Naman got into a quarrel with some farmers who were spraying DDT in their field. Many people
gathered at the spot to see and enjoy the incident. The angry mob demanded that Naman should
not interfere with the farmers' job. Naman tried to explain his point and finally succeeded. The
farmers gave up spraying DDT.
i. What did Naman explain to the farmers?
ii. What is biomagnification? Explain with an example.
iii. What values did Naman promote?
i. How do food chains get shortened? How does the shortening of food chain affect the
biosphere?
ii. How will you justify that vegetarian food habits give us more calories?
Answers
Explanation:
1. Naman must explained that by spraying DDT it accomodate poison in crops which leads to case in human beings like damage liver, nervous system and reproductive system .
DDT can also cause various types of cancers , including liver cancer.
2.The increase in the concentration of harmful chemical substances like pesticides in the body of living organisms at each tropic level of a food chain is called biomagnification.
For Example : considered the following food chain
Grass Grasshopper Frog snake peacock
In this food chain , peacock at the highest trophic level , so it will have the maximum concentration of harmful chemicals in its body .
3. The values promoted by Naman are
i. Awareness of DDT that it is harmful to human beings and other animals.
ii. concern for the farmer that DDT may not enter his respiratory system and damage it .
iii. concern for the environment because DDT is non - biodegradable pesticides and persists in the soil and water bodies for a very long time .
1.This shortening of the food chain results in the imbalances within the ecosystem and biosphere. The organisms of successive trophic levels decrease in number due to the elimination of the lower trophic level, this results in the imbalance within the ecosystem and biosphere.
2.Generally organisms at the lowest trophic level are always greater in number . As we move to thr higher trophic levels, the number and complexity of organisms increased. Producers support larger number of organisms. Therefore, vegetarians food habits can sustain a large number of people.
i.)Naman explain to the farmers that by spraying DDT it effects Human health at low environmental doses. Following exposure to high doses, human symptoms can include vomiting, tremors or shakiness, and seizures. Laboratory animal studies showed effects on the liver and reproduction. DDT is considered a possible human carcinogen.
ii.)Biomagnification is the accumulation of a chemical by an organism from water and food exposure that results in a concentration that is greater than would have resulted from water exposure only and thus greater than expected from equilibrium.
Example:-It is the presence of mercury within predatory fish. This level is so high that consuming these can cause cancer.
iii.) Values did Naman promote for farmers awareness of DDT that is harmful for farmer and their children.
a.)Vegetarian food chain gives ten times more energy than the non-vegetarian food chain. of organisms belonging to one or more trophic levels in a food chain. Thus, the food chain gets shortened, e.g. hunting tigers for their skin, etc. It causes imbalance in the functioning of the ecosystem and biosphere.
b.)Animals (herbivores) contain 10% of food energy as compared to plants (producers). For example; the same amount of producer which supplies say 1000 J of food energy to a vegetarian will provide only 100 J of food energy to a non-vegetarian. Hence, a vegetarian will be at an advantageous position.
Explanation:-
- Dichlorodiphenyltrichloroethane (DDT) is an insecticide used in agriculture.
- Some countries outside the United States still use DDT to control of mosquitoes that spread malaria.
- DDT it effects Human health at low environmental doses. Following exposure to high doses, human symptoms can include vomiting, tremors or shakiness, and seizures.
- Laboratory animal studies showed effects on the liver and reproduction.