In the dicot root, the vascular cambium:-
1. is absent
2. is completely secondary in origin
3. does not form a continuous ring
4. originates from the tissue just above the phloem bundles
Lignin is a component of the secondary walls of:-
A plant requires potassium for:
(1) Holding its cells together
(2) Synthesizing chlorophyll
(3) DNA replication
(4) Opening and closing its stomata
The shoot apical meristem in a dicot embryo is located:
(1) Between the two cotyledons
(2) Within the root apex
(3) Around the suspensor
(4) In the endosperm
Summer wood is:
(1) the same as heartwood.
(2) found to the outside of each annular ring of xylem.
(3) found to the inside of each annular ring of xylem.
(4) formed throughout the growing season.
Read the different components from I to IV in the list given below and tell the correct order of the components with reference to their arrangement from outer side to inner side in a woody dicot stem
I. Secondary cortex
III. Secondary phloem
The correct order is
(1) III, IV, II, I
(2) I, II, IV, III
(3) IV, I, III, II
(4) IV, III, I, II
Identify the wrong statement in context of heartwood.
(a) Organic compounds are deposited in it
(b) it is highly durable
(c) It conducts water and minerals efficiently
(d) It comprises dead elements with highly lignified walls
Which of the following facilitates opening of stomatal aperture :-
(a) Contraction of outer wall of guard cells
(b) Decrease in turgidity of guard cells
(c) Radial orientation of cellulose microfibrils in the cell wall of guard cells
(d) Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells
Which of the following is made up of dead cells?
(a) Xylem parenchyma
The vascular cambium normal gives rise to.
(a) phelloderm (b) primary phloem
(c) secondary xylem (d) periderm