MCQs On Microbiology

MCQs On Microbiology

1. Which of these bacterial components is least likely to contain useful antigens?

1. Cell wall
2. Flagella
3. Ribosomes
4. Capsule

2. Which of the following contains structures composed of N-acetylmuramic acid and N- acetylglucosamine?

1. Mycoplasmas
2. Amoeba
3. E.coli
4. Spheroplast

3. The association of endotoxin in gram-negative bacteria is due to the presence of

1. Steroids
2. Peptidoglycan
3. Lipopolysaccharides
4. Polypeptide

4. The prokaryotic cell membrane

1. Contains metabolic enzymes
2. Is selectively permeable
3. Regulates the entry and exit of materials
4. Contains proteins and phospholipids

5. Which of the statements regarding gram staining is wrong?

1. Mycobacterium tuberculosis stains blue because of the thick lipid layer
2. Streptococcus pyogenes stains blue because of a thick peptidoglycan layer
3. Escherichia coli stains pink because of a thin peptidoglycan layer
4. Mycoplasma pneumoniae is not visible in the Gram’s stain because it has no cell wall

6. Which of the following is not a recognised cause of diarrhoea?

1. Vibrio cholerae
2. Escherichia coli
3. Clostridium perfringens
4. Enterococcus faecalis

7. Which of the following is a gram-positive eubacterium?

1. Actinomyces
2. Clostridium
3. Rhizobium
4. Clostridium, Actinomyces

8. Which of the following microorganisms is not responsible for urinary tract infection?

1. Proteus mirabilis
2. Escherichia coli
3. Klebsiella pneumoniae
4. Bacteroides fragilis

9. Which of the following is diagnosed by serologic means?

1. Actinomycosis
2. Q-fever
3. Pulmonary tuberculosis
4. Gonorrhea

10. Diarrhoea is not caused by

1. Shigella dysenteriae
2. Streptococcus pyogenes
3. Clostridium difficile
4. Salmonella enteriditis

11. The coagulase is done to differentiate

1. Staphylococcus aureus from Staphylococcus epidermidis
2. Staphylococcus epidermidis from Neisseria meningitidis
3. Streptococcus pyogenes from Enterococcus faecalis
4. Streptococcus pyogenes from Staphylococcus aureus

12. Prokaryotic cells are more resistant to osmotic shock than eukaryotic cells because

1. Their cell wall is composed of peptidoglycan
2. They are selectively permeable
3. They contain osmoregulating porins
4. They block water molecules from entering the cell

13. The bacterial genus where sterols are present in the cell membrane is

1. Vibrio
2. Mycoplasma
3. Escherichia
4. Chlamydia

14. The bacterium that infects other gram-negative bacteria is

1. Proteus mirabilis
2. Haemophilus influenza
3. Bdellovibrio
4. Pseudomonas putida

15. Which phage is used for phage display technique?

1. T7
2. M13
3. ƛ-phage
4. ɸ6

Answer Key

1- c	2- c	3- c	4- d	5- a
6- d	7- d	8- d	9- b	10- b
11- a	12- a	13- b	14- c	15- b