Biology

Human Health and Disease

Question:

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

Answer:

HIV critically injures the immune system by infecting and eventually killing T-cells. Once the virus has infected a T cell, HIV copies its RNA into double stranded DNA copy by mearis of viral enzyme reverse transcriptase. This process is called reverse transcriptase because it violates the usual way in which genetic information is transcribed. Because reverse transcriptase lacks thg proofreading function that most DNA synthesizing enzymes have, many mutations arises as the virus replicates, further hindering the ability of the immune system to combat the virus. These mutations allow the virus to evolve rapidly resulting in the lost of vital cells. As a result of progressive destruction of its T-cells, the body is easily ravaged by a number of common infectious agents. In many instances, these infections would have caused little injury if there functional T-cells clones available.
Death ultimately results from the relentless attack of opportunistic pathogens or from the body's inability to fight off malignancies.
virus. These mutations allow the virus to evolve rapidly resulting in the lost of vital cells. As a result of progressive destruction of its T-cells, the body is easily ravaged by a number of common infectious agents. In many instances, these infections would have caused little injury if there functional T-cells clones available.
Death ultimately results from the relentless attack of opportunistic pathogens or from the body's inability to fight off malignancies.

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Human Health and Disease

Q 1.

Explain what is meant by metastasis.

Q 2.

List the harmful effects caused by alcohol/drug abuse.

Q 3.

How is a cancerous cell different from a normal cell?

Q 4.

What are the various public health measures, which you would suggest as safeguard against infectious diseases?
 

Q 5.

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

Q 6.

What are the various routes by which trans-mission of human immunodeficiency virus takes place?

Q 7.

In which way has the study of biology helped us to control infectious diseases?

Q 8.

In your view what motivates youngsters to take to alcohol or drugs and how can this be avoided?

Q 9.

What measures would you take to prevent water borne diseases?

Q 10.

The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its fall form:
(a)MALT (b) CMI
(c)AIDS (d)NACO
(e)HIV

Q 11.

Name the primary and secondary lymphoid organs.

Q 12.

Discuss with your teacher what does ‘a suitable gene' means, in the context of DNA vaccines.

Q 13.

Draw a well-labelled diagram of an antibody

Q 14.

Differentiate the following and give examples of each
(a)Innate and acquired immunity
(b)Active and passive immunity

Q 15.

Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with your teacher.

Q 16.

Hovy does the transmission of each of the following diseases take place?
(a)Amoebiasis (b) Malaria
(c)Ascariasis (d) Pneumonia

Q 17.

Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?