Internet Biology/Virus

AIDS:  The War Within --


Click on “AIDS lifecycle” and answer the following questions.



1.    List the four ways HIV is transmitted.


HIV is transmitted from one person to another through sex, sharing needles, or using contaminated blood products.  A mother can also pass HIV to her new baby. 


2.    List three ways in which the immune system fights off illness.


1)     Custom made antibodies

2)     Macrophages

3)     Killer T-cells


3.    How does the virus enter and infect the cell?


HIV has a special shape on its surface which fits perfectly into a shape on the T-cell. 


4.    Read how scientists are working to stop the virus at this stage.  (Click on “stop the virus”.)  Why does this not work so well?


Scientists are working on a decoy which would be put in a persons system.  By flooding the person’s system with the artificial decoy the HIV virus would attach itself to the decoys instead of the T-cells.


This doesn’t work well because the decoys do not remain in the body for long and they do not attach well to the circulating HIV found in the bloodstream.


5.    How does the virus’s genetic information (RNA) trick the cell’s genetic information (DNA)?


It is transcribed into a form that is identical to the cells DNA.  The genetic information hides out inside the nucleus of the cell escaping death from the body’s defenses.


6.    How do new pieces of the virus reproduce?


After a while, HIV comes out of the cell and begins to reproduce.  The DNA is transcribed into many copies of RNA, which in turn produce proteins for the new viruses.


7.    When is HIV considered AIDS?


A person is considered to have AIDS after a lot of their T-cells are destroyed.


8.    How does a person with AIDS usually die?


People with AIDS do not have a functioning immune system; therefore, they will probably die of one or many opportunistic infections.  These are diseases the make people sick only when their immune systems do not work.



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