345306
Which of the following options is/are incorrect about algal bloom?
1 Formed by blue-green algae and other planktonic algae
2 Causes fish mortality
3 Causes depletion of \(\mathrm{O}_{2}\) in water
4 Biomagnification with DDT causes it
Explanation:
Biomagnification with DDT causes it is incorrect.
BIOXII16: ENVIRONMENTAL ISSUES
345307
Assertion : There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Reason : Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Domestic sewage is rich in biodegradable organic matter and the decomposition of this organic matter by microorganisms requires oxygen. Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. If sewage quantity is large, the whole of dissolved oxygen may be consumed leaving nothing for respiration for fish and other clean water organisms. They, therefore, get killed. However, as sew age is decomposed, there is a gradual rise in dissolved oxygen downstream. Fish and other clean water organisms reappear indicating the recovery of river from sewage discharge.
BIOXII16: ENVIRONMENTAL ISSUES
345308
DDT in zooplanktons is in ____ concentration
1 \(0.003\,{\rm{ppb}}\)
2 \(25\,{\rm{ppm}}\)
3 \(0.04\,{\rm{ppm}}\)
4 \(0.04\,{\rm{ppb}}\)
Explanation:
\({\rm{DDT}}\) in zooplanktons is in \({\rm{0}}{\rm{.04}}\,{\rm{ppm}}\) concentration
BIOXII16: ENVIRONMENTAL ISSUES
345311
In the area where DDT has been used extensively the population of birds declined significantly because
1 Earth worms in the area are eradicated
2 Cobras were feeding exclusively on birds
3 Many of the birds eggs laid did not hatch
4 Birds stopped laying eggs
Explanation:
Birds are secondary or tertiary consumer. The concentration of \({\rm{DDT}}\) is increased in them. \({\rm{DDT}}\) is biodegradable and it leads to decline in the population in birds.
345306
Which of the following options is/are incorrect about algal bloom?
1 Formed by blue-green algae and other planktonic algae
2 Causes fish mortality
3 Causes depletion of \(\mathrm{O}_{2}\) in water
4 Biomagnification with DDT causes it
Explanation:
Biomagnification with DDT causes it is incorrect.
BIOXII16: ENVIRONMENTAL ISSUES
345307
Assertion : There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Reason : Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Domestic sewage is rich in biodegradable organic matter and the decomposition of this organic matter by microorganisms requires oxygen. Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. If sewage quantity is large, the whole of dissolved oxygen may be consumed leaving nothing for respiration for fish and other clean water organisms. They, therefore, get killed. However, as sew age is decomposed, there is a gradual rise in dissolved oxygen downstream. Fish and other clean water organisms reappear indicating the recovery of river from sewage discharge.
BIOXII16: ENVIRONMENTAL ISSUES
345308
DDT in zooplanktons is in ____ concentration
1 \(0.003\,{\rm{ppb}}\)
2 \(25\,{\rm{ppm}}\)
3 \(0.04\,{\rm{ppm}}\)
4 \(0.04\,{\rm{ppb}}\)
Explanation:
\({\rm{DDT}}\) in zooplanktons is in \({\rm{0}}{\rm{.04}}\,{\rm{ppm}}\) concentration
BIOXII16: ENVIRONMENTAL ISSUES
345311
In the area where DDT has been used extensively the population of birds declined significantly because
1 Earth worms in the area are eradicated
2 Cobras were feeding exclusively on birds
3 Many of the birds eggs laid did not hatch
4 Birds stopped laying eggs
Explanation:
Birds are secondary or tertiary consumer. The concentration of \({\rm{DDT}}\) is increased in them. \({\rm{DDT}}\) is biodegradable and it leads to decline in the population in birds.
345306
Which of the following options is/are incorrect about algal bloom?
1 Formed by blue-green algae and other planktonic algae
2 Causes fish mortality
3 Causes depletion of \(\mathrm{O}_{2}\) in water
4 Biomagnification with DDT causes it
Explanation:
Biomagnification with DDT causes it is incorrect.
BIOXII16: ENVIRONMENTAL ISSUES
345307
Assertion : There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Reason : Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Domestic sewage is rich in biodegradable organic matter and the decomposition of this organic matter by microorganisms requires oxygen. Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. If sewage quantity is large, the whole of dissolved oxygen may be consumed leaving nothing for respiration for fish and other clean water organisms. They, therefore, get killed. However, as sew age is decomposed, there is a gradual rise in dissolved oxygen downstream. Fish and other clean water organisms reappear indicating the recovery of river from sewage discharge.
BIOXII16: ENVIRONMENTAL ISSUES
345308
DDT in zooplanktons is in ____ concentration
1 \(0.003\,{\rm{ppb}}\)
2 \(25\,{\rm{ppm}}\)
3 \(0.04\,{\rm{ppm}}\)
4 \(0.04\,{\rm{ppb}}\)
Explanation:
\({\rm{DDT}}\) in zooplanktons is in \({\rm{0}}{\rm{.04}}\,{\rm{ppm}}\) concentration
BIOXII16: ENVIRONMENTAL ISSUES
345311
In the area where DDT has been used extensively the population of birds declined significantly because
1 Earth worms in the area are eradicated
2 Cobras were feeding exclusively on birds
3 Many of the birds eggs laid did not hatch
4 Birds stopped laying eggs
Explanation:
Birds are secondary or tertiary consumer. The concentration of \({\rm{DDT}}\) is increased in them. \({\rm{DDT}}\) is biodegradable and it leads to decline in the population in birds.
345306
Which of the following options is/are incorrect about algal bloom?
1 Formed by blue-green algae and other planktonic algae
2 Causes fish mortality
3 Causes depletion of \(\mathrm{O}_{2}\) in water
4 Biomagnification with DDT causes it
Explanation:
Biomagnification with DDT causes it is incorrect.
BIOXII16: ENVIRONMENTAL ISSUES
345307
Assertion : There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Reason : Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Domestic sewage is rich in biodegradable organic matter and the decomposition of this organic matter by microorganisms requires oxygen. Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. If sewage quantity is large, the whole of dissolved oxygen may be consumed leaving nothing for respiration for fish and other clean water organisms. They, therefore, get killed. However, as sew age is decomposed, there is a gradual rise in dissolved oxygen downstream. Fish and other clean water organisms reappear indicating the recovery of river from sewage discharge.
BIOXII16: ENVIRONMENTAL ISSUES
345308
DDT in zooplanktons is in ____ concentration
1 \(0.003\,{\rm{ppb}}\)
2 \(25\,{\rm{ppm}}\)
3 \(0.04\,{\rm{ppm}}\)
4 \(0.04\,{\rm{ppb}}\)
Explanation:
\({\rm{DDT}}\) in zooplanktons is in \({\rm{0}}{\rm{.04}}\,{\rm{ppm}}\) concentration
BIOXII16: ENVIRONMENTAL ISSUES
345311
In the area where DDT has been used extensively the population of birds declined significantly because
1 Earth worms in the area are eradicated
2 Cobras were feeding exclusively on birds
3 Many of the birds eggs laid did not hatch
4 Birds stopped laying eggs
Explanation:
Birds are secondary or tertiary consumer. The concentration of \({\rm{DDT}}\) is increased in them. \({\rm{DDT}}\) is biodegradable and it leads to decline in the population in birds.
