Identify the labels $P$ and $Q$ in the given diagram.

Dermatogen,periblem and plerome are

Identify the tissues $P$ and $Q$ based on their functions:
Tissue $P$: Responsible for the increase in length of roots and stems.
Tissue $Q$: Responsible for the increase in girth (thickness) of roots and stems.
Choose the correct option for $P$ and $Q$.

In plants,during the embryonic stage,the meristematic activity is restricted to:

According to the $Apical$ $Cell$ $Theory$, the shoot apex contains a single apical cell with three cutting faces. This theory applies to some higher algae, bryophytes, and pteridophytes, but not to gymnosperms and angiosperms. Who proposed this theory?

The undifferentiated cells are present in