Secondary xylem and phloem in dicot stem are produced by
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 II. Wood III. Secondary phloem IV. Phellem The correct order is
III,IV,II,I
I,II,IV,III
IV,I,III,II
IV,III,I,II
Tracheids differ from the tracheary elements in :
Having casparian strips
Being imperforate
Lacking nucleus
Being lignified
Gymnosperms are also called soft wood spermatophytes because they lack
Cambium
Phloem fibres
Thick-walled tracheids
Xylem fibres
all tissues except epidermis and vascular bundles
epidermis and cortex
all tissues internal to endodermis
all tissues external to endodermis
phellogen
periderm
phellem
phelloderm
The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is
maturing
elongating
widening
differentiating
shoot apical meristem
position of axillary buds
size of leaf lamina at the node below each internode
intercalary meristem
Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following :
Tyloses in vessels
closure of stomata
Flaccidity of bulliform cells
Shrinkage of air spaces in spongy mesophyll
Phloem in gymnosperms lacks:
Both sieve tubes and companion cells
Albuminous cells and sieve cells
Sieve tubes only
Companion cells only
Which of the statements given below is not true about the formation of Annual Rings in trees?
Annual rings are not prominent in trees of temperate regions.
Annual rings are a combination of spring wood and autumn wood produced in a year.
Differential activity of cambium causes light and dark bands of tissue - early and late wood respectively.
Activity of cambium depends upon variation in climate.
In the dicot root the vascular cambium originates from :
Tissue located below the phloem bundles and a portion of pericycle tissue above protoxylem.
Cortical region
Parenchyma between endodermis and pericycle
Intrafascicular and interfascicular tissue in a ring
Regeneration of damaged growing grass following grazing is largely due to :
Lateral meristem
Apical meristem
Intercalary meristem
Secondary meristem
Identify the incorrect statement.
Sapwood is involved in conduction of water and minerals from root to leafs.
Sapwood is the innermost secondary xylem and is lighter in colour
Due to deposition of tannins, resins, oils etc., heart wood is dark in colour.
Heart wood does not conduct water but gives mechanical support.
The transverse section of a plant shows following anatomical features :
a. Large number of scattered vascular bundles surrounded by bundle sheath.
b. Large conspicuous parenchymatous ground tissue.
c. Vascular bundles conjoint and closed.
d. Phloem parenchyma absent.
Identify the category of plant and its part :
Monocotyledonous root
Dicotyledonous stem
Dicotyledonous root
Monocotyledonous stem
Large, empty colorless cells of the adaxial epidermis along the veins of grass leaves are
Lenticels
Guard cells
Bundle sheath cells
Bulliform cells
Which of the following statements about cork cambium is incorrect?
It forms a secondary cortex on its outside
It forms a part of periderm
It is responsible for the formation of lenticels
It is a couple of layers thick
Given below is the diagram of a stomatal apparatus. In which of the following all the four parts labelled as A, B, C and D are correctly identified –
A B C D
Match List I with 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
(d) Dead cells
with highly thickened
walls and narrow lumen
Select the correct answer from the options given below.
(a) (b) (c) (d)
(i) (ii) (iii) (iv)
(iii) (ii) (iv) (i)
(ii) (iv) (i) (iii)
(iv) (iii) (ii) (i)
Match List-I with List-II.
Choose the correct answer from the options given below.
(ii) (iii) (iv) (i)
(iv) (ii) (i) (iii)
(iv) (i) (iii) (ii)
(iii) (i) (iv) (ii)
Select the correct pair.
Cells of medullary rays that form part of a cambial ring - Interfascicular cambium
Loose parenchyma cells rupturing the epidermis and forming a lens-shaped opening in the bark - Spongy parenchyma
Large colorless empty cells in the epidermis of grass leaves - Subsidiary cells
In dicot leaves, vascular bundles are surrounded tissue by large thick-walled cells - Conjunctive tissue
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