Which one of the following is the first step in taxonomy?

In adiabatic compression,the decrease in volume is associated with

Which is the smallest blood vessel in the body?

Consider the following statements $A$ and $B$ and identify the correct answer:
$A$. When a person walks on a rough surface, the direction of the frictional force exerted by the surface on the person is in the direction of his motion.
$B$. When a cycle is in motion, the force of friction exerted by the ground on the front wheel is in the backward direction.

An electron of mass $m$ when accelerated through a potential difference $V$ has de-Broglie wavelength $\lambda$. The de-Broglie wavelength associated with a proton of mass $M$ accelerated through the same potential difference will be:

The ratio $\frac{K_p}{K_c}$ for the reaction $CO_{(g)} + \frac{1}{2}O_{2(g)} \rightleftharpoons CO_{2(g)}$ is