Free Biodiversity and Variety of Life MCQs with Answers

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

Explanation: The exponential or the log phase is the phase during which the bacterium increases the most rapidly as shown in the figure below:

• A. Saprotrophic bacteria
• B. Parasitic bacteria
• C. Cyanobacteria
• D. Pathogenic bacteria

Explanation: The answer is tiny organisms known as cyanobacteria or blue-green algae.

• A. It has cell wall
• B. It has cytoplasm
• C. It has genetic material
• D. All of the above

Explanation: A typical bacterium has all the structures listed from opinion A-C, including cell wall, cytoplasm and genetic material.

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

Explanation: Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis.

• 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.

• 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.

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

Explanation: Treponema Pallidum causes a disease called Syphilis.

• 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…

• 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.

• 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.

• 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.

• 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.

• 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.

• A. Nucleolus
• B. Centrosome
• C. Nucleoid
• D. Nucleus

Explanation: Bacterial chromosomes are located in a nucleoid, a distinct cytoplasmic structure, in which double-stranded DNA is coated with…

• A. Mesosomes
• B. Zygospores
• C. Endospores
• D. Hyphae

Explanation: Numerous strategies exist in bacteria to cope with stressful conditions including the formation of endospores.

• A. Centrosomes
• B. Mesosomes
• C. Dictyosomes
• D. Polysomes

Explanation: Mesosomes or chondroids are folded invaginations in the plasma membrane of bacteria.

• A. Gram-positive bacteria
• B. Gram-negative bacteria
• C. Both Gram-negative and positive bacteria
• D. None of these options are correct

Explanation: Gram-negative bacteria have an outer layer (membrane) that protects them from their environment.

• A. Spherical
• B. Spring
• C. Rod
• D. Screw
• E. Comma

Explanation: Coccus, plural Cocci, in microbiology, a spherical-shaped bacterium.

• A. Cocci
• B. Bacilli
• C. Spirilla
• D. Commas

Explanation: Bacteria are classified according to their shape, or morphology. Spherical bacteria are known as cocci, rod-shaped bacteria are bacilli…

• A. Cellular anaerobe
• B. Respiratory anaerobe
• C. Obligate anaerobe
• D. Facultative anaerobe

Explanation: Facultative anaerobes are bacteria that can grow in both the presence or absence of oxygen.