Give reasons for the following. NCERT Exemplar . (a) Fresh milk is boiled before consumption while processed milk stored in packets can be consumed without boiling. (b) Raw vegetables and fruits are kept in refrigerators whereas jams and pickles can be kept outside. (c) Farmers prefer to grow beans and peas in nitrogen-deficient soils. (d) Mosquitoes can be controlled by preventing stagnation of water though they do not live in water. Why?

Give reasons for the following. NCERT Exemplar . (a) Fresh milk is b

1.	Give reasons for the following. NCERT Exemplar . (a) Fresh milk is boiled before consumption while processed milk stored in packets can be consumed without boiling. (b) Raw vegetables and fruits are kept in refrigerators whereas jams and pickles can be kept outside. (c) Farmers prefer to grow beans and peas in nitrogen-deficient soils. (d) Mosquitoes can be controlled by preventing stagnation of water though they do not live in water. Why?
Answer» a)Fresh milk is boiled before consumption to KILL the microorganisms in it. But PACKED milk is pasteurised and does not contain any microorganisms. It can thus be consumed without boiling.b)It is because pickles and jams contains some preservatives such as sugar, salt and other ingredients in them. Though, pickles and jams do not easily get spoil by bacteria, air or other factors when you are KEPT them outside.c)Beans and pea are the examples of leguminous plants. These plants contain Rhizobium bacteria in their root nodules which help in fixing atmospheric nitrogen. This results in the enrichment of soil with nitrogen and increases its FERTILITY. Therefore farmers prefer to grow pea and beans in nitrogen deficient soil.d)Mosquito can be controlled by preventing stagnation of water though they do not live in water. ... This is because stagnant water provides breeding ground to the MOSQUITOES. So, by preventing their breeding (mating), mosquitoes can be controlled.