The partial pressure of oxygen in the alveoli of the lungs is

The $pH$ of blood does not appreciably change by a small addition of an acid or a base because blood

Which of the following is not a peroxy acid?

Lactose is composed of .......

Two adjacent sides of a parallelogram $ABCD$ are given by $\overline{AB}=2 \hat{i}+10 \hat{j}+11 \hat{k}$ and $\overline{AD}=-\hat{i}+2 \hat{j}+2 \hat{k}$. The side $AD$ is rotated by an acute angle $\alpha$ in the plane of the parallelogram so that $AD$ becomes $AD^{\prime}$. If $AD^{\prime}$ makes a right angle with side $AB$,then the cosine of the angle $\alpha$ is given by

In a mutational event,when adenine is replaced by guanine,it is the case of