State true (T) or false (F) to the given statements and select the correct option.
(a) Annual rings are distinct in plants growing in temperate regions.
(b) Lenticels occur in most woody trees and permit the exchange of gasses.
(c) Due to stelar secondary growth central cylinder of wood surrounded by secondary phloem is formed.
(d) The cells of the endodermis opposite to protoxylem divided to give rise to vascular cambium in dicot roots.
Important Questions on Anatomy of Plants
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: Late wood has fewer xylary elements with narrow vessels.
Reason R: Cambium is less active in winters.
In the light of the above statements, choose the correct answer from the options given below:
The trees growing in temperature regions show clear demarcation between spring wood and autumn wood. This is because
*Note- The incorrect answer was marked. It has been changed.
Which of the following are the part of the Periderm?
I. Duramen
II. Phellogen
III. Phellem
IV. Phelloderm
V. Alburnum
The correct answer is
(i) Secondary cortex
(ii) Wood
(iii) Secondary phloem
(iv) Phellem
Match the following lists
| List I | List II | List III |
| A) Lignified walled dead cells | i) Plants are less active | I) Secondary growth of root |
| B) During unfavourable seasons | ii) Pericycle above protoxylem | II) Medullary ray |
| C) Cambium farming narrow band of parenchyma | iii) Does not conduct water | III) Less number of xylem |
| D) Cambium forms below phloem | iv) Between secondary xylem and phloem | IV) Heart wood |
The correct match is:
Assertion (): The spring wood has a greater number of Xylem vessels with wider lumens.
Reason (): During the spring season plant requires a large amount of water mineral salts.
The dendrochronology is based on
Reason (R): The secondary xylem is produced more than the secondary phloem.
The correct option among the following is:
(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:
Assertion The peripheral region of the secondary xylem is lighter in colour and is known as the sapwood (alburnum).
Reason It is involved in the conduction of water and minerals from root to leaf.
The correct answer is:
