A farmer was using pesticides on his farm. He used the produce of his farm as food for rearing fishes, He was told that fishes were not fit for human consumption because large amount of pesticides had accumulated in the tissues of fishes. Explain how did this happen ?

A farmer is fed up of weeds in his Wheat farm. Which of the following chemicals he can use to overcome the problem?

Bharath went to his grandfather’s house in winter this year. As usual he went for fishing. His grandmother told him there will be no fishes in the lake. He noticed that it was more difficult to find fishes in winter. The fishes were deep inside the river. Whereas in summer they were on the surface and hence he was able to catch fishes. (a) Why are fishes on the surface in water than in the depth in summer? Srisha wanted to keep ice creams without melting. So he had to keep it on ice taken in a container. His grandmother advised him to pour salt on the ice. (a) Why? (b) What value can be derived from this?

A farmer is growing a crop regularly in his field. He uses chemical fertilizers, pesticides, organic manure as well as bio-fertilizers. Very close to his field is a factory which emits smoke as a by product. There is also a huge lake in the nearby area. Which of these is a way to prevent accumulation of harmful chemicals in our bodies ?