Who first suggested the idea of circular flow of genetic information?

The ratio of rates of diffusion of gases $X$ and $Y$ is $1:5$ and that of $Y$ and $Z$ is $1:6$. The ratio of rates of diffusion of $Z$ and $X$ is

In which of the following reactions,$MgO$ is not formed?

If $(1, a)$ and $(b, 2)$ are conjugate points with respect to the circle $x^2+y^2=25$,then $4a+2b$ is equal to

If $l, m, n$ are in arithmetic progression,then the straight line $lx + my + n = 0$ will always pass through the point:

$A$ manometer connected to a closed tap reads $4.5 \times 10^5 \, Pa$. When the tap is opened,the reading of the manometer falls to $4 \times 10^5 \, Pa$. The velocity of the flow of water is ........ $m/s$.