Question

Incubation time is the time for the symptoms of a disease to occur after exposure. Consider the data on incubation time of different viral diseases in the Table below. Use thedata to predict which diseases are caused by viruses that undergo the lytic cycle and whichare caused by viruses that undergo the lysogenic cycle. What is the possible public healthconsequence of the incubation time for diseases caused by proviruses (i.e., viral DNA thathas become part of the host chromosome)?

Answer 1

Defining Vocabulary

Let's define a couple of key terms:

• Lytic Cycle,: The lytic cycle is the "faster" virus cycle of the two. It consists of usually ,bacteriophages, that infect a host cell, replicates, then ,destroys, the cell.

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• Lysogenic Cycle,: The lysogenic cycle is the "longer" of the two cycles. It consists of viruses that infect the host cell but the viral genome ,fuses, with the host's DNA, lying ,dormant, for a long time.

Applying Definitions

Let's take what we just defined and apply it to the given data table.

We are given a data table with several different known viruses and their incubation time. This is a key category to look at to determine whether the virus follows the lytic or lysogenic cycle.

• Measles | Incubation Time: 9 - 11 days |

Since the incubation time is short, this virus follows the lytic cycle.

• Shingles | Incubation Time: years |

Since the incubation time is long, this virus follows the lysogenic cycle.

• Warts | Incubation Time: months |

Since the incubation time is long, this virus follows the lysogenic cycle.

• Cold | Incubation Time: 2 - 4 days |

Since the incubation time is short, this virus follows the lytic cycle.

• HIV | Incubation Time: 2 - 5 years |

Since the incubation time is long, this virus follows the lysogenic cycle.

Now we have filled out the entire data table!