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
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stimulation of immune response to cell surface antigens introduced by an inserted gene
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insertional mutation of a tumor suppressor gene
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use of a virus that contains an oncogene
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insertion of the viral genome adjacent to an oncogene
D
Correct answer
Explanation
Insertion of a retrovirus adjacent to an oncogene can activate that gene and lead to malignant transformation.
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Sharing a syringe
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Transfusion of contaminated blood
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Sexual contact with infected person
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Sharing contaminated razors
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Shaking hands with infected person
E
Correct answer
Explanation
Shaking hands with infected person cannot transmit HIV.
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It is caused by HIV- a retrovirus.
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Retroviruses have RNA genomes that replicate through DNA intermediate.
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AIDS is an immuodeficiency disorder.
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Viral RNA genome is converted into DNA copy with the help of reverse transcriptase.
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HIV infection can be controlled by using immunosupressents.
E
Correct answer
Explanation
Immunosupressents cannot control HIV infection.
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Enter the host cell via endocytosis.
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Do not require a receptor protein to recognize the host cell.
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Leave their capsid outside the host cell.
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Can reproduce independently of a host cell.
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Leave only their protein outside the host cell.
A
Correct answer
Explanation
Animal viruses attach by recognizing a receptor protein and entering through endocytosis.
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Blood transfusion
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Sharing needles
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Sharing shaving razors
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Mosquito bite
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Sexual contact with an infected person
D
Correct answer
Explanation
Mosquito bite does not transmit HIV.
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blood pressure
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other infections
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physical trauma
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inability to diagnose the disease
B
Correct answer
Explanation
AIDS (Acquired Immunodeficiency Syndrome) weakens the immune system by destroying CD4 cells, making the body vulnerable to opportunistic infections. Patients typically die from these secondary infections (pneumonia, tuberculosis, etc.) rather than the HIV virus itself.
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nerves
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bones
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hair
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lymph nodes
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Nervous system
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Respiratory system
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Immune system
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Muscular system
C
Correct answer
Explanation
HIV (Human Immunodeficiency Virus) specifically attacks and destroys cells of the immune system, particularly CD4 T-cells, weakening the body's ability to fight infections. It does not directly damage the nervous, respiratory, or muscular systems as its primary target.
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infected mother to baby during pregnancy
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breastfeeding from an infected female
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blood to blood contact with infected person
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handshaking
D
Correct answer
Explanation
The AIDS virus (HIV) is NOT transmitted through casual contact like handshaking, hugging, or sharing utensils. It spreads through specific routes: sexual contact, blood-to-blood contact, and from mother to child during pregnancy, childbirth, or breastfeeding. Handshaking involves no exchange of bodily fluids necessary for HIV transmission.
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Transfusion of infected blood
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Use of infected syringes
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Sexual contact with the infected person
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All of the above
D
Correct answer
Explanation
All are the modes of transmission of this disease.
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p55
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gp32
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gp41
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gp120
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gp140
D
Correct answer
Explanation
The surface protein gp120 conjoins the virus to the host lymphoid tissue by binding to the primary receptor CD4. It signals via several cell surface receptors.
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Gag gene encodes for the lipid bilayer of the virus.
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p32 is an Integrase.
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p10 is a protease enzyme that breaks gag precursor.
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The reverse transcriptase enzyme is a prominent feature of retroviruses.
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HIV is roughly spherical in shape.
A
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 encode for the lipid bilayer of the virus.
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Antigen p17
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p24 antigen
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Antibodies to gp41
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Antibodies to gp120
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Antigen p17
B
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.
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p2 protein
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gp41
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p24
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gp120
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p70
B
Correct answer
Explanation
For the HIV infection to occur the cell fusion is essential. This is done by the transmembrane glycoprotein gp41. HIV-1 utilises two major co-receptors along with CD4 to bind to, fuse with, and enter target cells.
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Reverse transcriptase inhibitors
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Protease inhibitors
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Integrase inhibitors
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Highly active antiretroviral therapy (HAART)
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Entry inhibitors
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 and in many case.