DDT that was sprayed in minute amount on food plants was detected in high concentration in man? How did it happen? Explain

A plant organ having high concentration of food , will serve as a

Why do lepidopterans die when they feed on Bt cotton plant? Explain how does it happen.

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 ?

The following is a food chain that ends with human : plants to bee to human (a) Explain how plants provide food for bees. (b) How do bees provide food for humans ? (c) How does this food chain differ from a usual food chain involving human such as : plants to goat to human ? (d) Do you think that the food chain given in this question can really be regarded as a food chain ? Explain your answer.

A plant cell with 0.5% concetration of salt in its cell sap is palced in a solution with 5% concentration of salt answer the following : (i)What will happen to the cell? (ii) How will you describe the concentration of the outside solution? (iii) What changes ar e required to bring back the normalcy of the cell ?

Explain the following observations: (a) Azide ion (N_(3)) react with 2- bromopentane thousand times faster than with neopentyl bromide in a S_(N)2 reaction through former isa secondary halide while latter is primary. (b) What will happen to teh stereochemistry of product of the following reaction: (c) What will happens to the rate if the concentration of alkyl bromide in (b) is doubled? (d) Wha will happen to the rate if the concentration of azide ion in (b) is doubled? (e) How the sign of optical rotation of reactant and product are related in (b) (f) When allowed to stand in dilute H_(2)SO_(4) laevo-rotatory 2-butanol slowly loss optical activity.

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. Consider the following food chain in the same lake. Aquatic plant to Small fish to Big fish to Birds Which of the above organisms is likely to show minimum amount of pesticide concentration in them after considerable time?