Free Kingdom Prokaryotae MCQs with Answers

11. Tuberculosis is caused by?

• A. Bacterium
• B. Allergy
• C. Nicotine
• D. Virus

Explanation: Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain.

12. Bacteria having a tuft of flagella at one end are called:

• A. Peritrichous
• B. Monotrichous
• C. Lophotrichous
• D. Amphitrichous

Explanation: There are four types of flagellar arrangements based on the number and placement of flagella on the cell. These are, 1. Monotrichous - A single flagellum extends from one end of the cell. 2. Amphitrichous - A single flagellum or multiple flagella extend from two ends of the cell. 3. Lophotrichous - Tuft of flagella extend from one end of the cell. 4. Peritrichous - Multiple flagella randomly distributed over the entire bacterial cell. Thus, the correct answer is 'Lophotrichous.' Option A, B and D are incorrect as their description does not match the requirement of the question i.e. bacteria having a tuft of flagella at one end of the cell.

13. Which one of the following sets includes the bacterial diseases?

• A. Cholera, typhoid, mumps
• B. Tetanus, tuberculosis, measles
• C. Malaria, mumps, poliomyelitis
• D. Diphtheria, leprosy, plague

Explanation: Cholera is a bacteria infection caused by eating food or drinking water contaminated with Vibrio cholerae. Typhoid fever is caused by Salmonella typhi bacteria. Mumps is a viral disease caused by the mumps virus. Tetanus is bacteria infection caused by Clostridium tetani. Tuberculosis is caused by bacterium Mycobacterium tuberculosis. Measles is caused by virus paramyxovirus. Malaria is a disease caused by Plasmodium parasite. Poliomyelitis is infectious disease caused by the poliovirus. Diphtheria is an infection caused by the Corynebacterium diphtheriae bacterium. Leprosy is caused by bacteria Mycobacterium leprae. Plague is a bacterial infection caused by bacterial strain Yersinia pestis. Thus, the correct answer is 'Diphtheria, Leprosy, Plague.'

14. Spirochaete bacterium Treponema Pallidum causes _.

• A. Gonorrhea
• B. Syphilis
• C. Genital herpes
• D. AIDS

Explanation: Treponema Pallidum causes a disease called Syphilis.

15. Which of the following is not a component of extracellular matrix in bacteria?

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

Explanation: "Bacterial surface and walls are very diverse. Collectively complexes of layer external to the cell protoplasm are called as cell envelope and include capsule, slime and cell wall"

16. What are labelled phases A, B, and C in the below given sigmoidal growth curve?

• A. A: Stationary, B: Log, C: Lag
• B. A: Lag, B: Stationary, C: Log
• C. A: Log, B: Lag, C: Stationary
• D. A: Lag, B: Log, C: Stationary

Explanation: When a graph is plotted taking into consideration time on one hand and growth rate, on the other hand, an S-shaped curve is obtained. It is called the "grand period of growth". This curve mainly shows four phases of growth: 1. Initial slow growth (lag phase). 2. The rapid period of growth (log phase), where maximum growth is seen in a short period. 3. The diminishing phase, where growth will be slow. 4. Stationary phase, where finally growth stops.

17. Genetic recombination in bacteria can occur through:

• A. Conjugation
• B. Transformation
• C. Transduction
• D. All of the above

Explanation: Bacteria increase their genetic diversity through three recombination techniques: transduction, transformation and conjugation.

18. Cysts are not resistant to _ but spores are:

• A. Light
• B. Desiccation
• C. pH
• D. Heat

Explanation: An endospore bacteria can survive a number of harsh conditions such as heat, drying, radiation, and chemicals. Other organisms form spores, but the bacterial spore is generally more heat-resistant and difficult to denature.

19. In which phase of bacterial growth, does division at an exponential rate occur?

• A. Lag phase
• B. Log phase
• C. Stationary phase
• D. Decline phase

Explanation: Bacterial colonies progress through four phases of growth: the lag phase, the log phase, the stationary phase, and the death phase. The generation time, which varies among bacteria, is controlled by many environmental conditions and by the nature of the bacterial species.

20. In many bacteria, the cell wall is enclosed within a slime capsule made up of:

• A. Polysaccharides
• B. Cellulose
• C. Amino acids
• D. Proteins

Explanation: The glycocalyx is an outer coating that covers the outside of the bacterial cell wall. The glycocalyx exists in two forms i.e., capsule and slime. The capsule is a condensed layer that is relatively tightly associated with the underlying cell wall and gives sticky or gummy nature to the cell, whereas, slime is a more loosely attached layer that gives slimy or slippery nature to the cell and can be removed from the cell more easily. Generally, the glycocalyx is made of polysaccharides. However, in some cases, protein can also be present.