During transcription,the holoenzyme $RNA$ polymerase binds to a $DNA$ sequence,and the $DNA$ assumes a saddle-like structure at that point. What is that sequence called?

One die and a coin (both unbiased) are tossed simultaneously. The probability of getting $5$ on the top of the die and tail on the coin is

Justify that the following reactions are redox reactions:
$a$. $CuO_{(s)} + H_{2(g)} \rightarrow Cu_{(s)} + H_2O_{(g)}$
$b$. $Fe_2O_{3(s)} + 3CO_{(g)} \rightarrow 2Fe_{(s)} + 3CO_{2(g)}$
$c$. $4BCl_{3(g)} + 3LiAlH_{4(s)} \rightarrow 2B_2H_{6(g)} + 3LiCl_{(s)} + 3AlCl_{3(s)}$
$d$. $2K_{(s)} + F_{2(g)} \rightarrow 2K^{+}F^{-}_{(s)}$
$e$. $4NH_{3(g)} + 5O_{2(g)} \rightarrow 4NO_{(g)} + 6H_2O_{(g)}$

$A$ radioactive nucleus $A$ with a half-life $T$ decays into a nucleus $B$. At $t = 0$,there is no nucleus $B$. At some time $t$,the ratio of the number of $B$ nuclei to that of $A$ nuclei is $0.3$. Then,$t$ is given by:

Olfactoreceptors are:

The sum total of all the chemical reactions occurring in our body is known as