Free Kingdom Prokaryotae MCQs with Answers

21. The DNA of the bacterium is present in a distinct region called:

• A. Nucleolus
• B. Centrosome
• C. Nucleoid
• D. Nucleus

Explanation: Bacterial chromosomes are located in a nucleoid, a distinct cytoplasmic structure, in which double-stranded DNA is coated with histone-like proteins.

22. The bacteria can cope in unfavorable condition by producing:

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

Explanation: Numerous strategies exist in bacteria to cope with stressful conditions including the formation of endospores. An endospore is a dormant, tough, non-reproductive structure produced by a small number of bacteria from the Firmicute family. The primary function of most endospores is to ensure the survival of a bacterium through periods of environmental stress.

23. The cell membrane of a bacterial cell often invaginates to produce membranous structures referred to as:

• A. Centrosomes
• B. Mesosomes
• C. Dictyosomes
• D. Polysomes

Explanation: Mesosomes or chondroids are folded invaginations in the plasma membrane of bacteria.

24. Apparently which bacteria is more resistant to antibiotics?

• A. Gram-positive bacteria
• B. Gram-negative bacteria
• C. Both Gram-negative and positive bacteria
• D. None of these options are correct

Explanation: Gram-negative bacteria have an outer layer (membrane) that protects them from their environment. These bacteria can use this membrane to selectively keep antibiotic drugs from entering. Germs get rid of antibiotics using pumps in their cell walls to remove antibiotic drugs that enter the cell. Gram-positive bacteria, those species with peptidoglycan outer layers, are easier to kill - their thick peptidoglycan layer absorbs antibiotics and cleaning products easily.

25. The shape of Cocci bacteria is:

• A. Spherical
• B. Spring
• C. Rod
• D. Screw
• E. Comma

Explanation: Coccus, plural Cocci, in microbiology, a spherical-shaped bacterium.

26. Vibrio cholera is an example of _ type of bacteria.

• A. Cocci
• B. Bacilli
• C. Spirilla
• D. Commas

Explanation: Bacteria are classified according to their shape, or morphology. Spherical bacteria are known as cocci, rod-shaped bacteria are bacilli, and spiral-shaped bacteria are spirilla, and comma shaped bacteria are known as Vibrio.

27. A_ is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent.

• A. Cellular anaerobe
• B. Respiratory anaerobe
• C. Obligate anaerobe
• D. Facultative anaerobe

Explanation: Facultative anaerobes are bacteria that can grow in both the presence or absence of oxygen. In addition to oxygen concentration, the oxygen reduction potential of the growth medium influences bacterial growth. The oxygen reduction potential is a relative measure of the oxidizing or reducing capacity. Obligate anaerobes are those that carry out anaerobic respiration only and can not carry out aerobic respiration even in presence of oxygen. Cellular anaerobes and respiratory anaerobes are terms not used to designate any type of organism.

28. A bacterial cell envelope of mollicutes does not include?

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

Explanation: Mollicutes is a class of bacteria which does not contain cell wall in its cell envelope.While in most of the bacteria the cell envelope comprises of cell membrane and cell wall, mollicutes lack a peptidoglycan cell wall.

29. Who coined the term Animalcule for microorganisms like Bacteria and Protozoa?

• A. Robert Koch
• B. Louis Pasteur
• C. Alexander Fleming
• D. Leeuwenhoek

Explanation: Animalcule ('little animal', from Latin animal + the diminutive suffix -culum) is an old term for microscopic organisms that included bacteria, protozoans, and very small animals. The word was invented by 17th-century Dutch scientist Antonie van Leeuwenhoek to refer to the microorganisms he observed in rainwater.

30. In a bacterial cell, plasma membrane with all things present within it is called:

• A. Cytoplasmic matrix
• B. Cytoplasm
• C. Protoplast
• D. Cell Structure

Explanation: The protoplasm consists of two major divisions in eukaryotes: the cytoplasm, and the nucleoplasm (cell nucleus). The cytoplasm is the eukaryotic cell's jelly-like material. Except for the nucleus it consists of the cytosol, the vesicles, the cytoskeleton, the inclusions and the organelles.