Question

Which of the following is not correct?
A. Early wood is characterised by a large number of xylary elements
B. Late wood is characteristics by a large number of xylary elements
C. Early wood is characterised by vessels with wider cavities
D. Late wood is characterised by vessels with narrower cavities

Answer 1

Hint: Early wood is produced earlier in the growing season when there is rapid growth whereas late wood is produced later when there is no rapid growth.

Complete answer:
First of all, you should know what early wood and late wood are. Early wood is also known as spring wood. It is a wood which is seen in the growth ring of the tree and it is produced earlier in the growing season when the growth is rapid. Early wood is not that dense because their walls are thinner and the cells are larger. In the spring season, there is production of a large number of xylary elements which have vessels with wider cavities as the cambium is very active in this season.

Late wood is also known as autumn wood. It is a wood in a tree's growth ring which is produced later in the growing season when the growth is not rapid. In winter, when the cambium is less active then there is formation of fewer xylary elements that have narrow vessels and this wood is late wood.

> If we look at option A which is early wood is characterised by a larger number of xylary elements. This statement is correct as per the given explanation above.

> Option B is Late wood characterized by a large number of xylary elements. But as per the explanation above, the cambium is less active during winters and it does not produce larger xylary elements. Therefore, this statement is incorrect.

> Option C is Early wood is characterised by vessels with wider cavities, this statement is right as per the given explanation above.

> Options D is Late wood is characterised by vessels with narrower cavities, this statement is also correct as per the given explanation.

Hence, The correct answer is option (B).

Note: Since in the winters, the cambium is less active and hence it is unable to produce larger number of xylary vessels and there is formation of xylary vessels with narrower vessels thus ‘Late wood is characteristics by a large number of xylary elements'.