[50+] Microbiology MCQs & Answers {PDF} For NTS, NET, SSB, SSC, IBPS, RRB, Govt. Exams

1. Bacteria
2. Fungi
3. Protozoa
4. Viruses

Ans. A

Bacteria are prokaryotic organisms because they lack a true nucleus and membrane-bound organelles.

1. Kill human cells
2. Kill viruses
3. Kill bacteria
4. Enhance the immune system

Ans. C

Antibiotics are drugs used to kill or inhibit the growth of bacteria.

1. Streptococcus
2. Escherichia coli
3. Mycobacterium tuberculosis
4. Candida albicans

Ans. C

Mycobacterium tuberculosis is the bacterium that causes tuberculosis.

1. Carry oxygen
2. Phagocytosis
3. Produce insulin
4. Transport nutrients

Ans. B

White blood cells perform phagocytosis, which is the process of engulfing and destroying pathogens.

1. Contaminated food and water
2. Airborne droplets
3. Sexual contact
4. Mosquito bites

Ans. C

HIV is primarily transmitted through sexual contact and through exposure to infected blood or bodily fluids.

1. Hepatitis B
2. Malaria
3. Influenza
4. Chlamydia

Ans. D

Chlamydia is a common sexually transmitted infection.

1. Attack healthy cells
2. Recognize pathogens
3. Produce insulin
4. Transport oxygen

Ans. B

Antibodies recognize and bind to specific pathogens, marking them for destruction by immune cells.

1. Protein
2. Cell
3. Atom
4. Virus

Ans. B

A cell is the smallest unit of life capable of performing all life processes.

1. Archaea
2. Fungi
3. Algae
4. Protozoa

Ans. B

Fungi, such as yeast, are used in the fermentation of beer and bread.

1. Mosquitoes
2. Fleas
3. Ticks
4. Flies

Ans. A

Malaria is primarily transmitted through the bite of infected mosquitoes.

1. Streptococcus
2. Borrelia burgdorferi
3. Clostridium botulinum
4. Salmonella

Ans. B

Lyme disease is caused by the bacterium Borrelia burgdorferi, transmitted through ticks.

1. Protein synthesis
2. Energy production
3. Cell division
4. Post-translational modification and packaging of proteins

Ans. D

The Golgi apparatus processes and packages proteins for transport within and outside the cell.

1. Staphylococcus aureus
2. Escherichia coli
3. Streptococcus pyogenes
4. Bacillus anthracis

Ans. B

Escherichia coli is a Gram-negative bacterium, as it does not retain crystal violet stain in the Gram staining process.

1. Hepatitis C
2. Influenza
3. Tuberculosis
4. Malaria

Ans. B

Influenza is a viral disease that affects the respiratory system, causing flu symptoms.

1. Kill the virus
2. Boost the immune system
3. Prevent viral replication
4. Enhance bacterial growth

Ans. C

Antiviral drugs work by preventing viral replication within host cells.

1. Staphylococcus aureus
2. Haemophilus influenzae
3. Streptococcus pyogenes
4. Klebsiella pneumoniae

Ans. C

Streptococcus pyogenes is the bacterium responsible for causing strep throat.

1. Sexual contact
2. Contaminated food and water
3. Respiratory droplets
4. Injection drug use

Ans. D

Hepatitis B is primarily transmitted through exposure to infected blood and body fluids, such as through injection drug use.

1. Mosquitoes
2. Fleas
3. Ticks
4. Bedbugs

Ans. A

Zika virus is primarily transmitted through the bite of infected mosquitoes, specifically Aedes mosquitoes.

1. Streptococcus pneumoniae
2. Lactobacillus acidophilus
3. Pseudomonas aeruginosa
4. Salmonella enterica

Ans. B

Lactobacillus acidophilus is used in the fermentation of yogurt.

1. HIV/AIDS
2. Creutzfeldt-Jakob disease
3. Tuberculosis
4. Malaria

Ans. B

Creutzfeldt-Jakob disease is a neurodegenerative disease caused by prions.

1. Nucleus
2. Mitochondrion
3. Ribosome
4. Endoplasmic reticulum

Ans. B

Mitochondria are the powerhouses of the cell and are responsible for ATP production.

1. Fermentation
2. Photosynthesis
3. Respiration
4. Translation

Ans. A

Fermentation is the process in which yeast converts sugar into alcohol and carbon dioxide.

1. Innate immunity
2. Passive immunity
3. Active immunity
4. Natural immunity

Ans. C

Vaccination leads to active immunity, where the body produces its own antibodies against specific pathogens.

1. Magnetic resonance imaging (MRI)
2. Electrocardiogram (ECG)
3. Gram staining
4. Physical examination

Ans. C

Gram staining is a common method used to identify and differentiate bacteria in clinical samples.

1. Gonorrhea
2. Hepatitis A
3. Ringworm
4. Malaria

Ans. A

Gonorrhea is a bacterial sexually transmitted infection.

1. Rhinovirus
2. Streptococcus pneumoniae
3. Candida albicans
4. Plasmodium falciparum

Ans. A

The common cold is typically caused by rhinoviruses.

1. Tuberculosis
2. Leprosy
3. Athlete’s foot
4. HIV/AIDS

Ans. C

Athlete’s foot is a common fungal infection of the skin on the feet.

1. Archaea
2. Bacteria
3. Viruses
4. Protozoa

Ans. B

Certain bacteria, such as Rhizobium, are responsible for nitrogen fixation in the soil.

1. Sexual contact
2. Airborne transmission
3. Direct contact with blood or bodily fluids
4. Food and water contamination

Ans. C

Ebola virus is primarily transmitted through direct contact with infected blood or bodily fluids.

1. Streptococcus mutans
2. Escherichia coli
3. Salmonella enterica
4. Clostridium difficile

Ans. A

Streptococcus mutans is a bacterium associated with the formation of dental cavities.

1. Endoplasmic reticulum
2. Lysosome
3. Peroxisome
4. Golgi apparatus

Ans. C

Peroxisomes are involved in detoxifying harmful substances in the cell.

1. Hepatitis A
2. Measles
3. Rabies
4. Cholera

Ans. C

Rabies is a viral disease that affects the nervous system and is usually transmitted through animal bites.

1. Synthesis of proteins
2. Cell division
3. Cellular respiration
4. Movement

Ans. D

Cilia and flagella are primarily responsible for cell movement in microbial cells.

1. Common cold
2. Malaria
3. Hepatitis
4. Tuberculosis

Ans. C

Hepatitis is a group of viral infections that primarily affect the liver.

1. Streptococcus pyogenes
2. Salmonella bacteria
3. Candida albicans
4. Plasmodium falciparum

Ans. B

Salmonella bacteria are a common cause of food poisoning when food is contaminated.

1. Vaccination
2. Proper hand hygiene
3. Overuse of antibiotics
4. Disinfecting surfaces

Ans. B

Proper hand hygiene and responsible antibiotic use are key in preventing the spread of antibiotic-resistant bacteria.

1. Invasion
2. Immunity
3. Respiration
4. Photosynthesis

Ans. A

Invasion is the process by which a pathogen enters a host and establishes infection.

1. Mosquitoes
2. Fleas
3. Ticks
4. Bedbugs

Ans. A

Malaria is primarily transmitted through the bite of infected mosquitoes.

1. Herpes simplex virus
2. Chlamydia trachomatis
3. Syphilis
4. Gonorrhea

Ans. C

Syphilis is a bacterial STI that can cause genital ulcers.

1. Binary fission
2. Transformation
3. Conjugation
4. Endocytosis

Ans. C

Conjugation is the process by which bacteria transfer genetic material to other bacteria via direct cell-to-cell contact.

1. Bacteria
2. Viruses
3. Fungi
4. Archaea

Ans. C

Fungi, particularly Penicillium, are used in the production of antibiotics like penicillin.

1. Infection
2. Photosynthesis
3. Metabolism
4. Immunity

Ans. A

Infection is the process by which a microorganism or virus enters a host and causes disease.

1. Direct contact with urine
2. Respiratory droplets
3. Sexual contact and blood exposure
4. Ingesting contaminated food

Ans. C

HIV is primarily transmitted through sexual contact and exposure to infected blood or bodily fluids.

1. Bacteria
2. Fungi
3. Viruses
4. Protozoa

Ans. A

Bacteria, especially Escherichia coli, are the most common cause of urinary tract infections.

1. T lymphocytes
2. B lymphocytes
3. Neutrophils
4. Monocytes

Ans. C

Neutrophils are the white blood cells responsible for phagocytosis, which involves engulfing and digesting pathogens.

1. Flagellum
2. Cell wall
3. Plasmid
4. Capsule

Ans. D

A bacterial capsule is a protective structure that helps bacteria evade the immune system and antibiotics.

1. Inhibition of cell wall synthesis
2. Disruption of DNA replication
3. Inhibition of protein synthesis
4. Interference with fungal cell membrane integrity

Ans. D

Antifungal medications primarily target fungal cell membranes to disrupt their integrity.

1. Pathogenicity
2. Phagocytosis
3. Virulence
4. Antimicrobial resistance

Ans. D

Antimicrobial resistance is the process of microorganisms becoming resistant to antimicrobial drugs.

1. Streptococcus mutans
2. Escherichia coli
3. Salmonella enterica
4. Clostridium difficile

Ans. A

Streptococcus mutans is a bacterium associated with the formation of dental cavities.

1. Mosquitoes
2. Fleas
3. Ticks
4. Flies

Ans. A

West Nile virus is primarily transmitted to humans through the bite of infected mosquitoes.

1. Photosynthesis
2. Endocytosis
3. Lysis
4. Viral replication

Ans. B

Endocytosis is the process by which a virus enters a host cell to take over cellular machinery for replication.

1. Airborne transmission
2. Sexual contact
3. Contaminated food and water
4. Direct contact with infected animals

Ans. B

HPV is primarily transmitted through sexual contact.

1. Toxoplasmosis
2. Trichinosis
3. Scabies
4. Filariasis

Ans. B

Trichinosis is a parasitic infection caused by Trichinella spiralis and can be transmitted through undercooked pork.

1. Kill the virus
2. Boost the immune system
3. Prevent viral replication
4. Enhance bacterial growth

Ans. C

Antiviral drugs work by preventing viral replication within host cells.

1. Cell membrane
2. Cytoplasm
3. Cell wall
4. Nucleus

Ans. C

Antibiotics like penicillin target the bacterial cell wall, weakening the cell’s structural integrity.

1. Ribosome
2. Nucleoid
3. Pilus
4. Flagellum

Ans. B

The nucleoid is a region within a bacterial cell where genetic information is stored.