$A$ : Oldest layer of sapwood lies just outside vascular cambium.
$R$ : Sapwood contains actively conducting vessels and occupies central part of stem.
Assertion and Reason both are correct and also correct explanation.
Assertion and Reason both are correct but not explanation of assertion.
Assertion is correct, but Reason is incorrect.
Both Assertion and Reason are incorrect.
In a plant organ which is covered by periderm and in which the stomata are absent, some gaseous exchange still takes place through
What constitutes the cambial ring?