Free Acellular Life MCQs with Answers

• A. repeating the ELISA only
• B. the Western blot technique
• C. a blood culture on agar
• D. a chest X ray

Explanation: ELISA is sensitive but can give false positives, so Western blot, which separates the viral proteins and shows which antibodies are…

• A. during pregnancy, during delivery and through breastfeeding
• B. only through the genes she passes on
• C. only if the child is vaccinated
• D. never, since HIV requires a needle to spread

Explanation: Mother to child transmission can occur across the placenta, at birth and in breast milk, which is why antiretroviral treatment during…

• A. Sharing needles contaminated with infected blood
• B. Sexual contact with an infected person
• C. Transfusion of infected blood
• D. Sharing a meal with an infected person

Explanation: HIV needs direct access to blood or mucous membranes, so casual contact such as meals, handshakes and sneezing carries no risk.

• A. single drugs are too expensive to manufacture
• B. the drugs increase each other's side effects
• C. HIV develops resistance rapidly to any single drug
• D. they kill the virus directly by oxidation

Explanation: HIV mutates so fast that a population resistant to one drug soon appears, but becoming resistant to three at once is far harder.

• A. Oncoviruses
• B. Lentiviruses
• C. Spumaviruses
• D. Adenoviruses

Explanation: Lentiviruses, meaning slow viruses, cause long incubation, persistent infections, which fits HIV's years long course from infection to…

• A. prevent transmission of the virus through transfusion
• B. increase the storage life of the blood
• C. raise the red cell count of the unit
• D. detect anaemia in the donor

Explanation: One unit of infected blood can transmit HIV directly into the recipient's circulation, so screening donated blood is one of the most…

• A. makes vaccination unnecessary
• B. destroys the host's red blood cells
• C. binds to receptors on host cells and allows the virus to enter
• D. makes the virus resistant to heat

Explanation: gp120 projects from the envelope and locks onto CD4 receptors, the first step of infection, which is why it is also the main target…

• A. It can be cured with a course of antibiotics
• B. It survives for weeks on dry surfaces
• C. It is commonly spread by mosquito bites
• D. It destroys helper T cells and progressively weakens immunity

Explanation: HIV replicates inside helper T lymphocytes and destroys them, so immunity collapses and opportunistic infections follow.

• A. They always infect animal cells only
• B. Their RNA acts directly as mRNA
• C. They lack protein coats
• D. They use reverse transcriptase to make DNA from RNA

Explanation: A retrovirus reverses the usual flow of information by copying its RNA genome into DNA, which integrase then inserts into the host…

• A. Measles
• B. Influenza
• C. Hepatitis A
• D. AIDS

Explanation: AIDS destroys or severely weakens CD4 helper T cells, reducing immune coordination and allowing opportunistic infections to develop.

• A. helper-T
• B. B
• C. both T and B
• D. none of these

Explanation: HIV mainly infects helper T lymphocytes because the virus attaches to the CD4 receptor on these cells, gradually weakening specific…

• A. HAV
• B. HIV
• C. Rabies
• D. Pigs

Explanation: AIDS is caused by human immunodeficiency virus, or HIV, which progressively damages immune cells, especially CD4 T lymphocytes.

• A. SsRNA
• B. DsRNA
• C. SsDNA
• D. DsDNA

Explanation: HIV is an enveloped single-stranded RNA virus and is a retrovirus because it uses reverse transcriptase to make DNA from its RNA genome.

• A. Polio
• B. Hepatitis
• C. AIDS
• D. HIV

Explanation: AIDS is the advanced syndrome caused by HIV, involving severe immune deficiency and opportunistic problems such as pneumonia, lymph-node…

• A. is a host specific disease
• B. An infected mother cannot pass the virus to her baby.
• C. Results in enlargement of lymph nodes
• D. Can be prevented.

Explanation: An infected mother can transmit HIV to her baby during pregnancy, childbirth, or breastfeeding, so that statement is incorrect.

• A. HAV
• B. HBV
• C. HCV
• D. HEV

Explanation: HCV commonly persists after the initial infection and can cause chronic hepatitis, cirrhosis and hepatic failure.

• A. Paramyxovirus
• B. Rhinovirus
• C. Arbovirus
• D. Rhabdovirus

Explanation: Rabies is caused by rabies virus, a member of the genus Lyssavirus in the family Rhabdoviridae, whose virions are characteristically…

• A. DNA
• B. RNA
• C. Protein
• D. Both A & B

Explanation: Viruses have genomes made of nucleic acid, and different viruses may contain either DNA or RNA, although an individual virus normally…

• A. Circulate
• B. Move
• C. Reproduce
• D. Are crystalline

Explanation: Viruses resemble living organisms because they can reproduce inside a suitable host cell using the host's machinery.

• A. Poliomyelitis
• B. Common cold
• C. Yellow fever
• D. Diphtheria
• E. Encephalitis

Explanation: Diphtheria is caused by the bacterium Corynebacterium diphtheriae, not by a virus.