Free Kingdom Prokaryotae MCQs with Answers

• A. 0.75-1.25 μm
• B. 100-200 nm
• C. 0.1-600 μm
• D. 500 μm

Explanation: The correct answer is Option D: 500 μm. Spirochetes are known for their unique spiral shape and can vary significantly in size.

• A. Epulopiscium fishelsoni
• B. Pseudomonas aeruginosa
• C. Escherichia coli
• D. Streptococcus pneumoniae

Explanation: The correct answer is Epulopiscium fishelsoni, which is one of the largest known bacteria, reaching lengths up to 0.5 millimeters…

• A. CO2 cycle
• B. Nitrogen cycle
• C. Phosphorus cycle
• D. All of the above

Explanation: Bacteria are indispensable in various biogeochemical cycles. In the carbon cycle, they decompose organic matter, releasing carbon dioxide.

• A. Within nucleolus
• B. Prior to fission
• C. Just before transcription
• D. During S phase

Explanation: In bacteria, DNA replication occurs just prior to binary fission, ensuring that each daughter cell receives a complete set of genetic…

• A. It protects the bacterium from desiccation
• B. Provides pathogenicity to bacteria
• C. It allows bacterium to "hide" from host's immune system
• D. It allows the bacterium to attach to the surface
• E. All

Explanation: A bacterial capsule is advantageous to a bacterium, particularly in terms of pathogenicity, for the following reasons:1.

• A. It forms a bridge between two bacterial cells
• B. It involves the transport of genetic material via vectors
• C. It is a form of sexual reproduction
• D. None of these

Explanation: Bacterial conjugation is a mechanism of horizontal gene transfer where genetic material, typically plasmid DNA, is directly transferred…

• A. Cocci
• B. Bacilli
• C. Spirilla
• D. None of these

Explanation: Spirilla bacteria are also termed curve screw shaped.

• A. Polysaccharides
• B. Cellulose
• C. Amino Acids
• D. Proteins

Explanation: A bacteria consists of glycocalyx- the outermost covering of a bacteria, that exists in two forms i.e., capsule and slime.

• A. Mesosomes
• B. Zygospores
• C. Endospores
• D. Cysts

Explanation: Endospores are dormant bodies that are capable of surviving for longer periods and are resistant to higher temperatures and UV radiations.

• A. Gram positive bacteria
• B. Gram negative bacteria
• C. Both Gram positive & negative
• D. None of these

Explanation: In Gram-negative bacteria, periplasmic space - the space between the peptidoglycan layer of the cell wall and cell membrane which is the…

• A. Polysaccharides
• B. Proteins
• C. Peptidoglycan
• D. Cholesterol

Explanation: Bacterial cell walls are primarily composed of peptidoglycan, which is a unique macromolecule consisting of both sugars (polysaccharides)…

• A. Granules
• B. Cysts
• C. Spores
• D. Plasmids

Explanation: Spores are thick, dormant, and tough structures produced by some bacteria that provide resistance or protection against harsh or adverse…

• A. Mycoplasma
• B. Streplococcus
• C. Escherichia
• D. Bacillus

Explanation: These bacteria lack a cell wall and are among the tiniest free-living organisms.

• A. Spirochete
• B. Ecoli
• C. Pseudomonas
• D. Campylobacter

Explanation: Option A: Spirochetes are a diverse group of bacteria that exhibit a helical or spiral shape.

• A. Antonie Van Leeuwenhoek
• B. Robert Koch
• C. Louis Pasteur
• D. Twort

Explanation: Option A is the right answer. Leeuwenhoek first discovered microbes and called them animalcules.

• A. Louis Pasteur
• B. Robert Koch
• C. Christain Gram
• D. None of above

Explanation: Germ Theory states that microorganisms known as pathogens or "germs" can lead to disease.

• A. Diplococcus
• B. Peritrichous
• C. Monotrichous
• D. A tetrad

Explanation: Bacteria can be classified according to the number of flagella on their cell wall, and peritrichous is a type will many flagella all over…

• A. Gram-negative bacteria are more likely to cause systemic effects because they lack an outer membrane which means they can infect host cells more quickly.
• B. Gram-negative bacteria are more likely to cause systemic effects because they have an outer membrane which is supposed to protect them from antibiotics
• C. Both Options A and B are correct
• D. None of these options is correct

Explanation: d) None of these options is correct.This option is the most accurate. Both Option A and Option B have inaccuracies in their statements.

• A. Cube of eight cocci
• B. Square of four cocci
• C. Irregular structure
• D. Triangular 6 cocci

Explanation: Option A is correct since Sarcina is a cube of 8 cocci.

• A. Gram-positive
• B. Gram-negative
• C. Both A and B
• D. None of these

Explanation: Correct option: A (fact) (Gram positive bacteria retain bluish purple dye when being tested).