$A$ fibre derived from a tracheid is

Which of the following tissues is found in mature plant parts?

In the autumn season, the callus pads appear on

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 $B$.

Companion cells are found in the phloem of

Callus is made up of