The mineral constituent of the cell wall is

In a plant cell,the deposition of which substance on the primary cell wall leads to the formation of the secondary cell wall?

The internal layer joining the primary walls of the two adjacent cells is known as

The middle lamella between plant cells is composed of which substance?

Assertion $A$: The middle lamella is present between the primary walls of two adjacent plant cells.
Reason $R$: Two adjacent cells maintain cytoplasmic contact through plasmodesmata.
Which option is correct for Assertion $A$ and Reason $R$?

Yeast cell wall is rich in