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10 sample questions
Major Diseases And Cures MCQ Practice Test
Learn about significant illnesses and the history of their treatments.
Q1. Which of the following gene therapy approaches is *being investigated* as a potential treatment for leukocyte adhesion deficiency (LAD) type 1, a rare genetic disorder characterized by impaired leukocyte migration?
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A. CD18 gene editing using CRISPR-Cas9 ✓
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B. ITGB2 gene therapy using a lentiviral vector
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C. SLAMF6 gene therapy
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D. ITGAM gene editing using TALENs
Explanation: Several gene therapy approaches are being investigated for LAD1. CD18 gene editing using CRISPR-Cas9 targets the ITGB2 gene, which encodes the CD18 subunit of the integrin beta-2 (β2) complex. Other approaches include gene therapy using lentiviral vectors to deliver a functional copy of the ITGB2 gene.
Q2. Which of the following is a characteristic of the “shock and kill” strategy employed in the treatment of Leishmaniasis caused by Leishmania donovani?
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A. Inhibition of parasite replication in the liver
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B. Induction of a strong cell-mediated immune response
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C. Activation of macrophages to kill intracellular amastigotes ✓
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D. Enhancement of parasite susceptibility to oxidative stress
Explanation: The “shock and kill” strategy involves the use of drugs that activate macrophages to kill the intracellular amastigotes of Leishmania donovani, thereby reducing the parasite burden in the liver and spleen.
Q3. Which of the following gene editing tools has been used to successfully treat patients with sickle cell anemia and ¼-thalassemia by correcting the underlying genetic mutations in hematopoietic stem cells?
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A. CRISPR-Cas9 ✓
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B. TALENs
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C. ZFNs
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D. Base editing
Explanation: CRISPR-Cas9 has been used in clinical trials to treat patients with sickle cell anemia and ¼-thalassemia by correcting the underlying genetic mutations in hematopoietic stem cells. This approach involves using a CRISPR-Cas9 guide RNA to target the specific genetic mutation responsible for the disease, and then using the Cas9 enzyme to make a precise cut in the DNA, allowing for the introduction of a corrective gene edit. This technique has shown promise in treating these devastating genetic disorders.
Q4. What is the primary mechanism by which the antibiotic linezolid inhibits the growth of methicillin-resistant Staphylococcus aureus (MRSA)?
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A. It inhibits cell wall synthesis by binding to the 50S ribosomal subunit.
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B. It inhibits protein synthesis by binding to the 30S ribosomal subunit. ✓
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C. It inhibits DNA replication by binding to DNA gyrase.
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D. It inhibits fatty acid synthesis by blocking the enzyme acetyl-CoA carboxylase.
Explanation: Linezolid is an oxazolidinone antibiotic that works by binding to the 30S ribosomal subunit, thereby inhibiting protein synthesis in bacteria. This mechanism of action is unique among antibiotics and is responsible for its effectiveness against MRSA and other Gram-positive bacteria.
Q5. The "Paris syndrome" is a psychological condition where individuals experience a profound disappointment when visiting Paris, often accompanied by physical symptoms. Which of the following treatments is NOT typically used in the management of this condition?
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A. Psychotherapy
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B. Medication for anxiety and depression
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C. Hospitalization
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D. Immunosuppressants ✓
Explanation: Paris syndrome is a psychological condition, not an autoimmune disorder. It is often treated with psychotherapy, medication for anxiety and depression, and, in severe cases, hospitalization. Immunosuppressants are not used to treat this condition.
Q6. The antiviral drug clevudine was initially developed to target which of the following viral diseases?
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A. Hepatitis B ✓
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B. Hepatitis C
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C. Herpes Simplex
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D. HIV/AIDS
Explanation: Clevudine is a nucleoside analog that was initially developed to treat Hepatitis B. It works by inhibiting the replication of the Hepatitis B virus. Although it was not widely used due to side effects, it provided valuable insights into the treatment of Hepatitis B.
Q7. What is the primary mechanism by which the bacterium ©-lysozyme, found in human tears, exerts its antimicrobial effect against ©-hemolytic streptococci?
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A. It binds to the bacterial cell wall, preventing the incorporation of N-acetylglucosamine into the peptidoglycan layer.
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B. It cleaves the peptidoglycan layer of the bacterial cell wall, ultimately leading to bacterial lysis. ✓
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C. It inhibits the synthesis of the bacterial cell wall by interfering with the enzyme transpeptidase.
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D. It generates reactive oxygen species that damage the bacterial DNA, preventing replication.
Explanation: The enzyme ©-lysozyme is a key component of the innate immune system, and its mechanism of action against ©-hemolytic streptococci involves the cleavage of the peptidoglycan layer of the bacterial cell wall. This process ultimately leads to bacterial lysis and death.
Q8. Which of the following gene therapy approaches is currently used or has been approved for the treatment of Spinal Muscular Atrophy (SMA)?
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A. CRISPR-Cas9 mediated gene editing to disrupt SMN1 expression
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B. Base editing with TALENs to enhance SMN2 expression
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C. Gene replacement therapy using an AAV vector carrying a functional SMN1 gene ✓
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D. ZFNs-mediated gene editing for SMN1 activation
Explanation: Gene replacement therapy using an adeno-associated virus (AAV) vector carrying a functional SMN1 gene has been approved for the treatment of Spinal Muscular Atrophy (SMA). This therapy delivers a functional copy of the SMN1 gene to motor neurons, addressing the underlying genetic defect. Other approaches, such as targeting the SMN2 gene, are also used.
Q9. Which of the following is a key mechanism by which the antibiotic linezolid exerts its bacteriostatic effect against Gram-positive bacteria?
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A. Inhibition of protein synthesis at the 30S subunit of the ribosome
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B. Inhibition of cell wall synthesis through targeting penicillin-binding proteins
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C. Inhibition of protein synthesis at the 50S subunit of the ribosome ✓
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D. Inhibition of DNA replication by intercalating between DNA base pairs
Explanation: Linezolid is an oxazolidinone antibiotic that works by binding to the 50S subunit of the bacterial ribosome, thereby inhibiting protein synthesis and exerting its bacteriostatic effect. This is in contrast to other antibiotics that target the 30S subunit or cell wall synthesis.
Q10. The "sterile" filtration step in the production of the Salk poliovirus vaccine is primarily intended to remove which of the following?
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A. Host cell DNA
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B. Myeloid leukemia virus
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C. Reovirus
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D. Residual poliovirus ✓
Explanation: The "sterile" filter in the Salk inactivated poliovirus vaccine (IPV) production is designed to remove any residual, potentially infectious poliovirus particles. This ensures the vaccine is safe and does not cause vaccine-associated paralytic poliomyelitis (VAPP). The filter is not designed to remove host cell DNA, myeloid leukemia virus, or reovirus.
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