Visual Connection Questions

Figure 21.4 Which of the following statements about virus structure is true?

1. All viruses are encased in a viral membrane.
2. The capsomere is made up of small protein subunits called capsids.
3. DNA is the genetic material in all viruses.
4. Glycoproteins help the virus attach to the host cell.

Figure 21.8 Influenza virus is packaged in a viral envelope that fuses with the plasma membrane. This way, the virus can exit the host cell without killing it. What advantage does the virus gain by keeping the host cell alive?

Figure 21.10 Which of the following statements is false?

1. In the lytic cycle, new phage are produced and released into the environment.
2. In the lysogenic cycle, phage DNA is incorporated into the host genome.
3. An environmental stressor can cause the phage to initiate the lysogenic cycle.
4. Cell lysis only occurs in the lytic cycle.