Genes that are involved in turning on or off the transcription of a set of structural genes are called

Match the following:

List-$I$	List-$II$
$(A)$ Electron deficient hydride	$(I)$ $CH_4$
$(B)$ Electron precise hydride	$(II)$ $B_2H_6$
$(C)$ Electron rich hydride	$(III)$ $CaH_2$
$(D)$ Saline hydride	$(IV)$ $NiH_{0.6}$
	$(V)$ $PH_3$

What is the similarity between $DNA$ and $RNA$?

"Exobiology" refers to the study of

$A$ wire has a resistance of $12 \, \Omega$. It is bent in the form of an equilateral triangle. The effective resistance between any two corners of the triangle is:

$A$ student is to answer $10$ out of $13$ questions in an examination such that he must choose at least $4$ from the first $5$ questions. The number of choices available to him is