Biology · 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

T-helpers during HIV infection can be bypassed by all of the following, except

  1. failure of regulatory T-cells

  2. polyclonal activation of B-cells

  3. idiotypic mechanisms

  4. antigenic cross-reaction

  5. T-cell recognition of carrier complexed to autoantigen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Failure of regulatory T-cells would release the T-helper for direct stimulation by antigen. This statement is therefore incorrect, since this would not be a bypass of the T-helpers.

Multiple choice

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

  1. p2 protein

  2. p24

  3. gp 41

  4. gp 120

  5. gp 160
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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

Multiple choice

Which of the following statements regarding human immunodeficiency virus is false?

  1. p32 is an integrase.

  2. p10 is a protease enzyme that breaks gag precursor.

  3. The reverse transcriptase enzyme is a prominent feature of retroviruses.

  4. Ras gene products are involved in kinase signalling pathways.

  5. Gag gene encodes for the lipid bilayer of the virus.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The gag gene is encoded as a large gag-pol protein with another gene then cleaved to the precursor protein assemblin, which is then cleaved to Gag. It is involved in virion assembly and produces some of the capsid and nucleocapsid proteins. It does not encodes for the lipid bilayer of the virus.

Multiple choice

A doctor told a couple that their son is a patient of plasmablastic lymphoma which is a rare and aggressive variant of diffuse large B-cell lymphoma. Which among the following viruses causes hematologic malignancies in such patients?

  1. Cytomegalovirus

  2. Human herpes virus 5

  3. Human herpes virus 4

  4. Human herpes virus 3

  5. Kaposi's sarcoma herpes virus (HHV-8)

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

HHV-8 infects lymphocytes and epithelial / endothelial cells and is the causative agent of Kaposi's sarcoma. It has also been associated with hematologic malignancies, including primary effusion lymphoma, multicentric Castleman's, MCD-related immunoblastic / plasmablastic lymphoma.

Multiple choice

Which of the following is most pertinent to healthy individuals with selective IgA deficiency?

  1. All individuals can be considered to be normal without risk of infections.

  2. They are more likely to develop heart disease than those with normal IgA levels.

  3. They will always have a high risk of HIV infection.

  4. They have a high risk of a recurrent serious bacterial infection.

  5. They have a higher risk of developing an organ specific autoimmune disease or allergies than the general population.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Organ-specific autoimmune diseases, are defined as disorders in which the body’s immune response attacks healthy cells in a specific organ.Individuals with selective IgA deficiency have a higher risk of developing an organ specific autoimmune disease or allergies than the general population.

Multiple choice

Vaibhav and his brother are HIV-infected. Which among the following fungi are recognised from the oral cavity of HIV-infected patients?

  1. Candida kefyr

  2. Candida glabrata

  3. Candida famata

  4. Candida dubliniensis

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

Candida dubliniensis has recently been recognised from the oral cavity of HIV-infected patients and are most frequently implicated in cases of recurrent infection following antifungal drug treatment.

Multiple choice

Which of the following statements about complications in AIDS patients is incorrect?

  1. Tuberculosis is a major cause of death in Africa.

  2. Candida infection of the oesophagus is a feature observed in such patients.

  3. After the diagnosis of AIDS is made, the average survival time has been estimated around 10 years.

  4. Malabsorption is common in such patients.

  5. Human herpes virus type 8 (HHV 8) results in malignancy.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

After the diagnosis of AIDS is made, the average survival time has been estimated to be 2-3 years.

Multiple choice

Epstein-Barr virus was the first virus to be directly associated with human cancer. Epstein-Barr virus is NOT implicated in which of the following conditions?

  1. Infectious mononucleosis

  2. Nasopharyngeal carcinoma

  3. Chronic lymphatic leukaemia

  4. Burkitt's lymphoma

  5. Post-transplantation lymphoproliferative syndrome

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is not thought to be due to an infection, but a relatively benign form of leukaemia in the elderly.