Free Biodiversity and Variety of Life MCQs with Answers

2151. Pili are hollow, non helical, filamentous appendages in bacteria. Which one is not true for pili:

• A. They are involved in mating process
• B. They are the means of attachments of bacteria to various surfaces
• C. They are made up of protein
• D. These are present in gram-positive bacteria

Explanation: Pili are a characteristic of Gram-negative bacteria.

2152. When cocci occur in pairs, this arrangement is called _:

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

Explanation: This option is correct because when Bacteria appear in pairs, then it is named as diplococci.

2153. Single-cell of rod-shaped bacteria is called as:

• A. Cocci
• B. Streptobaccilus
• C. Bacillus
• D. Diplobacilli

Explanation: A single rod-shaped bacterium is called a Bacillus.

2154. Spirally coiled bacteria are generally termed as:

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

Explanation: This option is correct because Spirilla (singular, Spirillum) are a group of bacteria characterized by a corkscrew (spiral) appearance. These bacteria are spirally coiled, thick, and rigid.

2155. These all are the functions of flagella in a bacterium, but which is the primary one?

• A. Flagellated bacteria can detect chemicals
• B. The flagellated bacteria moves in response to a chemical signal
• C. Help in motility
• D. On some bacteria, flagella have a role in immunity

Explanation: The primary function of flagella is to aid in the motility of bacteria, allowing them to move through liquid environments.

2156. The bacteria which get their food from dead organic matter are called as:

• A. Heterotrophs
• B. Saprotrophic
• C. Parasitic
• D. Autotrophic

Explanation: This option is correct because Saprotrophic bacteria. known as saprophytic bacteria, are a subset of heterotrophic. bacteria. They obtain their nutrition by decomposing and feeding on dead organic matter, such as decaying plant material or animal remains.

2157. Bacteria that can grow in the absence of oxygen are called as:

• A. Anaerobes
• B. Molds
• C. Aerobes
• D. Yeasts

Explanation: This option is correct because Anaerobic bacteria are microorganisms that can grow and thrive in the absence of oxygen. They can alternative metabolic pathways to generate energy without relying on oxygen.

2158. The process in which we use physical agents to control microorganism is termed as:

• A. Immunization
• B. Sterilization process
• C. Vaccination
• D. Chemical methods

Explanation: This option is correct because Sterilization is the process of using physical or chemical methods to completely eliminate or kill all forms of microorganisms, including bacteria, viruses, and spores, from a surface or substance. It is a method for controlling microorganisms by making an environment completely free of them.

2159. It gives shape to the bacterial cell:

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

Explanation: The cell wall is the structure responsible for giving shape to bacterial cells is a rigid layer that surrounds the cell membrane and provides structural support and protection. The composition of the cell wall varies among different types of bacteria.

2160. Which of the following is not present in bacteria?

• A. Peptidoglycan
• B. rRNA
• C. Histones
• D. Teichoic acid

Explanation: This option is correct because bacteria do not have histones. In contrast to sukaryotic cells, bacterial DNA is not wrapped around histones but is organized in a different manner.