Free Biodiversity and Variety of Life MCQs with Answers

2211. In prokaryotic cells, ribosomes are _.

• A. 50S+40S
• B. 60S+40S
• C. 80S
• D. 70S

Explanation: Is wrong because in eukaryotes 40S and 60S subunit s of ribosomes combine to form single subunit 80S

2212. E.coli is an example of which type of bacteria?

• A. Anaerobic
• B. Facultative anaerobic
• C. Aerobic
• D. Obligate aerobic

Explanation: Option B is correct. E. coli is classified as a facultative anaerobe. It uses oxygen and grows by aerobic respiration when it is present and available. It can, however, continue to grow in the absence of oxygen using fermentation or anaerobic respiration.

2213. The flagella originates from which part of the cell?

• A. Basal body
• B. Cell membrane
• C. Cell wall
• D. Capsule

Explanation: Option A is correct as cilia and flagella originate from their basal bodies embedded in the cytoplasm. Basal bodies have the same circular arrangement of microtubule triplets as centrioles. Option B is incorrect as the cell membrane is the structure into which the basal body is embedded. Option C is incorrect since the basal body is embedded in the cell wall and cell membrane. Option D is incorrect since the capsule may cover the cell wall in a bacterial cell, so the basal body becomes embedded in it too.

2214. Which of the following would not be found in a prokaryotic cell?

• A. Mitochondria
• B. RNA
• C. Ribosomes
• D. Plasma membrane

Explanation: Prokaryotes lack cell membrane-bound organelles, they do not contain mitochondria.

2215. The filamentous appendages called pilli are present only on?

• A. Gram-positive bacteria
• B. Gram-negative bacteria
• C. Chemo-synthetic bacteria
• D. None of above

Explanation: Pilli is more common in gram-negative bacteria. Pili are long, filamentous appendages that protrude from the surface of bacteria and are involved in a variety of functions, including adhesion, motility, and conjugation. They are composed of protein subunits and can be involved in pathogenicity by allowing bacteria to attach to host cells and tissues.

2216. The process of recombination in prokaryotes takes place in which of the following ways?

• A. Transformation
• B. Conjugation
• C. Transduction
• D. All of these

Explanation: Based on the explanations provided, the correct answer to the question is option D) All of these. Genetic recombination in prokaryotes can occur through transformation, conjugation, and transduction, allowing for the exchange of genetic material and the spread of advantageous traits among bacterial populations.

2217. The main feature of prokaryotic cell is

• A. Absence of DNA
• B. Absence of nucleus
• C. Absence of cell wall
• D. Absence of plastids

Explanation: Prokaryotic cells have their nucleic material naked in the cytoplasm, so no nuclear envelope present, thus no nucleus.

2218. Chromatin body in prokaryotes can also be termed as

• A. Nuclear body
• B. Nuclear region
• C. Nucleoid
• D. All of Above

Explanation: Prokaryotic chromosomes are naked in the cytoplasm. Chromatin body is the place where it is present and can be termed as all of the following.

2219. Bacteria are capable of sharing genetic materials through the surroundings that can be advantageous in certain environments. This type of gene transmission is an example of which of the following?

• A. Transduction
• B. Transformation
• C. Binary fission
• D. Conjugation

Explanation: Transformation is a process by which bacteria make up and incorporate foreign DNA from their environment.

2220. Which of the following would not be found in an E. Coli sample?

• A. Nuclei
• B. Cell wall
• C. Ribosomes
• D. Plasma membrane

Explanation: 'E. Coli', a bacterium, is a prokaryote that lacks a true nucleus. Instead, they have a nucleoid, the chromosome with its associated proteins and RNA. Options B, C, and D are incorrect since bacterias contain a cell membrane surrounded by the cell wall and ribosomes in the cytoplasm.