True or False
Reduction of nitrates to nitrites is carried by an enzyme called nitrate reductase, which I flavoprotein and contains iron for its activity.

Two questions consist of two statements each, printed as Assertion and Reason. While answering these questions, you required to choose any one of the following four responses. If both Assertion and Reason are true and Reason is a correct explanation of Association. If both Association and Reason are true and Reasons is not a correct explanation of Assertion. If Assertion is true but Reason is false. If both Assertions and Reason are false. Assertion: DNA segments can be excised by 'molecular scissors or chemical scalpels' what biotechnologists call restriction enzymes. Reason: Restriction enzymes are synthesized by microbes as a defence mechanism are specific endonucleases which are cleave double stranded DNA.

Solid calcium oxide reacts vigourously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is true about slaking of lime and the solution formed? (i) It is an endothermic reaction (ii) It is an exothermic rection (iii)The pH of the resulting solution will be more than seven (iv)The pH of the resulting solution will be less than seven

State which of the following are True and Which are False: The sides of a polygon are called its diagonals.

In the following statements ,tick 'T' against those which are true and 'F' against those which are false. The number opf oscillations per second of a viberating object is called its time period. (T/F)

These questions consist of two statements each,printed as Assertion and Reason.While asnwering these questions you are required to chose any one of the following four responses. If both Assertion and Reason are true and Reason in correct explanation of Assertion. If both assertion and Reason are true but reason is not correct explanation of Assertion. If Assertion is true but Reason is false. If both Assertion and Reason are false. Assertion:Proteins are commonly called body building biomolecules. Reason:Proteins act as enzymes which regulate the metabolism.