MCQ on Environmental Microbiology Pdf

• Environmental Microbiology is an area of ​​science dedicated to the study of physiology, genetics, interactions, and functions of microorganisms in the environment, and makes use of this knowledge with the greater objective of maintaining environmental quality and contributing to the sustainable development of modern society.
• Environmental microbiology is an area located within microbiology focused on the study of microorganisms in the environment.
• Environmental microbiology also applies to the maintenance of human health.
• Environmental Microbiology uses to perform decontamination, Bioremediation, and Pollution Control.
• It is also used to develop and test methods of cultivation and application of microorganisms.
• Environmental microbiologists study how microorganisms interact with the environment and each other.
• Applications of environmental microbiology include water quality modeling, pollution control, and process design of water and wastewater treatment operations. (MCQ on Environmental Microbiology)

MCQ on Environmental Microbiology Pdf

Q1. Most of the microorganisms
A) is a protozoan
B) Help to improve the quality of life
C) Live at the bottom of the ocean
D) Found in outer space
Correct Answer: B
Explanation: Many microorganisms play beneficial roles such as decomposing waste, fixing nitrogen, and aiding digestion, thus improving life quality.

Q2. A phage is a virus that infects
A) Yeast
B) Fungus
C) Bacteria
D) Protozoa
Correct Answer: C
Explanation: Bacteriophages, or phages, are viruses that specifically infect and replicate within bacteria.

Q3. The special characteristics suitable for all microorganisms are
A) they are multicellular
B) cells with distinct nuclei
C) can only be seen with a microscope
D) capable of photosynthesis
Correct Answer: C
Explanation: Most microorganisms are microscopic and require a microscope to be observed.

Q4. __________ is a common unit of microbial size
A) mm
B) μm
C) cm
D) nm
Correct Answer: B
Explanation: Micrometers (μm) are commonly used to measure microbial size like bacteria and protozoa.

Q5. The main mode of reproduction of bacteria is
A) fission
B) budding
C) proliferation
D) We are all
Correct Answer: A
Explanation: Most bacteria reproduce asexually by binary fission, a process where one cell splits into two identical cells.

Q6. The moisture contained in clouds and precipitated as snow, hail, rain, etc. constitutes
A) Atmospheric water
B) Surface water
C) Groundwater
D) Subterranean water
Correct Answer: A
Explanation: Atmospheric water includes all moisture present in the atmosphere and precipitation.

Q7. Among the following, the microorganism that belongs to Gram-negative bacteria is
A) Escherichia coli
B) Staphylococcus aureus
C) Bacillus megaterium
D) Pneumococcus
Correct Answer: A
Explanation: Escherichia coli is a well-known Gram-negative bacterium.

Q8. Which of the following molds can produce zoospores?
A) Pythium
B) Mucor
C) Gibberella
D) Penicillium
Correct Answer: A
Explanation: Pythium is an oomycete mold that produces motile zoospores.

Q9. Nitric acid bacteria rely on ____ to produce energy.
A) Fermentation
B) Aerobic respiration
C) Anaerobic respiration
D) Photophosphorylation
Correct Answer: B
Explanation: Nitrifying bacteria like Nitrobacter use aerobic respiration to oxidize nitrogen compounds.

Q10. The suitable pH for yeast growth is
A) 5.0–6.0
B) 3.0–4.0
C) 8.0–9.0
D) 7.0–7.5
Correct Answer: A
Explanation: Yeasts thrive in slightly acidic environments, typically between pH 5 and 6.

Q11. The chemical substrate for further metabolism in the tricarboxylic acid cycle is
A) Ethanol
B) Pyruvate
C) Acetyl CoA
D) Adenosine triphosphate
Correct Answer: C
Explanation: Acetyl CoA enters the TCA (Krebs) cycle to produce energy.

Q12. All the following features apply to cytosine and thymine, except
A) Both are nitrogenous bases
B) Both are pyrimidine molecules
C) Both are found in RNA
D) Both are found in DNA
Correct Answer: C
Explanation: Thymine is not found in RNA; uracil replaces it.

Q13. The one who studies the relationship between different microbial communities and their environment is
A) Microbial evolution
B) Microbial physiology
C) Microbial ecology
D) Microbial biochemical microbiology
Correct Answer: C
Explanation: Microbial ecology focuses on interactions between microbes and their environment.

Q14. The main product of the ammoniation process in the soil is
A) Urea
B) Amino acids
C) Protein
D) Ammonia
Correct Answer: D
Explanation: Ammonification converts organic nitrogen into ammonia.

Q15. The most commonly used medium for culturing bacteria in the laboratory is
A) Beef extract, peptone medium
B) Potato medium
C) Gao’s No.1 medium
D) Wort medium
Correct Answer: A
Explanation: Nutrient broth and agar containing beef extract and peptone are standard for bacterial culture.

Q16. The hyphae of actinomycetes with nutrient absorption and metabolite excretion functions are
A) Basal mycelium
B) Aerial mycelium
C) Spore silk
D) Spores
Correct Answer: A
Explanation: Basal mycelium helps in nutrient absorption from the substrate.

Q17. The following microorganism is an archaea
A) Methanogens
B) Actinomycetes
C) Nitrogen-fixing bacteria
D) Cyanobacteria
Correct Answer: A
Explanation: Methanogens are archaea that produce methane under anaerobic conditions.

Q18. Microorganisms survive in arid environments because of
A) Spore formation
B) Metabolizing only glucose
C) No cell membrane
D) No chromosomes
Correct Answer: A
Explanation: Spore formation allows microorganisms to survive in harsh, dry environments.

Q19. The following dyes are used in Gram staining
A) Methylene blue and Congo red
B) Aniline black and carbolic acid fuchsia
C) Saffron and crystal violet
D) Congo red and crystal violet
Correct Answer: C
Explanation: Crystal violet and safranin are primary and counter stains in Gram staining.

Q20. The types of nutrients that provide energy by oxidizing inorganic substances are
A) Photoautotroph
B) Chemoautotroph
C) Photoheterotroph
D) Chemoheterotroph
Correct Answer: B
Explanation: Chemoautotrophs derive energy from inorganic chemical reactions.

Q21. Which of the following statements about growth factors is incorrect?
A) Growth factors are organic or inorganic substances that cannot be synthesized by microorganisms but are necessary
B) Different microorganisms may require different growth factors
C) The same microorganism may have different requirements for growth factors under different growth conditions
D) Growth factors include amino acids, bases, and vitamins
Correct Answer: A
Explanation: Growth factors are only organic substances (not inorganic) required in trace amounts.

Q22. This microbe is the most common agent causing illness linked to recreational water:
A) Pseudomonas aeruginosa
B) Shigella
C) Cryptosporidium parvum
D) Toxoplasma gondii
Correct Answer: C
Explanation: Cryptosporidium is a chlorine-resistant protozoan that causes diarrheal disease from contaminated recreational water.

Q23. What chemical contaminant can be acted upon by microbes to produce a lethal nerve toxin?
A) Copper
B) Mercury
C) Lead
D) Fluoride
Correct Answer: B
Explanation: Mercury can be converted by microbes into methylmercury, a potent neurotoxin.

Q24. All the following are true of potable water except
A) It is drinkable
B) It contains dissolved substances
C) It is void of microbes
D) It contains chemicals
Correct Answer: C
Explanation: Potable water may contain safe levels of non-pathogenic microbes, so it is not completely microbe-free.

Q25. This organism survives in hot tubs and causes dermatitis:
A) Legionella pneumoniae
B) Leptospira
C) Giardia lamblia
D) Pseudomonas aeruginosa
Correct Answer: D
Explanation: Pseudomonas aeruginosa is thermotolerant and can cause “hot tub rash.”

Q26. Sources of contamination of aquifers and groundwater include
A) Broken sewer lines
B) Fertilizers on farmland
C) Defective well casing
D) All of the above
Correct Answer: D
Explanation: All listed sources can lead to groundwater contamination.

Q27. The correct order of steps in sewage water treatment is
A) 2, 3, 1, 4, 5
B) 4, 2, 3, 1, 5
C) 3, 4, 5, 1, 2
D) 2, 5, 4, 3, 1
Correct Answer: D
Explanation: The typical order involves sedimentation (holding ponds), sludge removal, chemical treatment, filtration, and disinfection.

Q28. The most common organism used as an indicator of fecal contamination is
A) Escherichia coli
B) Staphylococcus aureus
C) Acanthamoeba
D) Vibrio cholerae
Correct Answer: A
Explanation: E. coli is a standard indicator organism for detecting fecal contamination in water.

Q29. This method can detect microorganisms and viruses on membrane filters:
A) Chlorination of filter
B) Cultivation using lactose broth
C) Streaking on EMB plate
D) Using polymerase chain reaction (PCR)
Correct Answer: D
Explanation: PCR is a sensitive technique that can detect minute quantities of microbial DNA.

Q30. This group of microbes aids anaerobic carbon degradation during sewage treatment:
A) Coliforms
B) Lactose-producing organisms
C) Photosynthetic organisms
D) Gram-positive organisms
Correct Answer: C
Explanation: Photosynthetic microbes play a role in breaking down organic matter anaerobically during sewage treatment.

True or False

1. A prophage is a DNA fragment integrated into the host DNA, and it cannot reproduce independently.
Answer: False

2. The abnormal morphology of bacteria is an inherent characteristic of bacteria.
Answer: True

3. Eukaryotic microorganisms can grow at high temperatures than prokaryotic microorganisms.
Answer: False

4. Spores are the reproductive organs of spore bacteria.
Answer: False

5. Both photosynthetic bacteria and cyanobacteria are phototrophic microorganisms that produce oxygen.
Answer: False

6. The polysaccharide used to solidify the bacterial culture medium is agar.
Answer: True

7. During the decay period of microbial growth, the rate of cell death exceeds the rate of cell division.
Answer: True

8. The bases adenine, guanine, and cytosine exist in RNA or DNA, but only RNA has thymine.
Answer: False

9. The optimum growth conditions for fungi are somewhat alkaline.
Answer: False

10. All nutrients that affect the growth rate of microorganisms are called growth-limiting factors.
Answer: False