Chapter 9: Environmental Microbiology — Online MCQ Test
MICROBIOLOGY · CLASS 11th · Tamil Nadu State Board
Practice Chapter 9: Environmental Microbiology with a free chapter-wise online MCQ test.
This chapter covers: This chapter explores microbial roles in aquatic air and terrestrial environments. Students study sewage treatment biofouling bioindicators water quality testing MPN test and biore....
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 9: Environmental Microbiology — Important Questions & Answers
What is the primary indicator organism used in water quality testing for fecal contamination?
- A. Escherichia coli
- B. Bacillus subtilis
- C. Staphylococcus aureus
- D. Streptococcus pneumoniae
Answer: A. Escherichia coli
E. coli is the standard indicator organism for fecal contamination in water because it is abundant in the intestines of warm-blooded animals.
E. coli is the standard indicator organism for fecal contamination in water because it is abundant in the intestines of warm-blooded animals.
Which of the following is a strategy used to clean up oil spills using microorganisms?
- A. Bioleaching
- B. Bioremediation
- C. Bioaugmentation
- D. Biofouling
Answer: B. Bioremediation
Bioremediation is the process where microorganisms are used to degrade environmental pollutants like oil spills.
Bioremediation is the process where microorganisms are used to degrade environmental pollutants like oil spills.
What does MPN stand for in the context of water microbiology?
- A. Maximum Probable Number
- B. Most Probable Number
- C. Minimum Possible Nitrogen
- D. Microbial Population Norm
Answer: B. Most Probable Number
MPN (Most Probable Number) is a statistical method used to estimate the concentration of viable microorganisms in a sample.
MPN (Most Probable Number) is a statistical method used to estimate the concentration of viable microorganisms in a sample.
Comparing soil microbial populations at different depths, which statement is most accurate?
- A. Microbial counts are highest in the B-horizon
- B. Microbial counts are highest in the topsoil (A-horizon)
- C. Microbial distribution is uniform throughout all soil layers
- D. Microbes are absent in deep soil horizons
Answer: B. Microbial counts are highest in the topsoil (A-horizon)
The topsoil (A-horizon) is rich in organic matter and oxygen, providing the most favorable conditions for microbial growth.
The topsoil (A-horizon) is rich in organic matter and oxygen, providing the most favorable conditions for microbial growth.
In the context of the MPN test, what indicates a positive reaction in the presumptive stage?
- A. Growth and acid production
- B. Production of gas in lactose broth
- C. Change in color to deep red
- D. Formation of a clear precipitate
Answer: B. Production of gas in lactose broth
The presumptive test for coliforms is based on the fermentation of lactose with the production of gas within 24-48 hours.
The presumptive test for coliforms is based on the fermentation of lactose with the production of gas within 24-48 hours.