As secondary growth proceeds, in a dicot stem, the thickness of
sapwood increases.
heartwood increase.
both sapwood and heartwood increases.
both sapwood and heartwood remains the same.
Correct Answer :
C. both sapwood and heartwood increases.
In a very old stem, the secondary xylem elements in the inner part turn darker in colour and is called the heartwood or duramen. It is very strong and durable and imparts great amount of mechanical strength to the stem. The sapwood or alburnum is the light coloured peripheral part of the secondary xylem consists of dead tracheids. Vessels and fibres are some living cells. It helps in the conduction of water and solutes.
Related Questions
The given figure shows T.S. of monocot stem. Identify the correct labelling of A to F marked in the given figure.
A Epidermis, B Hypodermis, C Vascular bundles, D Phloem, E Xylem, F Ground tissue
A Cuticle, B Epidermis, C Sclerenchymatous sheath, D Sclerenchymatous hypodermis, E Parenchymatous sheath, F Phloem
A Cuticle, B Epidermis, C Sclerenchymatous hypodermis, D Sclerenchymatous sheath, E Parenchymatous sheath, F Phloem
A Cuticle, B Epidermis, C Sclerenchymatous hypodermis, D Sclerenchymatous sheath, E Parenchymatous sheath, F Protoxylem
The given diagrams show stomatal apparatus in dicots and monocots. Which one is correct option for A, B and C?
A Epidermal cells; B Subsidiary cells; C chloroplast
A Guard cells; B Subsidiary cells; C Stomatal pore
A Guard cells; B Epidermal cells; C Guard cells
A Epidermal cells; B Subsidiary cells; C Guard cells
A plant tissue when stained showed the presence of hemicellulose and pectin in cells wall of its cells. The tissue is called
collenchyma
sclerenchyma
xylem
meristem
Various functions like photosynthesis, storage, excretion performed by _____________.
sclerenchyma
parenchyma
collenchyma
aerenchyma
As secondary growth proceeds, in a dicot stem, the thickness of
sapwood increases.
heartwood increase.
both sapwood and heartwood increases.
both sapwood and heartwood remains the same.
In an experiment, a student cut a transverse section of young stem of a plant which he has taken from his school garden.
After observing it under the microscope how would he ascertain whether it is a monocot stem or a dicot stem?
With the help of bulliform cells.
With the help of casparian strips.
With the help of vascular bundles.
With the help of stomatal apparatus.
Which one of the following option shows the correct labelling of the parts marked as A, B, C and D in the given figure of a typical dicot root?
A Primary phloem, B Vascular cambium, C Secondary phloem, D Primary xylem
A Secondary phloem, B Vascular cambium, C Primary phloem, D Primary xylem
A Primary phloem, B Primary xylem, C Secondary phloem, D Vascular cambium
A Secondary phloem, B Primary xylem, C Primary phloem, D Vascular cambium
Which of the following process helps the trichomes in preventing water loss?
Where companion cells helps in maintaining the pressure gradient in the sieve tubes.
Where plants absorb water through the roots and then give off water vapor through pores in their leaves.
Where activity of cork cambium builds pressure on the remaining layers peripheral to phellogen and ultimately these layers dies and slough off.
None of the above
Which meristem helps in increasing girth?
Lateral meristem
Intercalary meristem
Primary meristem
Apical meristem
Which one of the following statement is incorrect ?
- Epidermal cell has small amount of cytoplasm and a large vacuole.
- Waxy cuticle layer is absent in roots.
- Root hairs are unicellular, while stem hairs / trichomes are multicellular.
- Trichomes may be branched or unbranched, soft or stiff and prevent transpiration.
- Guard cells are dumbell shaped in dicots and beanshaped in monocots (e.g. grass).
Only (i)
Only (iv)
Only (iii)
Only (v)
Sclerenchyma usually___________and_____________ protoplasts.
live, without
dead, with
live, with
dead, without
Tissue(s) present in an annual ring is/are
secondary xylem and phloem.
primary xylem and phloem.
secondary xylem only.
primary phloem and secondary xylem.
T.S. of dicot leaf passing through the midrib is given below. Certain parts have been marked by alphabets (A to H). Choose the option showing their correct labelling.
A Epidermis, B Spongy mesophyll, C Palisade mesophyll, D Stomata, E Guard cells, F Phloem, G Metaxylem, H Protoxylem
A Epidermis, B Palisade mesophyll, C Spongy mesophyll, D Sub-stomatal cavity, E Stoma, F Phloem, G Xylem, H Bundle sheath
A Epidermis, B Palisade mesophyll, C Spongy mesophyll, D Stomata, E Guard cells, F Epidermis, G Xylem, H Phloem
A Epidermis, C Palisade mesophyll, C Spongy mesophyll, D Stomata, E Guard cells, F Phloem, G Metaxylem, H Protoxylem
Lignin is the important constituent in the cell wall of
phloem
parenchyma
xylem
cambium
A common structural feature of vessel elements and sieve tube elements are
pores on lateral walls.
presence of p-protein.
enucleate condition.
thick secondary walls.
Read the following statements and answer the question.
- It has a sclerenchymatous hypodermis, a large number of scattered vascular bundles and a large parenchymatous ground tissue.
- Vascular bundles are conjoint and closed.
- Peripheral vascular bundles are generally smaller than the centrally located ones.
- Phloem parenchyma is absent, and water- containing cavities are present within the vascular bundles.
Which plant anatomy is being described by the above statements?
Dicotyledonous root
Monocotyledonous root
Dicotyledonous stem
Monocotyledonous stem
Which one of the following have vessels as their characteristic feature?
Angiosperms
Gymnosperms
Pteridophytes
Bryophytes
Tissues are classified into two main groups, namely meristematic and permanent tissues on the basis of
whether the cells being able to divide or not.
position of the cells.
whether they are living or dead.
none of the above
A piece of wood having no vessels (trachea) must be belonged to
teak
mango
pine
palm
Which of the following statements are correct ?
- Xylem transports water and minerals.
- Gymnosperms lack sieve tubes and companion cells in phloem.
- The first formed primary xylem is called metaxylem.
- Phloem fibres (bast fibres) are made up of collenchymatous cells.
(i) and (iii)
(i) and (ii)
(iii) and (iv)
(i) and (iv)
Which of the following figure is a type of permanent tissue having many different types of cell?
Match the followings and choose the correct option
| Column-I | Column-II |
|---|---|
| A. Cuticle | I. Guard cells |
| B. Bulliform cells | II. Outer layer |
| C. Stomata | III. Waxy layer |
| D. Epidermis | IV. Empty colourless cell |
A III, B IV, C I, D II
A I, B II, C III, D IV
A III, B II, C IV, D I
A III, B II, C I, D IV
Which type of plant tissue is being described by the given statements?
- It consists of long, narrow cells with thick and lignified cell walls having a few or numerous pits.
- They are dead and without protoplasts.
- On the basis of variation in form, structure, origin and development, it may be either fibres or sclereids.
- It provides mechanical support to organs.
Parenchyma
Sclerenchyma
Collenchyma
Chlorenchyma
Gymnosperms are also called soft wood spermatophytes because they lack
cambium
phloem fibres
thick-walled tracheids
xylem fibres
Identify the types of simple tissue indicated by A, B, C and D and their function.
A Parenchyma, Photosynthesis, Storage and Secretion.
B Sclerenchyma Scleriods; Transport food material
C Collenchyma; Provides mechanical support to organs.
D Sclerenchyma Fibres; Provide Mechanical support to the growing parts of the plant such as young stem and petiole of a leaf.
Which of the following are present in monocot root ?
conjoint, collateral, open polyarch vascular bundle.
exodermis, endarch, tetrarch closed vascular bundles.
suberized exodermis, casparian strip, passage cells, cambium.
suberized exodermis, polyarch xylem, pith.
Identify types of vascular bundles in given figures A, B and C.
Radial; Conjoint closed; Conjoint open
Conjoint closed; Conjoint open; Radial
Conjoint open; Conjoint closed; Radial
Bicollateral; Concentric; Radial
Match column-I with column-II and select the correct option from the codes given below.
| Column-I | Column-II |
|---|---|
| A. Stele | I. Innermost layer of cortex |
| B. Endodermis | II. Suberin |
| C. Casparian strips | III. All the tissues exterior to vascular cambium |
| D. Bark | IV. All the tissues inner to endodermis |
A IV, B I, C II, D III
A III, B II, C I, D IV
A I, B II, C III, D IV
A IV, B II, C I, D III
In the given figure of phloem tissue, identify the marked part (A, B and C) which help in maintaining the pressure gradient
in the sieve tubes.
A
B
C
None of the above
A tissue is a group of cells which are
similar in origin, but dissimilar in form and function.
dissimilar in origin, form and function.
dissimilar in origin, but similar in form and function.
similar in origin, form and function.