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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.
In the light of the above statements, choose the correct answer from the options given below:
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:
Given below are two statements: One is labelled as Assertion A and the other islabeled as Reason R:
Assertion A: A flower is defined as modified shoot wherein the shoot apical meristem changes to floral meristem.
Reason R: Internode of the shoot gets condensed to produce different floral appendages laterally at successive nodes instead of leaves.
In the light of the above statements, choose the correct answer from the options given below:
Identify the correct statements:
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.
Choose the correct answer from the options given below:
Read the following statements about the vascular bundles :
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.
Choose the correct answer from the options given below :
In old trees the greater part of secondary xylem is dark brown and resistant to insect attack due to:
A. secretion of secondary metabolities 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:
Match List-I with List-II.
List-I | List-II |
---|---|
(A)Lenticels | (I)Phellogen |
(B)Cork cambium | (II)Suberin deposition |
(C)Secondary cortex | (III)Exchange of gases |
(D)Cork | (IV)Phelloderm |
Match List-I with List-II.
List-I | List-II |
---|---|
(A)Cells with active cell division capacity | (I)Vascular tissues |
(B)Tissue having all cells similar in structure and function | (II)Meristematic tissue |
(C)Tissue having different types of cells | (III)Sclereids |
(D)Dead cells with highly thickened walls and narrow lumen | (IV)Simple Tissue |
Select the correct pair.
Large colorless empty cells in the epidermis of grass leaves | - Subsidiary cells |
In dicot leaves, vascular bundles are surrounded by large thick-walled cells | - Conjunctive tissue |
Cells of medullary rays that form part of cambial ring | - Interfascicular cambium |
Loose parenchyma cells rupturing the epidermis and forming a lensshaped opening in bark | - Spongy parenchyma |
Cells of medullary rays that form part of cambial ring | Interfascicular cambium |
Which of the following statements about cork cambium is incorrect?
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