Question

The most common indicator organism that represents polluted water is

• A. C. vibrio
• B. Entamoeba histolytica
• C. E.coli
• D. P.typhi.

Answer 1

The Correct Option is C

The question pertains to identifying the most common indicator organism for polluted water, and the options are C. vibrio, Entamoeba histolytica, E.coli, and P.typhi. Let's analyze each option to determine the correct answer:

1. C. vibrio: This refers to Vibrio cholerae, which is a bacterium known to cause cholera. While it is a pathogen, it is not commonly used as a general indicator of water pollution.
2. Entamoeba histolytica: This is a protozoan parasite responsible for amoebic dysentery. Like C. vibrio, it is important for specific disease monitoring but not as a general indicator of water quality.
3. E.coli: Escherichia coli is a bacterium that is part of the normal flora of the human gut. Its presence in water is a key indicator of fecal contamination and general water pollution. It is widely used as an indicator organism in assessing water quality.
4. P.typhi: Salmonella typhi causes typhoid fever. Although it is a significant pathogen, it is not typically used as an indicator for general water pollution.

Based on this analysis, E.coli is the best choice as the most common indicator organism of water pollution. It is frequently used in water quality tests to detect possible contamination with fecal material, which could carry various pathogens.

Conclusion: The correct answer is E.coli, as it serves as a standard indicator for measuring the bacterial contamination level in water, particularly for fecal pollution.