Name ______Date ______

Virus Replication Lab

Background info:

Viruses are very successful at invading the cells of other organisms. After a virus attaches itself to the outside of a host cell, a viral enzyme damages the cell membrane and allows the virus to enter the host cell. Some viruses inject their DNA into the host cell & leave their protein coat outside the cell; other viruses still have their coats on when they enter the host cell. Once the virus is inside the host cell, the viral DNA takes over the host cell’s genetic machinery causing the host cell to make copies of new viral DNA and protein coats. The virus parts are then assembled, and the new viruses escape from the host cell either by exocytosis or bursting out of the host cell.

Objective:

  • Trace the steps of viral replication in cells
  • Describe each step of viral replication
  • Construct an analogy for viral replication in cells

Material:

Scissors & Glue

Procedure:

  1. Cut out each of the 10 cartoon figure drawings on the sheet provided.
  1. Each of the cartoon drawings represents one of the stages of virus replication listed below. Identify the drawings that represent each stage of virus replication and line them up in order on your desk.

Stages of Virus Replication

  1. The virus attaches itself to the cell membrane of a host cell.
  2. A viral enzyme damages the host cell membrane; the virus invades the cell.
  3. The protein coat of the virus is removed.
  4. Viral genes (DNA) areactivated as they become part of the cell’s machinery
  5. The activated virus directs replication, the making of more viral genes (DNA.)
  6. The activated virus directs translation, the making of more viral protein coats.
  7. New genes (DNA) are completed.
  8. New protein coats are completed.
  9. The new viruses are assembled. DNA is inserted into the protein coats.

10. The new viruses escape from the cell.

  1. Label the small tab on each picture with the number of the stage of replication it represents using the numbers in the “Stages of Virus Replication” list, 1-10.
  2. Figure 4 in Data and Observations is a diagram representing the 10 stages of virus replication within a cell. Copy your numbers from the drawings onto this diagram in the spaces provided. (Refer to the list of the 10 stages).
  3. Place the drawings, each representing a stage of replication, under its proper label on the diagram in Figure 4 and glue them in place.
  4. Complete analysis questions below.

Analysis:

  1. In what ways is viral replication different from normal cell reproduction? ______
  2. Examine your completed diagram of virus replication. What happens in the steps called replicationtranslation? ______
  3. Describe the last stage before the new viruses escape. ______
  4. What do you think might happen to the cell after the viruses escape? ______
  5. If you were a scientist developing a new drug that would block viral replication, which steps would you choose to block? ______Explain your choice. ______
  6. This lab compares viral replication (the lytic cycle) to the making of a product in a factory. How is the lytic cycle different than a factory making a product?

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