

MCQOPTIONS
This section includes 53 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.
1. |
Chemically the capsule may be |
A. | polypeptide |
B. | polysaccharide |
C. | either (a) or (b) |
D. | none of these |
Answer» D. none of these | |
2. |
Peptidoglycan is found only in the bacterial |
A. | cell membrane |
B. | glycocalyx |
C. | cell wall |
D. | spore |
Answer» D. spore | |
3. |
The cell walls of Gram positive bacteria contain two modified sugar, viz. N- acetylgucosamine (NAG) and N- acetylmuramic acid (NAM). They are covalently linked by |
A. | - 1,4-glycosidic bond |
B. | -1,6-glycosidic bond |
C. | - 1,6-glycosidic bond |
D. | - 1,4-glycosidic bond |
Answer» E. | |
4. |
Which of the following organism has sterols in their cytoplasmic membrane? |
A. | <i>Clostridum</i> |
B. | <i>Proteus</i> |
C. | <i>Mycoplasma</i> |
D. | <i>Bacillius</i> |
Answer» D. <i>Bacillius</i> | |
5. |
Porins are located in |
A. | the outer membrane of gram-negative bacteria |
B. | the peptidoglycan layer of gram-positive bacteria |
C. | the cytoplasmic membrane of both gram-negative and gram-positive bacteria |
D. | the periplasmic space of gram-negative bacteria |
Answer» B. the peptidoglycan layer of gram-positive bacteria | |
6. |
Which of the following is exposed on the outer surface of a gram-negative bacterium? |
A. | O-antigen of lipopolysaccharide (LPS) |
B. | Polysaccharide portion of lipoteichoic acid (LTA) |
C. | Braun lipoprotein |
D. | Electron transport system components |
Answer» B. Polysaccharide portion of lipoteichoic acid (LTA) | |
7. |
Which of the following does not contain protein? |
A. | Pili |
B. | Flagellum |
C. | Lipoteichoic acid |
D. | Porin |
Answer» D. Porin | |
8. |
Swimming towards a chemical of bacteria is termed as |
A. | positive chemotaxis |
B. | negative chemotaxis |
C. | phototaxis |
D. | magnetotaxis |
Answer» B. negative chemotaxis | |
9. |
Microcapsules are composed of |
A. | proteins |
B. | polysaccharides |
C. | lipids |
D. | all of these |
Answer» E. | |
10. |
Gram positive cells have a |
A. | second outer membrane that helps to retain the crystal violet stain |
B. | multiple layer of peptidoglycan that helps to retain the crystal violet stain |
C. | thick capsule that traps the crystal violet stain |
D. | periplasmic space that traps the crystal violet |
Answer» C. thick capsule that traps the crystal violet stain | |
11. |
Teichoic acids are typically found in |
A. | cell walls of gram positive bacteria |
B. | outer membranes of gram positive bacteria |
C. | cell walls of gram negative bacteria |
D. | outer membranes of gram negative bacteria |
Answer» B. outer membranes of gram positive bacteria | |
12. |
The bacteria deficient in cell wall is |
A. | <i>Treponema</i> |
B. | <i> Mycoplasma</i> |
C. | <i>Staphylococcus</i> |
D. | <i>Klebsiella</i> |
Answer» C. <i>Staphylococcus</i> | |
13. |
The common word for bacteria which are straight rod in shape is |
A. | cooci |
B. | bacilli |
C. | spirilla |
D. | pleomorphic |
Answer» C. spirilla | |
14. |
A single polar flagella is known as |
A. | monotrichous |
B. | lophotrichous |
C. | amphitrichous |
D. | none of these |
Answer» B. lophotrichous | |
15. |
The cocci which forms a bunch and irregular pattern are |
A. | <i>Staphylococci</i> |
B. | <i>diplococci</i> |
C. | <i>Tetracocci</i> |
D. | <i>Streptococci</i> |
Answer» B. <i>diplococci</i> | |
16. |
Chemotaxis is a phenomenon of |
A. | swimming away of bacteria |
B. | swimming towards a bacteria |
C. | swimming away or towards of bacteria in presence of chemical compound |
D. | none of the above |
Answer» D. none of the above | |
17. |
Cytoplasmic inclusions include |
A. | ribosomes |
B. | mesosomes |
C. | fat globules |
D. | all of these |
Answer» E. | |
18. |
Peptidoglycan is also known as |
A. | N-acetyl muramic acid |
B. | murein mucopeptide |
C. | N acetylglucosamine |
D. | mesodiaminopimetic acid |
Answer» C. N acetylglucosamine | |
19. |
Which of the following may contain fimbriae? |
A. | Gram-positive bacteria |
B. | Gram-negative bacteria |
C. | Both (a) and (b) |
D. | None of these |
Answer» C. Both (a) and (b) | |
20. |
Peptidoglycan accounts for __________ of the dry weight of cell wall in many gram positive bacteria |
A. | 50% or more |
B. | About 10% |
C. | 11%+ 0.22% |
D. | About 20% |
Answer» B. About 10% | |
21. |
Bacteria having no flagella are unable to |
A. | move |
B. | reproduce |
C. | stick to tissue surfaces |
D. | grow in nutrient agar |
Answer» B. reproduce | |
22. |
Which of the following is true about cell wall of gram-positive bacteria? |
A. | It consists of multiple layers |
B. | It is thicker than that associated with gram-negative bacteria |
C. | It contains teichoic acids |
D. | All of these |
Answer» E. | |
23. |
The cell walls of many gram positive bacteria can be easily destroyed by the enzyme known as |
A. | lipase |
B. | lysozyme |
C. | pectinase |
D. | peroxidase |
Answer» C. pectinase | |
24. |
The structure responsible for motility of bacteria is |
A. | pilli |
B. | flagella |
C. | sheath |
D. | capsules |
Answer» C. sheath | |
25. |
The next to last step in peptidoglycan biosynthesis is |
A. | synthesis of the NAM-peptide subunit |
B. | removal of the subunit from bactoprenol |
C. | linking the sugar of the disaccharide-peptide unit to the growing peptidoglycan chain |
D. | cross-linking the peptide side chains of peptidoglycan |
Answer» D. cross-linking the peptide side chains of peptidoglycan | |
26. |
Genetic system is located in the prokaryotes in |
A. | nucleoid |
B. | chromatin |
C. | nuclear material |
D. | all of these |
Answer» E. | |
27. |
The last step in synthesis of peptidoglycan is |
A. | attachment of a peptide to muramic acid |
B. | attaching two amino acids to form a cross-link |
C. | attachment of a portion of peptidoglycan to a membrane lipid |
D. | binding of penicillin to a membrane protein |
Answer» C. attachment of a portion of peptidoglycan to a membrane lipid | |
28. |
Which of the following is not true about peptidoglycan? |
A. | It is a polymer consisting of N-acetyl glucosamine, N-acetyl muramic acid and amino acids (alanine, lysine, etc.) |
B. | It is present in prokaryotic cell wall |
C. | It occurs in the form of a bag shaped macro molecule surrounding the cytoplasm membrane |
D. | None of the above |
Answer» E. | |
29. |
Which of the following has peptidoglycan as a major constituent of cell wall? |
A. | Gram-negative bacteria |
B. | Gram-positive bacteria |
C. | Fungi |
D. | None of these |
Answer» C. Fungi | |
30. |
The common word for bacteria which are helically curved rods is |
A. | cooci |
B. | pleomorphic |
C. | bacillus |
D. | spirilla |
Answer» E. | |
31. |
Single or clusters of flagella at both poles is known as |
A. | monotrichous |
B. | petritrichous |
C. | amphitrichous |
D. | none of these |
Answer» D. none of these | |
32. |
Which of the following bacterial genera (that produces endospore) have medical importance? |
A. | <i>Clostridium</i> |
B. | <i>Bacillus</i> |
C. | Both (a) and (b) |
D. | None of these |
Answer» D. None of these | |
33. |
The cocci which forms a chain is |
A. | <i>Streptococci</i> |
B. | <i>diplococci</i> |
C. | <i>Staphylococci</i> |
D. | <i>Tetracocci</i> |
Answer» B. <i>diplococci</i> | |
34. |
The arrangement, in which flagella are distributed all round the bacterial cell, is known as |
A. | lophotrichous |
B. | amphitrichous |
C. | peritrichous |
D. | monotrichous |
Answer» D. monotrichous | |
35. |
Periplasm is |
A. | the area between the inner and outer membranes of gram-negative bacteria |
B. | the area between the inner and outer membranes of Gram-positive bacteria |
C. | the interior portion of mitochondria |
D. | the area outside the cell membrane that is influenced by the polymers |
Answer» B. the area between the inner and outer membranes of Gram-positive bacteria | |
36. |
In which of the following, lipo-polysaccharide is a major constituent of outer membrane of the cellwall? |
A. | Gram-positive bacteria |
B. | Gram-negative bacteria |
C. | Fungi |
D. | None of these |
Answer» C. Fungi | |
37. |
Which of the following structure(s) is /are external to cell wall? |
A. | Flagella |
B. | Stalks |
C. | Sheath |
D. | All of these |
Answer» E. | |
38. |
The location where the bacterial chromosome concentrates is called |
A. | nucleus |
B. | nuclein |
C. | nucleoid |
D. | nucleose |
Answer» D. nucleose | |
39. |
Which of the following is analogous to mesosomes of bacteria? |
A. | Mitochondria of eukaryotes |
B. | Golgi apparatus of eukaryotes |
C. | Lysosomes of eukaryotes |
D. | None of these |
Answer» B. Golgi apparatus of eukaryotes | |
40. |
Which of the following has Chinese letter arrangement? |
A. | <i>Bacillus anthracis</i> |
B. | <i>Mycobacterium tuberculosis</i> |
C. | <i>Clostridium tetani</i> |
D. | <i>Corynebacterium diphtheriae</i> |
Answer» E. | |
41. |
The other name for peptidoglycan is |
A. | mucopeptide |
B. | murein |
C. | both (a) & (b) |
D. | none of these |
Answer» D. none of these | |
42. |
Cyanobacteria have |
A. | a gram-positive cell wall |
B. | a gram-negative cell wall |
C. | Neither (a) nor (b) |
D. | No cell wall |
Answer» C. Neither (a) nor (b) | |
43. |
Which of the following bacteria lack a cell wall and are therefore resistant to penicillin? |
A. | Cyanobacteria |
B. | Mycoplasmas |
C. | Bdellovibrios |
D. | Spirochetes |
Answer» C. Bdellovibrios | |
44. |
A cluster of polar flagella is called |
A. | lophotrichous |
B. | amphitrichous |
C. | monotrichous |
D. | petritrichous |
Answer» B. amphitrichous | |
45. |
Flagella move the cell by |
A. | many flagella beating in a synchronous, whip-like motion |
B. | an individual flagellum beating in a whip-like motion |
C. | spinning like a propeller |
D. | attaching to nearby particles and contracting |
Answer» D. attaching to nearby particles and contracting | |
46. |
The protein from which hook and filaments of flagella are composed of, is |
A. | keratin |
B. | flagellin |
C. | gelatin |
D. | casein |
Answer» C. gelatin | |
47. |
The cooci which mostly occur in single or pairs are |
A. | Streptococci |
B. | Diplococci |
C. | Tetracocci |
D. | None of these |
Answer» C. Tetracocci | |
48. |
The cell wall of |
A. | gram-positive bacteria are thicker than gram-negative bacteria |
B. | gram-negative bacteria are thicker than gram-positive bacteria |
C. | both have same thickness but composition is different |
D. | none of these |
Answer» B. gram-negative bacteria are thicker than gram-positive bacteria | |
49. |
In eukaryotic cells, ribosomes are |
A. | 70S |
B. | 60S |
C. | 80S |
D. | Not specific |
Answer» D. Not specific | |
50. |
The common word for bacteria which are spherical in shape is |
A. | cocci |
B. | bacilli |
C. | spirilla |
D. | pleomorphic |
Answer» B. bacilli | |