SZABMU AHS 2026 Bacteriology Free Quiz 7

1. Which sigma factor is responsible for the general stress response in E. coli?

A. RpoD (sigma 70) B. RpoS (sigma S) C. RpoH (sigma 32) D. RpoN (sigma 54)

2. How is the lac operon regulated to preferentially use glucose?

A. Induction only B. Repression only C. Catabolite repression and induction D. Attenuation

3. Which mobile genetic elements can disrupt genes and facilitate horizontal gene transfer?

A. Plasmids B. Transposons C. Integrons D. Prophages

4. What are bacterial persisters?

A. Phenotypic tolerance B. Genetic resistance C. Biofilm formation D. Sporulation

5. How do efflux pumps contribute to antibiotic resistance?

A. Inactivate antibiotics B. Pump antibiotics out C. Modify target sites D. Reduce permeability

6. Why are biofilm-associated bacteria more resistant to antibiotics?

A. Due to genetic mutations B. Due to efflux pumps only C. Due to matrix and reduced metabolism D. Due to increased drug uptake

7. Which metabolic pathways allow bacteria to grow on acetate?

A. Glycolysis B. Pentose phosphate pathway C. TCA cycle only D. TCA cycle and glyoxylate shunt

8. What is the primary function of bacterial microcompartments like carboxysomes?

A. Optimize metabolic reactions B. Store nutrients C. Protect DNA D. Enhance motility

9. Which proteins are involved in organizing and compacting the bacterial nucleoid?

A. Histones B. HU and H-NS C. Topoisomerases D. DNA polymerases

10. What solutes do bacteria accumulate to counteract high external osmolarity without inhibiting metabolism?

A. Sugars B. Salts C. Glycine betaine D. Polyamines