Statement I: | Endarch and exarch are the terms often used for describing the position of secondary xylem in the plant body. |
Statement II: | Exarch condition is the most common feature of the root system. |
A: | Lenticels are the lens-shaped openings permitting the exchange of gases. |
B: | Bark formed early in the season is called hard bark. |
C: | Bark is a technical term that refers to all tissues exterior to vascular cambium. |
D: | Bark refers to periderm and secondary phloem. |
E: | Phellogen is single- layered in thickness. |
1. | B and C only | 2. | B, C and E only |
3. | A and D only | 4. | A, B and D only |
1. | Monocot root | 2. | Dicot root |
3. | Dicot stem | 4. | Monocot stem |
1. | (A), (B), (D), (C) | 2. | (B), (A), (C), (D) |
3. | (A), (B), (C), (D) | 4. | (B), (A), (D), (C) |
1. | Parenchyma | 2. | Collenchyma |
3. | Sclerenchyma | 4. | Sclereid |
1. | Epiblema | 2. | Cortex |
3. | Endodermis | 4. | Pericycle |
Which of the following is not a character of collenchyma tissue?
1. | They provide mechanical support to the growing part of the plant |
2. | They occur in layers below epidermis in dicotyledonous plants |
3. | They consist of cells with thick corners due to cellulose deposition |
4. | They are usually dead and without protoplasts |
Select the correct statements related to the activity of cork cambium:
1. | The outer cells differentiate into phelloderm. |
2. | The cork differentiated from cork cambium, is impervious to water due to deposition of tannins and resins. |
3. | Cuts the cells only on the outer side. |
4. | Cuts the cells on inner as well as outer side. |
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
a. | In roots, xylem and phloem in a vascular bundle are arranged in an alternate manner along the different radii. |
b. | Conjoint closed vascular bundles do not possess cambium. |
c. | In open vascular bundles, cambium is present in between xylem and phloem. |
d. | The vascular bundles of dicotyledonous stem possess endarch protoxylem. |
e. | In monocotyledonous root, usually there are more than six xylem bundles present. |