Free Kingdom Prokaryotae MCQs with Answers

71. Spirochete is an example of which type of bacteria?

• A. Aerobic
• B. Facultative
• C. Anaerobic
• D. Both Options A and B are correct

Explanation: Spirochaeta are free-living nonpathogenic inhabitants of mud and water, typically thriving in anaerobic (oxygen-deprived) environments

72. In prokaryotes, the hair-like outgrowths which attach to the surface of other bacterial cells are _.

• A. Flagella
• B. Pili
• C. Capsules
• D. Plasmids

Explanation: Fimbriae and pili are hair-like appendages present on the bacterial cell wall similar to flagella. They are shorter than flagella and more in number. They are involved in the bacterial conjugation, attachment to the surface and motility.

73. The nitrifying bacteria are an example of which of the following?

• A. Heterotrophic bacteria
• B. Saprotrophic bacteria
• C. Chemosynthetic bacteria
• D. Parasitic bacteria

Explanation: Chemosynthetic bacteria oxidise inorganic compounds like ammonia, nitrate, nitrite, sulphur or ferrous ions and use the energy thus released for their synthetic reactions. Nitrifying bacteria are chemosynthetic.

74. What allows a bacteria to stain positively with gram stain?

• A. The bacteria is anaerobic
• B. The bacterial sample was pretreated with 3% ethanol
• C. The bacteria's periplasmic space
• D. The bacteria's thick peptidoglycan cell walls

Explanation: Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which allows them to take up the crystal violet colour of the Gram stain.

75. A giant micro organism, which was discovered in the intestine of brown surgeonfish (Acanthurus nigrofuscus), is:

• A. A bacterium
• B. A virus
• C. A parasite
• D. Protozoa

Explanation: Epulopiscium fishelsoni is a very large bacterium that only lives in the gut of a brown surgeonfish found in the Red Sea.

76. Which of the following is the most responsible factor for bacterial cell motility?

• A. Cillia
• B. Flagella
• C. Pili
• D. Pseudopodia

Explanation: The bacterial flagellum is a motile organelle composed of thousands of protein subunits. The filamentous part that extends from the cell membrane is called the axial structure and consists of three major parts, the filament, hook, and rod, and other minor components.

77. A bacterium with a tuft of flagella at both poles is called:

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

Explanation: OPTION A: A lophotrichous bacterium has a group of two or more flagella inserted at one pole of the cell. OPTION B: In peritrichous bacterium, flagella are dispersed on the entire surface of the cell. OPTION C: A monotrichous bacterium possess a single flagellum. OPTION D: An amphitrichous bacterium is characterized by groups of flagella inserted at both ends of the cell. Hence, D is the correct option.

78. Eukaryotes can't share which of the following structures with prokaryotes?

• A. Cell wall
• B. Genetic material
• C. Cytoplasm
• D. Mitochondria

Explanation: OPTION A: The cell wall is present in both prokaryotes and eukaryotes. OPTION B: DNA is the genetic material present in both prokaryotes and eukaryotes. The DNA in prokaryotic cells is contained in the central area of the cell called the nucleoid. Eukaryotic cells have a well-defined nucleus within which the genetic material is present OPTION C: The cytoplasm is an integral part of both prokaryotic and eukaryotic cells. OPTION D: Prokaryotes lack membrane-bounded organelles i.e. Mitochondria, E.R., Golgi bodies, etc while eukaryotes have membrane-bounded organelles. Hence, D is the correct option.

79. Pilli hollow appendages in bacteria function in?

• A. Motality
• B. Conjugation
• C. Chemical detection
• D. None of above options are correct

Explanation: Option A : Pilli is not involved in motility. Motility is the function of flagella. Option: B Pilli hollow appendages in bacteria function in conjugation. Pilli is primarily involved in the mating process called conjugation. Conjugating bacteria use specialized sex pilli, which are hollow appendages, to transfer genetic material (DNA). Option C : Chemical detection i.e. chemotaxis is the function of flagella.

80. Prokaryotes that can utilize oxygen if available, but do not require it, are called?

• A. Constitutive anaerobe
• B. Facultative anaerobe
• C. Constitutive aerobe
• D. Obligate anaerobe

Explanation: A facultative anaerobe is any organism that is able to produce energy aerobically and ''switch to anaerobic respiration depending on the amounts of oxygen in the environment.''