In $........$ and $........$ organisms or the parent cell divides into two to give rise to new individuals.

What is the cause of embryo formation from pollen grains in tissue culture medium?

If $\alpha, \beta, \gamma$ are the roots of the equation $x^3+a x^2+b x+c=0$,then $\alpha^{-1}+\beta^{-1}+\gamma^{-1}$ is equal to

$A$ particle $A$ has charge $+q$ and particle $B$ has charge $+4q$,with each of them having the same mass $m$. When allowed to fall from rest through the same electrical potential difference,the ratio of their speeds $V_A : V_B$ will be:

Which country produces the maximum amount of greenhouse gases?

During which of the following reactions will a gaseous product $NOT$ be produced?