$A$ : Bast fibres are collenchymatous fibres.
$R$ : Fibres are absent in secondary phloem.

Presence of vessels in the wood is:

Which of the following shows physiological xerophytic characters?

In which plant group is the structure shown below found?

Read the following four statements $(A-D)$:
$(A)$ Both photophosphorylation and oxidative phosphorylation involve uphill transport of protons across the membrane.
$(B)$ In dicot stems,a new cambium originates from cells of pericycle at the time of secondary growth.
$(C)$ Stamens in flowers of Gloriosa and Petunia are polyandrous.
$(D)$ Symbiotic nitrogen fixers occur in free-living state also in soil.
How many of the above statements are right?

How is the study of plant anatomy useful to us?