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With respect to Indicator Species, consider the following statements :
1. Decreasing population of Lichen species is an indicator of Nitrogen pollution.
2. Decline in the Salmon population indicates an unclean and not well-connected river ecosystem.
3. Decline in the Rock Agama Lizards population size always indicates an increase in temperature in the environment.
4. Presence of E.Coli in freshwater is an indicator of faecal contamination.
Which of the statements given above are correct ?
  • a)
    1, 3 and 4 only
  • b)
    2, 3 and 4 only
  • c)
    1, 2 and 4 only
  • d)
    1, 2, 3 and 4
Correct answer is option 'C'. Can you explain this answer?
Most Upvoted Answer
With respect to Indicator Species, consider the following statements :...
Decreasing population of Lichen species
- Lichen species are known to be sensitive to air pollution, especially nitrogen pollution.
- Hence, a decrease in their population can be a strong indicator of nitrogen pollution in the environment.
Decline in the Salmon population
- Salmon are considered as indicator species for river ecosystems.
- A decline in their population can suggest that the river ecosystem is not clean and well-connected, affecting the overall health of the ecosystem.
Decline in the Rock Agama Lizards population size
- Rock Agama Lizards are known to be sensitive to temperature changes.
- However, their decline in population size may not always indicate an increase in temperature in the environment, as there could be other factors affecting their population.
Presence of E.Coli in freshwater
- E.Coli is a bacteria found in the intestines of warm-blooded animals and humans, indicating fecal contamination in water bodies.
- Its presence in freshwater is a clear indicator of contamination and potential health risks associated with the water source.
Therefore, statements 1, 2, and 4 are correct as they provide accurate information about indicator species and their role in assessing environmental conditions. Statement 3, however, may not always hold true as the population decline of Rock Agama Lizards could be influenced by various factors other than just temperature.
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Community Answer
With respect to Indicator Species, consider the following statements :...
An indicator species is a species whose presence indicates the presence of a set of other species and whose absence indicates the lack of that entire set of species. An indicator species is any biological species that defines a trait or characteristic of the environment. A conservation practitioner can use an indicator species as a surrogate for overall biodiversity, monitoring the outcomes of management practices by measuring the rise or fall of the population of the indicator species. Lichens are a symbiotic relationship between algae and fungi. The fungus provides shelter for the algae, and the algae provide food for the fungi. Lichens do not have roots; instead, they receive all their nutrients from the atmosphere. Lichens are sensitive to atmospheric pollution such as nitrogen (N) because they receive all their nutrients and water from wet and dry atmospheric deposition (fallout). Nitrogen deposition can increase the load of nutrients. Too much N can harm and kill the algae's chlorophyll, which is used to produce sugars feeding it and the fungi. Certain species of lichen are more tolerant of N than others. Scientists monitor lichen communities. If an increase in N-tolerant species in combination with a decrease in N-sensitive species occurs, this may indicate an increase in atmospheric N deposition. So, Statement 1 is correct.
Salmon have a complex life history with many life stages occupying different habitats. A healthy salmon population requires many different intact habitat types. Salmon is often referred to as an ecological indicator species of wetlands because their success requires a wide variety of healthy habitats. When a river ecosystem is not clean or well-connected, its salmon population will usually decline. So, Statement 2 is correct.
The "Rock Agama Lizards' are found mainly in rocky places and warm spots. They do not generate their own body heat, so they need to seek warmth from external sources, like a warm rock or a sunny spot. They are important in the ecological aspect, as they can indicate which parts of the city are warming. In warmer temperatures, their reproductive rate may increase, leading to a higher population. Conversely, in cooler temperatures, their reproductive rate may decrease, which can lead to a lower population. So, Statement 3 is not correct.
The concentration of faecal coliforms E. coli in freshwater bodies is an indirect indicator of contamination with human and animal excreta. Water contaminated with human and animal excreta poses a serious health risk and is therefore unsuitable for potable supply unless it has been suitably treated. Faecal indicator bacteria, such as E. coli, remain the preferred way of assessing the hygienic quality of water.
So, Statement 4 is correct. 
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With respect to Indicator Species, consider the following statements :1. Decreasing population of Lichen species is an indicator of Nitrogen pollution.2. Decline in the Salmon population indicates an unclean and not well-connected river ecosystem.3. Decline in the Rock Agama Lizards population size always indicates an increase in temperature in the environment.4. Presence of E.Coli in freshwater is an indicator of faecal contamination.Which of the statements given above are correct ?a)1, 3 and 4 onlyb)2, 3 and 4 onlyc)1, 2 and 4 onlyd)1, 2, 3 and 4Correct answer is option 'C'. Can you explain this answer?
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With respect to Indicator Species, consider the following statements :1. Decreasing population of Lichen species is an indicator of Nitrogen pollution.2. Decline in the Salmon population indicates an unclean and not well-connected river ecosystem.3. Decline in the Rock Agama Lizards population size always indicates an increase in temperature in the environment.4. Presence of E.Coli in freshwater is an indicator of faecal contamination.Which of the statements given above are correct ?a)1, 3 and 4 onlyb)2, 3 and 4 onlyc)1, 2 and 4 onlyd)1, 2, 3 and 4Correct answer is option 'C'. Can you explain this answer? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about With respect to Indicator Species, consider the following statements :1. Decreasing population of Lichen species is an indicator of Nitrogen pollution.2. Decline in the Salmon population indicates an unclean and not well-connected river ecosystem.3. Decline in the Rock Agama Lizards population size always indicates an increase in temperature in the environment.4. Presence of E.Coli in freshwater is an indicator of faecal contamination.Which of the statements given above are correct ?a)1, 3 and 4 onlyb)2, 3 and 4 onlyc)1, 2 and 4 onlyd)1, 2, 3 and 4Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for With respect to Indicator Species, consider the following statements :1. Decreasing population of Lichen species is an indicator of Nitrogen pollution.2. Decline in the Salmon population indicates an unclean and not well-connected river ecosystem.3. Decline in the Rock Agama Lizards population size always indicates an increase in temperature in the environment.4. Presence of E.Coli in freshwater is an indicator of faecal contamination.Which of the statements given above are correct ?a)1, 3 and 4 onlyb)2, 3 and 4 onlyc)1, 2 and 4 onlyd)1, 2, 3 and 4Correct answer is option 'C'. Can you explain this answer?.
Solutions for With respect to Indicator Species, consider the following statements :1. Decreasing population of Lichen species is an indicator of Nitrogen pollution.2. Decline in the Salmon population indicates an unclean and not well-connected river ecosystem.3. Decline in the Rock Agama Lizards population size always indicates an increase in temperature in the environment.4. Presence of E.Coli in freshwater is an indicator of faecal contamination.Which of the statements given above are correct ?a)1, 3 and 4 onlyb)2, 3 and 4 onlyc)1, 2 and 4 onlyd)1, 2, 3 and 4Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for UPSC. Download more important topics, notes, lectures and mock test series for UPSC Exam by signing up for free.
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