Trace the events occur in human body to cause immunodeficiency, when HIV gains entry into the Body
class 12th CBSE Biology sample paper
Answers
The HIV virus attacks the macrophages in human body.
1)RNA is replicated to form viral DNA by the enzyme reverse transcriptase .
2)Viral DNA gets incorporated into the host cell's DNA and directs the infected cell to produce viruses.
3)Macrophages continues to produce virus particles and function as HIV factory.
4)The virus particles enter helper T-Lymphocytes in the blood, Where they continue to replicate and produce viral progenies.
5)The number of helper T-Lymphocytes progressively decreases in the body of the infected person.
6)With the decrease in number of T-Cells, The immunity also decreases .
The person is unable to produce any immune response even against common bacteria like Mycobacterium , parasite like Toxoplasma, viruses and fungi.