Chapter Exam

Chapter 9: Environmental Microbiology — Online MCQ Test

Q: What is the primary indicator organism used in water quality testing for fecal contamination?

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.

Q: Which of the following is a strategy used to clean up oil spills using microorganisms?

Answer: B. Bioremediation — Bioremediation is the process where microorganisms are used to degrade environmental pollutants like oil spills.

Q: What does MPN stand for in the context of water microbiology?

Answer: B. Most Probable Number — MPN (Most Probable Number) is a statistical method used to estimate the concentration of viable microorganisms in a sample.

Q: In the context of the MPN test, what indicates a positive reaction in the presumptive stage?

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.

MICROBIOLOGY · CLASS 11th · Tamil Nadu State Board

Practice Chapter 9: Environmental Microbiology with a free chapter-wise online MCQ test for Tamil Nadu State Board CLASS 11th MICROBIOLOGY. 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.

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Chapter 9: Environmental Microbiology — Important Questions & Answers (FAQ)

Frequently asked questions from Tamil Nadu State Board CLASS 11th MICROBIOLOGY — Chapter 9: Environmental Microbiology, with answers and explanations. These are sample questions; the exam has its own separate question set.

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.

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.

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.

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.

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.

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Chapter 10: Soil Microbiology