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(a) Mention any one harmful effect of using plastic bags on the environment. Suggest better alternatives to the usage of plastic bags.
(b) Paddy fields require a large amount of water. The pesticides and chemical fertilizers used are washed down into the soil or waterbodies. How do these chemicals reach our bodies ? What is this phenomenon known as ?
(b) Paddy fields require a large amount of water. The pesticides and chemical fertilizers used are washed down into the soil or waterbodies. How do these chemicals reach our bodies ? What is this phenomenon known as ?
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(a) • Plastics being non - biodegradable persist in environment for a long time. (any other harmful effect) (½ Mark)
• Alternative - Jute or cloth bag (any other suitable alternative) (½ Mark)
(b) • Pesticides and chemical fertilizers are not biodegradable. They accumulate progressively at each trophic level. As human beings occupy the top level in any food chain the maximum concentration of these chemicals get accumulated in our bodies. (1 Mark)
• This Phenomenon is biological magnification. (1 Mark)
• Alternative - Jute or cloth bag (any other suitable alternative) (½ Mark)
(b) • Pesticides and chemical fertilizers are not biodegradable. They accumulate progressively at each trophic level. As human beings occupy the top level in any food chain the maximum concentration of these chemicals get accumulated in our bodies. (1 Mark)
• This Phenomenon is biological magnification. (1 Mark)