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Assertion : In woody stems, the amount o...

Assertion : In woody stems, the amount of heartwood continues year after year.
Reason: The cambial activity continues uninterrupted.

A

If both assertion and reason are true reason is the correct explanation of assertion

B

If both assertion and reason are true but reason is not the correct explanation of assertion

C

If assertion is true but reason is false

D

If both assertion and reason are false.

Text Solution

Verified by Experts

The correct Answer is:
A
Both assertion and reason is the correct explanation of assertion .
As a result of continued secondary growth for several years, the older parts of the stem and its old branches have a part of its secondary xylem rendered non-functional secondary xylem is called the heart wood or duramen, the functional outer younger rings of secondary xylem constitute the sap wood or alburnum. With the passage of time and addition of new outer rings of secondary xylem due to chambial activity more rings of the sap wood are changed into heart wood. This leads to the increase in the thickness of heart wood, whearas the sap wood remains of about the same thickness.
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