Free Biodiversity and Variety of Life MCQs with Answers

• A. Chitin
• B. Murein
• C. Cellulose
• D. Hemicellulose

Explanation: Murein, also known as peptidoglycan, is the main component of bacterial cell walls.

• A. One
• B. Two
• C. Three
• D. Four

Explanation: The Gram-negative cell wall consists of 2 interconnected layers of peptidoglycan surrounded by an outer membrane.

• A. Alcohol, acetic acid and lactic acid
• B. Alcohol, potassium and sulphur
• C. Alcohol, glycogen and phosphate
• D. Glycogen, fat and potassium

Explanation: Prokaryotes mostly keep Alcohol, lactic acid and acetic acid as wastes. Thus, option A is appropriate.

• A. Parasitic bacteria
• B. Saprophytic bacteria
• C. Symbiotic bacteria
• D. Photosynthetic bacteria

Explanation: Saprophytic bacteria are called scavengers of earth because these bacteria decompose dead organic matter and obtain nutrients from…

• A. Condensed
• B. Thick
• C. Moderate
• D. Thin
• E. Entangled

Explanation: In gram-negative bacteria, the peptidoglycan layer is relatively thin compared to gram-positive bacteria.

• A. Norcardia salmonicolor
• B. Hydrogenomonas
• C. Pseudomonas
• D. Thiobacillus
• E. Azobacter

Explanation: The correct answer is Pseudomonas because some species within this genus have the unique ability to oxidize carbon monoxide (CO) as a…

• A. Flagellated rod-shaped bacterium
• B. Flagellated chain bacterium
• C. Flagellated spiral-shaped bacterium
• D. Non-flagellated spiral-shaped bacterium
• E. Non-flagellated rod-shaped bacterium

Explanation: Helicobacter pylori is a flagellated spiral-shaped bacterium. Its spiral shape and flagella help it move through the mucus lining of the…

• A. Aerobic
• B. Anaerobic
• C. Facultative
• D. Microaerophill

Explanation: Aerobic organisms are microorganisms and other living beings that require oxygen for their survival and growth.

• A. After fertilization of gametes
• B. Before spore formation
• C. During binary fission
• D. After binary fission

Explanation: The circular bacterial genome is replicated. The process begins at the origin of replication, where the DNA unwinds and new complementary…

• A. Made up of microfilaments
• B. Contains centriole
• C. Originates from basal bodies
• D. They are immotile

Explanation: Flagella originate from basal bodies, which are protein structures located at the base of these appendages.

• A. Has a short dormant period
• B. Contains moisture for survival
• C. Metabolically active
• D. Endures extreme condition

Explanation: Endospores are incredibly resilient to extreme environmental conditions, including high temperatures, desiccation, radiation, and chemical…

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

Explanation: In this phase, bacteria divide rapidly by binary fission, where each cell splits into two identical daughter cells.

• A. Heterocyst
• B. Lysosomes
• C. Mitochondria
• D. Ribosomes

Explanation: Heterocysts are specialized cells found in certain filamentous cyanobacteria (blue-green algae) that play a critical role in nitrogen…

• A. Campylobacter
• B. E. coli
• C. Pseudomonas
• D. Spirochete

Explanation: Spirochetes are often anaerobic (or microaerophilic) because of the way their metabolism and cellular structure are adapted to…

• A. Acanthurus nigrofuscus
• B. Epulopiscium fishelsoni
• C. Hyphomicrobium
• D. Mycoplasma Spp

Explanation: Acanthurus nigrofuscus, commonly known as the bristletooth tang or brown surgeonfish, is a species of fish belonging to the family…

• A. Antiseptics
• B. Chemotherapeutics
• C. Disinfectants
• D. Vaccines

Explanation: Antiseptics are chemical substances that inhibit the growth of or destroy microorganisms on living tissues, such as skin and mucous…

• A. Amoeba
• B. Bacteria
• C. Protozoa
• D. Virus

Explanation: Peptidoglycan is a complex polymer found in the cell walls of bacteria.

• A. Carry fewer genes than the chromosome
• B. Replicate autonomously from the chromosome
• C. They are considered as genetic elements
• D. The bacterial chromosome depends on plasmids for replication

Explanation: Actually, the bacterial chromosome does not depend on plasmids for replication.

• A. Both gram-negative and positive bacteria
• B. Gram-negative
• C. Gram-positive
• D. Mycobacteria

Explanation: Many Gram-positive bacilli (rod-shaped bacteria), such as Bacillus and Clostridium species, can form endospores, which are highly…

• A. Fungi
• B. Bacteria
• C. Protozoa
• D. Virus

Explanation: Bacteria, specifically Escherichia coli, are used in the production of Humulin (human insulin) through genetic engineering.