Which of the following logic gates is a universal gate?

$X-$ It is very important for the process of evolution.
$Y-$ Crossing over is the exchange of genetic material between two homologous chromosomes.

The focal distance of a point on the parabola $y^2 = 16x$ whose ordinate is twice the abscissa,is

In tissue culture experiments,leaf mesophyll cells are put in a culture medium to form callus. This phenomenon may be called as:

The correct stability order of the given tautomers is:

Consider the following anions:
$(I)$ $CF_{3}SO_{3}^{-}$
$(II)$ $C_{6}H_{5}SO_{3}^{-}$
$(III)$ $C_{6}H_{5}O^{-}$
$(IV)$ $CH_{3}COO^{-}$
When attached to $sp^{3}$-hybridized carbon,their leaving group ability in nucleophilic substitution reaction decreases in the order: