Observe figure and answer the following questions.
i. What ecological term is used to describe the DDT accumulation at different trophic levels?
ii. List any one effect of DDT accumulation on birds.
iii. Will DDT accumulation lead to eutrophication?
iv. Does it affect the BOD?
v. Name disease caused by accumulation of any heavy metal.
i. What ecological term is used to describe the DDT accumulation at different trophic levels?
ii. List any one effect of DDT accumulation on birds.
iii. Will DDT accumulation lead to eutrophication?
iv. Does it affect the BOD?
v. Name disease caused by accumulation of any heavy metal.
Solution :i:
Introduction:
Biomagnification is the increase in accumulation of toxic substances within organisms at each successive level of the food chain. Biomagnification is caused by insecticides like Dichloro diphenyl trichloroethane (DDT) and heavy metals like mercury which cannot be metabolised and excreted, hence, accumulate in the tissues.
Final answer:
Biomagnification
Solution :ii:
Effect of DDT on bird population:
DDT was used as an insecticide in agriculture and was released into the water bodies. This caused its accumulation in fishes and the birds feeding on these fishes. This accumulation of DDT caused infertility, thinning of eggshells, and killing of the embryo resulting in decline of bird population.
Final answer:
Thinning of egg shell
Solution: iii:
Introduction to eutrophication:
Eutrophication is the enrichment of water bodies with elements like nitrogen and phosphorus. When excess fertilisers or pesticides used in agricultural fields are washed off into water bodies, the natural ageing of the water body gets accelerated. This is called accelerated eutrophication. The excess nutrients present cause excessive growth of algae.
DDT and eutrophication:
DDT has been used in agricultural fields as pesticides. Hence, it does not cause eutrophication.
Final answer:
No
Solution: iv:
Definition of BOD:
Biochemical oxygen demand (BOD) is the amount of dissolved oxygen required by aerobic bacteria to oxidise the organic matter present in the sample water at a specific period of time and temperature.
Significance :
If the BOD levels in a water sample is more than the limit, the organic matter present is more, indicating more pollution. If BOD levels are less, the pollution levels are less.
Effect of DDT on BOD:
Presence of DDT increases the organic matter present in the water sample, increasing the BOD.
Final answer:
It increases BOD
Solution :v:
Disease due to heavy metal poisoning:
Minamata disease is a neurological disorder caused by the accumulation of mercury (heavy metal) in the brain of humans due to consumption of seafood contaminated with the toxic element.
Final answer:
Minamata disease
Introduction:
Biomagnification is the increase in accumulation of toxic substances within organisms at each successive level of the food chain. Biomagnification is caused by insecticides like Dichloro diphenyl trichloroethane (DDT) and heavy metals like mercury which cannot be metabolised and excreted, hence, accumulate in the tissues.
Final answer:
Biomagnification
Solution :ii:
Effect of DDT on bird population:
DDT was used as an insecticide in agriculture and was released into the water bodies. This caused its accumulation in fishes and the birds feeding on these fishes. This accumulation of DDT caused infertility, thinning of eggshells, and killing of the embryo resulting in decline of bird population.
Final answer:
Thinning of egg shell
Solution: iii:
Introduction to eutrophication:
Eutrophication is the enrichment of water bodies with elements like nitrogen and phosphorus. When excess fertilisers or pesticides used in agricultural fields are washed off into water bodies, the natural ageing of the water body gets accelerated. This is called accelerated eutrophication. The excess nutrients present cause excessive growth of algae.
DDT and eutrophication:
DDT has been used in agricultural fields as pesticides. Hence, it does not cause eutrophication.
Final answer:
No
Solution: iv:
Definition of BOD:
Biochemical oxygen demand (BOD) is the amount of dissolved oxygen required by aerobic bacteria to oxidise the organic matter present in the sample water at a specific period of time and temperature.
Significance :
If the BOD levels in a water sample is more than the limit, the organic matter present is more, indicating more pollution. If BOD levels are less, the pollution levels are less.
Effect of DDT on BOD:
Presence of DDT increases the organic matter present in the water sample, increasing the BOD.
Final answer:
It increases BOD
Solution :v:
Disease due to heavy metal poisoning:
Minamata disease is a neurological disorder caused by the accumulation of mercury (heavy metal) in the brain of humans due to consumption of seafood contaminated with the toxic element.
Final answer:
Minamata disease
