41.A violin has four strings but only two of them are used, the other two strings exist to produce

42.Which of the following acids is most important in building tissue proteins ?

43.Given below are two statements, labelled as Assertion (A) and Reason (R). In the context of the two statements, which of the following is correct ?Assertion (A) : Organo chlorine pesticides like DDT, although highly effective in controlling the insect pests, have been banned in many western countries.Reason (R) : DDT has a tendency to remain stable in the environment for long periods.

44.Which of the following is the name of the smallest part of the matter discovered recently by the scientists ?

45.Given below are two statements, labelled as Assertion (A) and Reason (R). In the context of the two statements, which of the following is correct ?Assertion (A) : Vitamins are nutrients required in small quantities for good health.Reason (R) : Vitamins help to maintain a healthy body by killing harmful bacteria.