The simplest and most primitive embryophytes are ......

In which of the following reactions is benzaldehyde formed from benzoyl chloride and hydrogen in the presence of $Pd/BaSO_4$?

Passive absorption of minerals depends on which of the following?

The fossil bone has a ${}^{14}C:{}^{12}C$ ratio,which is $\left( \frac{1}{16} \right)$ of that in a living animal bone. If the half-life of ${}^{14}C$ is $5730 \text{ years}$,then the age of the fossil bone is ......... $\text{years}$.

The atomic numbers of elements $X, Y$ and $Z$ are $19, 21$ and $25$ respectively. The number of electrons present in the $M$-shell of these elements follow the order:

The function $f: R \rightarrow R$ defined by $f(x)=\frac{x}{\sqrt{1+x^2}}$ is ........