The family in which many plants are $C_4$ type is:

An archaeologist analyses the wood in a prehistoric structure and finds that the ratio of ${C^{14}}$ (half-life $= 5700 \, years$) to ${C^{12}}$ is only one-fourth of that found in the cells of living plants. The age of the wood is about ........ $years$.

$A$ - Events after the formation of zygote are called post-fertilization events.
$R$ - In viviparous animals,a young one develops outside the mother's body.

The temperature at which a real gas obeys ideal gas laws over an appreciable range of pressure is called:

The histogens are classified on the basis of

In $chloroethane$,the carbon bearing halogen is bonded to $...$ hydrogen $(s)$. It is called $......$ alkyl halide.