Free Kingdom Prokaryotae MCQs with Answers

301. In Cyanobacteria, All these structures are present except:

• A. Glycogen
• B. Akinetes
• C. Phycobilins
• D. Jelly like mass with numerous filaments

Explanation: Cyanobacteria are a group of photosynthetic bacteria that possess various structures and forms. Some common structures found in cyanobacteria include: Filaments: Cyanobacteria often form filamentous structures, where individual cells are connected in a chain-like arrangement. These filaments can be unicellular or multicellular. Unicellular Forms: Some cyanobacteria exist as individual cells or colonies of cells that do not form filaments. Heterocysts: Certain cyanobacteria possess specialized cells called heterocysts. Heterocysts are involved in nitrogen fixation, converting atmospheric nitrogen into a form that can be utilized by the organism. Sheaths: Cyanobacteria may secrete protective sheaths around their filaments. These sheaths provide structural support and protection. However, a "jelly-like mass" is not a typical characteristic of cyanobacteria. Cyanobacteria are primarily characterized by their filamentous or unicellular forms, along with the presence of specialized structures like heterocysts and sheaths.

302. It is usually found in bacteria:

• A. Cell wall
• B. Slime
• C. Chromatin bodies
• D. Mesosome

Explanation: The correct option is D) Mesosome. Mesosomes are usually found in bacteria. They are invaginations or infoldings of the plasma membrane, which are associated with various cellular processes, such as cell division and respiration.

303. Misuse of tetracycline and its related compounds cause:

• A. Deafness
• B. Death
• C. Allergic reactions
• D. Discoloration of teeth in young children

Explanation: Misuse of tetracycline and its related compounds can lead to the discoloration of teeth in young children. Tetracycline can bind to developing teeth and cause permanent yellow-brown discoloration.Tetracyclines can have side effects, especially when used inappropriately or without a healthcare provider's guidance. Common side effects include gastrointestinal issues, photosensitivity (increased sensitivity to sunlight), and potential effects on developing teeth and bones in children and fetuses.

304. When cocci are arranged irregularly, like clusters of grapes, the arrangement is called:

• A. Streptococcus
• B. Sarcina
• C. Tetracoccus
• D. Staphylococcus

Explanation: When cocci are arranged irregularly, like clusters of grapes, the arrangement is called Staphylococcus. The term "staphylococcus" comes from the Greek words "staphyle" (meaning "grape") and "coccus" (meaning "berry" or "coccus"), which accurately describes the cluster-like appearance of the bacteria.

305. These are rod-shaped bacteria:

• A. Cocci
• B. Vibrio
• C. Bacilli
• D. Spirochaete

Explanation: Bacilli is plural of bacillus which means rod shaped bacterium. Rod-shaped bacteria, also known as bacilli (singular: bacillus), are a common bacterial morphology characterized by elongated and cylindrical cell shapes. They are one of the three main bacterial cell shapes, along with cocci (spherical) and spirilla (spiral). Bacilli can vary in length.

306. When rod-shaped bacteria occur in pairs then the arrangement of cells is known as?

• A. Diplobacillus
• B. Bacillus
• C. Streptobacillus
• D. Staphylobacillus

Explanation: It is a consequence of single division and daughter cells remain attached after division. When rod-shaped bacteria occur in pairs, the arrangement of cells is known as "diplobacilli." In this arrangement, two rod-shaped bacterial cells are arranged side by side, forming a pair or diplo configuration. Diplobacilli are a specific type of bacterial cell arrangement and can be a characteristic feature used in the identification and classification of bacteria. The term "diplo" is derived from the Greek word "diploos," meaning double or twofold.

307. Spirals come in one of the three forms which are:

• A. Vibrio, curved or comma-shaped
• B. Spirochaete, curved or comma-shaped
• C. Spirillum, curved or comma-shaped
• D. Vibrio, Spirillum or Spirochaete shaped

Explanation: Spiral-shaped bacteria exist in three forms which are spirally coiled bacteria: Vibrio is a comma-shaped or curved bacterium. Spirillum is a helical bacterium with thin and flexible walls Spirochete is a helical bacterium with thick and rigid walls.

308. These are extremely thin, hair-like appendages of bacteria:

• A. Attachment
• B. Fimbriae
• C. Sex pili
• D. Flagella

Explanation: Flagella are extremely thin hair like appendages, whereas pili are non-helical, filamentous appendages. Pili are smaller than flagella and are not involved in motility. They act as sex pili to make a conjugation tube on one hand and act as organ of attachment on other hand. An attachment pilus is also called fimbria.

309. When coccus divides in three planes, it will produce a:

• A. Sarcina
• B. Tetrad
• C. Streptococcus
• D. Staphylococcus

Explanation: When cocci divides in three plane it forms cube of 8 cocci or sarcina. Sarcina is a genus of bacteria characterized by their distinctive cuboidal, packet-like, or tetrad arrangement of cells. These bacteria are Gram-positive and usually occur in groups of four, eight, or more cells that remain attached and divide in multiple planes, forming a compact and regular arrangement. The name "Sarcina" is derived from the Latin word for "package" or "bundle."

310. These bacteria very rarely have flagella:

• A. Cocci
• B. Bacilli
• C. Spirilli
• D. Repulsion

Explanation: Cocci bacteria, which are characterized by their spherical or ovoid shape, typically do not have flagella. Flagella are long, whip-like appendages that bacteria use for motility. Instead, cocci bacteria usually lack flagella and rely on other means of locomotion or remain non-motile. Their small, rounded shape is not conducive to the typical spiral or rod-shaped bacteria with flagella that use these structures for movement.