In the given figure,what do $A$ and $B$ represent respectively?

Which tissue provides mechanical support to the young stem and petiole of leaves?

$NH_3 + O_2 \xrightarrow[\Delta]{Pt} A + H_2O;$
$A + O_2 \to B$
$B + O_2 + H_2O \to C$
$A, B$ and $C$ are:

If the equilibrium constant for the reaction,$H_{2(g)} + I_{2(g)} \rightleftharpoons 2 HI_{(g)}$ is $K$,what is the equilibrium constant of $HI_{(g)} \rightleftharpoons \frac{1}{2} H_{2(g)} + \frac{1}{2} I_{2(g)}$?

The average degree of freedom per molecule of a gas is $6$. The gas performs $25 \ J$ of work while expanding at constant pressure. The heat absorbed by the gas is .... $J$

One of the constituents of the pancreatic juice while poured into the duodenum in humans is