made and released into the extracellular fluid. The cell is still intact and continues to make virus.
Figure 21.23
During which of the numbered steps does the amount of viral genetic material begin to change within the host cell and why?
  1. 1. virus enters the cell
  2. 2. virus RNA enters the nucleus
  3. 3. new viruses assemble within the cell
  4. 4. viruses leave the cell
45.

The diagram below shows the stages during which a virus infects a host cell.

This diagram shows the four steps during which a virus infects a cell, showing the influenza virus attaching to a target epithelial cell. In Step 1, the cell engulfs the virus by endocytosis. In Step 2, the viral contents are released and enter the nucleus where it is replicated by the viral RNA polymerase. In Step 3, viral mRNA is used to make viral proteins. In Step 4, new viral particles are made and released into the extracellular fluid. The cell is still intact and continues to make virus.
Figure 21.24
How could the influenza virus change the function of a host cell?
  1. because it replicates its DNA within the cell and reproduces, which could interfere with cell processes.
  2. because it replicates RNA within the cell and reproduces which could interfere with cell processes.
  3. because it attacks the immune system of the host cell, which would in turn interfere with cell processes.
  4. because it replicates its protein within the cell and reproduces, which could interfere with cell processes.
46.

The diagrams below model the lytic and lysogenic reproductive cycles of viruses. 

Diagram models the lytic and lysogenic reproductive cycles of viruses. The Lytic pathway goes in the downward direction on the left. It shows how the bacteriophage infects a cell and immediately replicates within the cell. The Lysogenic cycle pathway flows down on the right side and shows how the bacteriophage genome remains as a circular chromosome in the host until it enters a lytic cycle.
Figure 21.25
Which cycle would maintain the DNA of the virus over several
generations, and why?
  1. lysogenic, because the viral DNA can be excised from the host cell’s DNA when under stress
  2. lytic, because the viral DNA can be excised from the host cell’s DNA when under stress
  3. lytic, because the viral DNA can be passed on when the host cell replicates
  4. lysogenic, because the viral DNA can be passed on when the host cell replicates
47.

The diagrams below model the lytic and lysogenic reproductive cycles of viruses.

Diagram models the lytic and lysogenic reproductive cycles of viruses. The Lytic pathway goes in the downward direction on the left. It shows how the bacteriophage infects a cell and immediately replicates within the cell. The Lysogenic cycle pathway flows down on the right side and shows how the bacteriophage genome remains as a circular chromosome in the host until it enters a lytic cycle.
Figure 21.26
Based on the diagram, is the following statement true or false? Explain.
       The lysogenic cycle allows viruses to preserve their genome during unfavorable conditions.
  1. True, because when the host cell experiences unfavorable conditions, it stops dividing and stays in the same state.
  2. True, because the host cell in both the replication stage and during unfavorable conditions stays in the lysogenic cycle as it is more preferable over the lytic cycle.
  3. False, because when the host cell experiences unfavorable conditions, the prophage exits the genome and enters the lytic cycle.
  4. False, because when the host cell experiences unfavorable conditions, the virus enters latency period.