Biology ยท General Awareness

Viral Diseases and Immunity

807 Questions

Viral diseases and immunity cover the structure, transmission, and diagnosis of viruses like HIV. Questions focus on disease pathways, immune responses, and prevention. Strong knowledge here provides an edge in biology scoring.

HIV and AIDS structureVirus transmission methodsImmune system deficiencyPathogen risk groupsMedical diagnosis methods

Viral Diseases and Immunity Questions

Multiple choice

Which immune marker is observable during the window period of HIV infection?

  1. Antigen p24

  2. Antibodies to gp 120

  3. Antibodies to gp 41

  4. Antigen p17
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The window period is the period between the onset of HIV infection and the appearance of detectable antibodies to the virus. The purpose of the p24 antigen portion of the test is to detect HIV before body has made antibodies, i.e. in the window period.

Multiple choice

Which among the following treatments is regarded the best for HIV infection?

  1. Reverse transcriptase inhibitors

  2. Protease inhibitors

  3. Integrase inhibitors

  4. Highly active anti-retroviral therapy (HAART)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

HAART is used to suppress HIV viral replication and the progression of HIV disease. It conjoins three or more different drugs such as two nucleoside reverse transcriptase inhibitors (NRTIs) and a protease inhibitor. These HAART regimens have proven to reduce the amount of active virus in many cases.

Multiple choice

The structural component of HIV required for cell -cell fusion is

  1. gp 120

  2. gp 41

  3. p24

  4. P2 protein
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For the HIV infection to occur, the cell fusion is essential. This is done by the trans-membrane glycoprotein gp 41. HIV-1 utilises two major co-receptors along with CD4 to bind to, fuse with and enter target cells.

Multiple choice

Many drugs have been developed to treat AIDS (acquired immunodeficiency syndrome), caused by HIV (human immunodeficiency virus). The drugs are basically nucleoside reverse transcriptase inhibitors. Which of the following compounds is a famous anti-HIV drug?

  1. Abrin

  2. Amethopterin

  3. 6-mercaptopurine

  4. AZT

  5. Thymidine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

AZT (Azido dideoxythymidine) also called zidovudine is an inhibitor of the usual RNA-directed DNA synthesis of the AIDS virus, and hence a famous anti-HIV drug.

Multiple choice

Which of the following causes AIDS?

  1. Amoeba

  2. HIV

  3. Vibrio cholera

  4. Lactobacillus

  5. Plasmodium vivax
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

HIV (Human Immuno-deficiency Virus) causes acquired immune-deficiency syndrome or AIDS. It is a retro virus with RNA as genetic material.

Multiple choice

Assertion: Human immunodeficiency virus is spherical with a diameter of about 90-120 nm. Reason: Its genome consists of single-stranded DNA associated with reverse transcriptase enzyme.

Directions: In the following question, there are two statements, Assertion (A) and Reason (R). Consider both the statements independently and mark your answer as

1. if both A and R are correct and R is the correct explanation of A
2. if both A and R are correct and R is not the correct explanation of A
3. if A is correct and R is incorrect
4. if A is incorrect and R is correct
5. if both A and R are incorrect

  1. Both A and R are correct and R is the correct explanation of A.

  2. Both A and R are correct and R is not the correct explanation of A.

  3. A is correct and R is incorrect.

  4. A is incorrect and R is correct.

  5. Both A and R are incorrect.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This option is correct because human immunodeficiency virus (HIV) is spherical with a diameter of about 90-120 nm. Its genome consists of single-stranded RNA associated with reverse transcriptase enzyme.

Multiple choice

What is the mode of transmission of AIDS?

  1. Air

  2. Water

  3. Physical contact

  4. Sexual contact
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

AIDS is primarily transmitted through sexual contact, along with other routes like blood transmission and from mother to child during pregnancy/birth. It is NOT transmitted through air (like influenza), water (like cholera), or casual physical contact like touching or hugging. This is a crucial public health fact about HIV/AIDS.

Multiple choice

Which of the following is a retrovirus?

  1. HIB

  2. HIV

  3. Influenza virus

  4. Rabbis virus

  5. Phage virus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A retrovirus is an RNA virus, which replicates inside a host cell by the process of reverse transcription. Initially it employs its own reverse transcriptase enzyme to produce DNA from its RNA genome. This is the opposite of the normal pattern and hence, it is called retro or backwards. This new DNA is in turn included into the host's genome by an integrase enzyme.