The anatomy of springwood shows some peculiar features. Identify the correct set of statements about springwood.
a. | It is also called as the early wood. |
b. | In spring season cambium produces xylem elements with narrow vessels. |
c. | It is lighter in colour. |
d. | The springwood along with autumn wood shows alternate concentric rings forming annual rings. |
e. | It has lower density. |
Choose the correct answer from the options given below:
1. (c), (d) and (e) Only
2. (a), (b), (d) and (e) Only
3. (a), (c), (d) and (e)Only
4. (a), (b) and (d) Only
Axillary buds are derived from the activity of :
1. Lateral meristem
2. Secondary meristem
3. Apical meristem
4. Intercalary meristem
In old trees the greater part of secondary xylem is dark brown and resistant to insect attack due to :
a. | secretion of secondary metabolites and their deposition in the lumen of vessels. |
b. | deposition of organic compounds like tannins and resins in the central layers of stem. |
c. | deposition of suberin and aromatic substances in the outer layer of stem. |
d. | deposition of tannins, gum, resin and aromatic substances in the peripheral layers of stem. |
e. | presence of parenchyma cells, functionally active xylem elements and essential oils. |
Choose the correct answer from the options given below
1. (b) and (d) Only
2. (a) and (b) Only
3. (c) and (d) Only
4. (d) and (e) Only
(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. |
(i) | Meristematic tissue is made of immature cells |
(ii) | A common structural feature of vessel elements and sieve tube is an enucleate condition |
(iii) | Root cap in monocots is formed by calyptrogen |
(iv) | All xylem elements are dead at maturity |
(v) | Collenchyma is a dead mechanical tissue |