Exposure to the HIV virus doesn't necessarily mean that a person will develop AIDS. Some people have genetic resistance to infection by HIV. Dr. Stephen O'Brien from the U.S. National Cancer Institute has recently identified a mutant form of a gene, called CCR5, that can protect against HIV infection. The mutation probably originated in Europe and became more prevalent among survivors of the bubonic plague. The mutated gene prevents the plague bacteria from attaching to cell membranes and, therefore, from entering and infecting body cells.
Although the HIV virus is very different from the bacteria that causes the plague, both diseases affect the exact same cells and use the same method of infection. The presence of the mutated gene in descendants of plague survivors helps prevent them from contracting AIDS. Pharmaceutical companies are using this information as the basis for a new approach to AIDS prevention. This could be very important in areas of the world where the mutation is scarce or absent, such as Africa.
-Which of the following shows the steps of a viral infection in the proper order?

Question

Quizplus · Accepted Answer

The proper order of viral infection is that the virus locates the host cell, penetrates the cell membrane, enters the nucleus, alters the host cell DNA, and then the host cell produces copies of the virus. Option A is incorrect because the virus does not alter the host cell's DNA before it destroys the cell membrane. Option B is incorrect because the copies of the virus do not enter the host cell nucleus. Option D is incorrect because the process of forming hydrogen bonds is not part of a viral infection.

Exposure to the HIV Virus Doesn't Necessarily Mean That a Person