Plant growth in length is increased by

The following figure shows a longitudinal section of a shoot apex. Select the correct option for $P$ and $Q$.

Option	$P$	$Q$
$A$	Meristematic tissue	Plumule
$B$	Plumule	Differentiated vascular tissue
$C$	Plumule	Axillary bud
$D$	Meristematic region	Axillary bud

Which meristematic tissue is responsible for increasing the girth of the plant?

$A$: Intercalary meristems are commonly located at the base of leaves,above the nodes,or below the nodes.
$R$: Vacuoles are large-sized in the cells of intercalary meristem.

The $Korper-Kappe$ theory was proposed by:

Write a note on Meristematic tissue.