Free Kingdom Prokaryotae MCQs with Answers

171. Louis Pasteur made many discoveries in field of:

• A. Microbiology and Genetics
• B. Genetics and Medicines
• C. Microbiology and Medicines
• D. Pathology and Genetics

Explanation: A. Microbiology and Genetics (Incorrect): Louis Pasteur's major discoveries were in microbiology and not specifically in genetics. B. Genetics and Medicines (Incorrect): While Pasteur made significant contributions to medicine, his major discoveries were in microbiology, not genetics. C. (Correct) In the field of microbiology and medicine Pasteur demonstrated that microorganisms cause disease and discovered how to make vaccines from weakened, or attenuated, microbes. He developed the earliest vaccines against fowl cholera, anthrax, and rabies.D. Pathology and Genetics (Incorrect): Pasteur's major contributions were in microbiology and not specifically in genetics or pathology.

172. The division of cocci in three planes results in formation of a:

• A. Tetrad
• B. Sarcina
• C. Grape like clusters
• D. All of the above options are correct

Explanation: Option A; cells in a square arrangement, tetrads.Option B: The cocci are arranged in a cuboidal manner, as the cells are formed by regular cell divisions in three planes. Cocci that divide in three planes and remain in groups cube like groups of eightOption C: Staphylococcus aureus, which usually forms grape-like clusters, has the ability to form regularly arranged cell packets.

173. Some bacteria ranging occasionally a size of 500 µm in length are which of the following?

• A. Escherichia coli
• B. Mycoplasma
• C. Epulopiscium
• D. Spirochetes

Explanation: Some spirochetes occasionally reach 500 micrometres in length.

174. The gram-positive bacteria appear which colour under gram staining?

• A. Purple
• B. Red
• C. Pink
• D. Blue

Explanation: Gram-positive bacteria are bacteria with thick cell walls. In a Gram stain test, these organisms yield a positive result. The test, which involves a chemical dye, stains the bacterium's cell wall purple.

175. Louis Pasteur discovered a vaccine against which disease?

• A. Cowpox
• B. Smallpox
• C. Rabies
• D. HIV

Explanation: In summary, Louis Pasteur discovered the vaccine against rabies (option C), making a groundbreaking contribution to the field of vaccination.

176. The most common waste material produced by bacteria is?

• A. Lactic acid
• B. Urea
• C. Ammonia
• D. Uric acid

Explanation: Lactic acid is indeed a common waste product produced by certain bacteria, particularly lactic acid bacteria, during a specific metabolic process called lactic acid fermentation. In addition, cells contain waste materials that are subsequently excreted. For example, common waste materials are alcohol, lactic acid, and acetic acid.

177. Which of the following scientists developed the vaccine for anthrax?

• A. Edward Jenner
• B. Leeuwenhoek
• C. Alexander Fleming
• D. Louis Pasteur

Explanation: Louis Pasteur developed a vaccine for anthrax in 1881. So opt D is correct.

178. 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

179. 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.

180. 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.