Free Biodiversity and Variety of Life MCQs with Answers

2201. Which of these processes is the means by which a bacterium can directly uptake and incorporate foreign DNA from the environment into its genome?

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

Explanation: Option B is correct since the transformation is the process of transmitting genetic information from one bacterium to another bacterium causing it to transform (change). Option A is incorrect since transduction is the process in which genetic material is transferred from one bacterium to another by a third party which is a bacteriophage. Option C is incorrect since binary fission is the asexual mode of reproduction of bacteria. Option D is incorrect since conjugation is the process of transfer of genetic material from one bacterium to another through a tube called the conjugation tube or cytoplasmic bridge

2202. How much smaller are viruses than bacteria?

• A. 20 to 2000 times
• B. 10 to 1000 times
• C. 500 times
• D. 3000 times

Explanation: Viruses are 10 to 1000 times smaller than the smallest bacteria. The smallest bacteria, mycoplasma has a size of approximately 0.2 - 0.3 μm.

2203. Which of the following will not survive in the presence of oxygen?

• A. Both B and D
• B. Facultative anaerobe
• C. Constitutive aerobe
• D. Obligate anaerobe

Explanation: Obligate Anaerobe organisms cannot survive in the presence of oxygen. It lacks the necessary enzymes and metabolic pathways to utilize oxygen and may even be harmed by it. Obligate anaerobes require an oxygen-free environment to survive.

2204. 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.

2205. 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.

2206. 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.

2207. 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.

2208. 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.

2209. 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.

2210. 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.