Help me with appropriate answer..

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Human Health and Disease

Short Answer Type

121.

Differentiate the following and give examples of each:
Active and passive immunity

168 Views

122.

Draw a well-labelled diagram of an antibody molecule.

292 Views

123.

What are the various routes by which transmission of human immuno-deficiency virus takes place?

178 Views

Long Answer Type

124.
What is the mechanism by which the AIDS virus causes deficiency of immune system of the infected person?

AIDS (Acquired Immuno Deficiency Syndrome) is caused by the Human immuno-deficiency virus (HIV). The HIV virus enters the human body by various methods like sharing infected needles, unprotected sexual contact with infected person, or infected blood transfusion. After entering the virus attacks and enters the macrophages. Inside the macrophages, the RNA of the virus is used to produce viral DNA by the process of reverse transcription. The viral DNA integrates itself into the host DNA and directs the synthesis of virus particles. Simultaneously the HIV enters helper T- lymphocytes and replicates to produce viral progeny there. The cell ruptures and releases newly formed progeny viruses into the blood, attacking other healthy helper T-lymphocytes in the body. As a result, the number of T-lymphocytes in the body of an infected person decreases progressively, thereby decreasing the immunity of a person.

219 Views