- 1(current)
Q. No.How many of the following statements are true for heartwood?
I. It provides mechanical support to the stem
II. It does not conduct water
III. It is hard, durable, and resistant to the attacks of microbes
IV. It is the innermost layer of the wood
V. It comprises dead elements with highly lignified walls
VI. More the heartwood is present, the better is the quality of the wood
1. Four
2. Five
3. Six
4. Three
A: The secondary xylem is derived from procambium during secondary growth.
R: The amount of secondary xylem is almost equal to the amount of secondary phloem.
1. If both Assertion & Reason are true and the reason is the correct explanation of the assertion.
2. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion.
3. If the Assertion is a true statement but the reason is false.
4. If both Assertion and Reason are false statements.
Assertion (A): Amount of secondary xylem produced is more than the secondary phloem in the dicot stem.
Reason (R): Cambium is generally more active on the inner side than on the outer.
1. If both Assertion & Reason are true and the reason is the correct explanation of the assertion.
2. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion.
3. If Assertion is a true statement but the reason is false.
4. If both Assertion and Reason are false statements.
| (i) | The cambium is generally more active on the inner side than on the outer side. |
| (ii) | The cells which are cut off towards pith by cambium mature into secondary phloem and cells cut off towards periphery mature into secondary xylem. |
| (iii) | The amount of secondary xylem produced is more than secondary phloem. |
| (iv) | The primary and secondary phloems get gradually crushed due to the continued formation and accumulation of secondary xylem. |
| (v) | The primary xylem also gets crushed and rarely remains intact. |
How many of the above statements are correct?
1. Three
2. Two
3. Four
4. One
(i) It does not help in water conduction
(ii) It is light coloured
(iii) It is also called alburnum
(iv) Its tracheary elements are filled with tannins, resins, oils, gums aromatic compounds, and essential oils
(v) It is hard and durable
1. (ii), (iii)
2. (i), (ii), (iii)
3. (iv), (v)
4. (iii), (iv), (v)
- 1(current)
Q. No.
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