42

The table below shows the Baltimore Classification used to classify viruses based on their genetic material. What is the difference between how Group I and Group III viruses reproduce?

Table with two columns and nine rows. Top header row reads: Baltimore classification. Second row, left header reads: Group. Second row, right header reads: Characteristics. Third row, left cell reads: I. Third row, right cell reads: Double-stranded DNA. Fourth row, left cell reads: II. Fourth row, right cell reads: Single-stranded DNA. Fifth row, left cell reads: III. Fifth row, right cell reads: Double-stranded RNA. Sixth row, left cell reads: IV. Sixth row, right cell reads: Single-stranded RNA (+). Seventh row, left cell reads: V. Seventh row, right cell reads: Single-stranded RNA (–). Eighth row, left cell reads: VI. Eighth row, right cell reads: Single-stranded RNA with reverse transcriptase. Ninth row, left cell reads: VII. Ninth row, right cell reads: Double-stranded DNA with reverse transcriptase.

  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. What is a similar or different between the genome of Group I and Group VI, as well as how the two virus types reproduce?

Table with two columns and nine rows. Top header row reads: Baltimore classification. Second row, left header reads: Group. Second row, right header reads: Characteristics. Third row, left cell reads: I. Third row, right cell reads: Double-stranded DNA. Fourth row, left cell reads: II. Fourth row, right cell reads: Single-stranded DNA. Fifth row, left cell reads: III. Fifth row, right cell reads: Double-stranded RNA. Sixth row, left cell reads: IV. Sixth row, right cell reads: Single-stranded RNA (+). Seventh row, left cell reads: V. Seventh row, right cell reads: Single-stranded RNA (–). Eighth row, left cell reads: VI. Eighth row, right cell reads: Single-stranded RNA with reverse transcriptase. Ninth row, left cell reads: VII. Ninth row, right cell reads: Double-stranded DNA with reverse transcriptase.

  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. During which of the numbered steps does the amount of viral genetic material begin to change within the host cell and why?

This illustration shows an influenza virus attaching to an epithelial cell. At step 1, the virus enters the cell. At step 2, viral RNA enters the nucleus. At step 3, new viruses are assembled within the cell. At step 4, new viruses leave the host cell.

  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. How could the influenza virus change the function of a host cell? Which has the potential to produce the most copies of the virus?

This illustration shows an influenza virus attaching to an epithelial cell. At step 1, the virus enters the cell. At step 2, viral RNA enters the nucleus. At step 3, new viruses are assembled within the cell. At step 4, new viruses leave the 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. Which cycle would maintain the DNA of the virus over several generations, and why?

This illustration compares the lytic and lysogenic cycles. In the lytic cycle, a bacteriophage infects a host bacterial cell. The phage DNA and the host DNA remain separate. The phage DNA replicates and new phage particles are assembled until the cell lyses, releasing new phage. In the lysogenic cycle, a bacteriophage infects a host cell. The phage DNA becomes incorporated into the host genome, and the cell divides. Sometimes, the phage DNA is excised from the host DNA and may enter the lytic cycle.
 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. Based on the diagram, identify whether the following statement is true or false, and explain why or why not: “The lysogenic cycle allows viruses to preserve their genome during unfavorable conditions.”

This illustration compares the lytic and lysogenic cycles. In the lytic cycle, a bacteriophage infects a host bacterial cell. The phage DNA and the host DNA remain separate. The phage DNA replicates and new phage particles are assembled until the cell lyses, releasing new phage. In the lysogenic cycle, a bacteriophage infects a host cell. The phage DNA becomes incorporated into the host genome, and the cell divides. Sometimes, the phage DNA is excised from the host DNA and may enter the lytic cycle.

  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.