Free Kingdom Prokaryotae MCQs with Answers

51. Which part of bacteria is most delicate and damage to it can kill the bacteria?

• A. Cell wall
• B. Slime
• C. Capsule
• D. Cell membrane

Explanation: The cell membrane of bacteria is very delicate and any damage to it can kill the bacteria. It regulates functions like the transport of proteins, nutrients, metabolites, etc. It also contains enzymes for respiration. All the other components serve as protective materials that serve to prevent the rupturing of the cell membrane.

52. Which type of bacteria causes gonorrhoea?

• A. Gram-negative
• B. Gram-positive
• C. None of these
• D. E. coli

Explanation: Neisseria gonorrhoeae, the causative agent of gonorrhoea, is a Gram negative, coffee-bean shaped facultative intracellular diplococcus bacterium, the classical sexually transmitted bacteria.

53. Cyanobacteria help in nitrogen fixation because they have:

• A. Sodium channels
• B. Heterocysts
• C. Hormogonia
• D. Nitrogenase

Explanation: Cyanobacteria have specialized nitrogen-fixing cells called heterocysts which play a vital role in nitrogen fixation.

54. Tooth discoloration in children is caused by which antibiotic?

• A. Tetracycline
• B. Streptomycin
• C. Azythromycin
• D. Penicillin

Explanation: Tetracycline antibiotic has been found to cause permanent discoloration of teeth in kids below 8 years.

55. Bacteria plays an important role in:

• A. Phosphorus Cycle
• B. Nitrogen Cycle
• C. Carbon Cycle
• D. All of the above

Explanation: In nitrogen cycle :Nitrogen-fixing bacteria convert N2 to ammonia Nitrifying bacteria convert ammonia to nitrates and nitrites Denitrifying bacteria release the N2 back to the atmosphere by converting nitrates back to atmospheric nitrogen. In the carbon cycle, bacteria decompose dead organisms and release carbon back to the environment. In the phosphorus cycle, bacteria convert phosphate into the organic form so that it can be utilized by the plants.

56. E. coli is

• A. Anaerobic
• B. Gram negative
• C. Facultative
• D. All of the above

Explanation: E coli is a gram negative (Stains pink with Gram's stain), facultative and anaerobic microbe.

57. A bacteria without flagella is called:

• A. Amphitrichous
• B. Atrichous
• C. Lophotrichous
• D. Peritrichous

Explanation: Based on their flagella, bacteria can be classified as follows: Atrichous have no flagella (the suffix 'a' usually implies an absence of something) Monotrichous have one flagellum at one end only ('mono'=one) Lophotrichous have a tuft of flagella at one end ('lopho' = tuft) Bitrichous have one flagellum on each end ('bi'= two) Peritrichous have flagella all over the surface (peri = around) Amphitrichous have a tuft of flagella at both ends

58. Coccobacillus has a shape similar to which of the following?

• A. Rod
• B. Egg
• C. Ball
• D. None of these

Explanation: d) None of these: If none of the options accurately describes the shape of Coccobacillus, then this would be the correct answer. Coccobacillus is a type of bacteria that has a shape that is intermediate between cocci (spherical) and bacilli (rod-shaped). It is somewhat oval or egg-shaped, but not exactly like an egg.

59. Which of the following is a method of asexual reproduction?

• A. Sporulation
• B. Fission
• C. Apomixis
• D. All of these options are correct

Explanation: Sporulation: Leads to spore formation asexually. Fission: Mechanism of asexual reproduction in prokaryotes. Apomixis: asexual seed formation in higher plants where the ovum gets fertilized by another cell of the embryo sac. Since both cells are of the same parent, the reproduction is asexual regardless of gamete formation taking place. Hence, the all of these options are correct.

60. Which of these is a characteristic of prokaryotic cells?

• A. Absence of membrane bound cell organelles
• B. Presence of 70S ribosomes
• C. Both Options A and B are correct
• D. None of these

Explanation: Prokaryotic cells lack a nucleus, have no membrane-bound organelles, and have 70S ribosomes.