What is the plant body of algae called?

Assertion : For a reaction $2NH_{3(g)} \to N_{2(g)} + 3H_{2(g)}$ ; $\Delta H > \Delta E$
Reason : Enthalpy change is always greater than internal energy change.

The first formed primary phloem is referred to as $A$. The later formed primary phloem is referred to as $B$.
Choose the correct combination of $A$ and $B$.

Which ion is essential for muscle contraction?

What is the name of the bond present between the units that form a disaccharide sugar?