The energy-releasing metabolic process in which substrate is oxidized without an external electron acceptor is called:

The figure shows a system of logic gates. From the study of the truth table,it can be found that to produce a high output $(1)$ at $R$,we must have

If the number of $5$-element subsets of the set $A = \{a_1, a_2, \ldots, a_{20}\}$ of $20$ distinct elements is $k$ times the number of $5$-element subsets containing $a_4$,then $k$ is

What is the process of breeding crops to increase their levels of minerals,vitamins,and proteins called?

If two angles of $\triangle ABC$ are $45^{\circ}$ and $60^{\circ}$,then the ratio of the smallest side to the greatest side is:

$A$ wire fixed at the upper end stretches by length $l$ by applying a force $F$. The work done in stretching is