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
Correct Answer :
C. C
In the given fig. of phloem tissue A, B & C are respectively sieve tube, phloem parenchyma and campanion cells. Companion cells (c) are specialized parenchymal cells adjacent to a sieve tube in the phloem of flowering plants. It is beliveved to regulate the flow of nutrients through the tube.
Related Questions
Match the elements of xylem given in column I with their character given in the column II and choose the correct option.
| Column-I | Column-II |
|---|---|
| A. Xylem vessels | I. Store food materials |
| B. Xylem tracheids | II. Obliterated lumen |
| C. Xylem fibres | III. Perforated plates |
| D. Xylem parenchyma | IV. Chisel-like ends |
A IV; B III; C II; D I
A III; B II; C I; D IV
A II; B I; C IV; D III
A III; B IV; C II; D I
Cambium is considered as a lateral meristem because
it gives rise to lateral branches.
it causes increase in girth.
it increases height and diameter of a plant.
it adds bulk to a plant.
Xylem functions as a conducting tissue for water and minerals from _________to the ______and__________.
roots, stems, leaves
stems, roots, leaves
leaves, stems, roots
leaves, stems, leaves
Read the following statements and answer the question.
- Cambium is very active and produces a large number of xylary elements having vessels with wider cavities.
- It is also called early wood.
- It is lighter in colour and has lower density.
Which type of wood is described by the above statements?
Sap wood
Heart wood
Spring wood
Autumn wood
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)
Sieve tubes are suited for translocation of food because they possess
bordered pits.
no ends walls.
broader lumen and perforated cross walls.
no protoplasm.
Trees at sea do not have annual rings because
soil is sandy.
there is climatic variation.
there is no marked climatic variation.
there is enough moisture in the atmosphere.
Apical, intercalary and lateral meristems are differentiated on the basis of
origin
function
position
development
Cells of permanent tissues are specialized
functionally.
only structurally.
both structurally and functionally.
for mitosis.
Which one of the following have vessels as their characteristic feature?
Angiosperms
Gymnosperms
Pteridophytes
Bryophytes
When we peel the skin of a potato tuber, we remove
periderm
epidermis
cuticle
leaves
Which of the following is responsible for the formation of an embryonic shoot called axillary bud?
Lateral meristem
Apical meristem
Intercalary meristem
Both
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
Phellogen and phellem respectively denote
cork and cork cambium,
cork cambium and cork,
secondary cortex and cork,
cork and secondary cortex,
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.
Cork is formed from
phellogen
vascular cambium
phloem
xylem
Bast fibres are made up of _____________cells.
sclerenchymatous
chlorenchymatous
parenchymatous
aerenchymatous
The given figure shows apical meristem of root apex with few part marked as A, B and C. Identify the correct labelling of A, B and C.
A Vascular structure, B Protoderm, C Root cap
A Cortex, B Endodermis, C Root cap
A Cortex, B Protoderm, C Root cap
A Tunica, B Protoderm, C Root cap
Which of the following statement(s) is/are correct ?
- Uneven thickening of cell wall is characteristic of sclerenchyma.
- Periblem forms cortex of the stem and the root.
- Tracheids are the chief water transporting elements in gymnosperms.
- Companion cell is devoid of nucleus at maturity.
- The commercial cork is obtained from Quercus suber.
(i) and (iv) only
(ii) and (v) only
(iii) and (iv) only
(ii), (iii) and (v) only
T.S. of monocot leaf is given below, certain parts have been marked by alphabets (A G). Which one is the option showing there correct labelling?
A Adaxial epidermis, B Xylem, C Mesophyll, D Sub-stomatal cavity, E Abaxial epidermis, F Stoma, G Phloem
A Adaxial epidermis, B Abaxial epidermis, C Xylem, D Sub-stomatal cavity, E Stoma, F Mesophyll, G Phloem
A Adaxial epidermis, B Phloem, C Mesophyll, D Sub-stomatal cavity, E Abaxial epidermis, F Xylem, G Stoma
A Adaxial epidermis, B Xylem, C Stoma, D Substomatal cavity, E Abaxial epidermis, F Phloem, G Mesophyll
The length of different internodes in a culm of sugarcane is variable because of
size of leaf lamina at the node below each internode
intercalary meristem
shoot apical meristem
position of axillary buds
Main function of lenticel is
transpiration
guttation
gaseous exchange
both (a) & (c)
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
Which meristem helps in increasing girth?
Lateral meristem
Intercalary meristem
Primary meristem
Apical meristem
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.
T.S. of dicot stem is given below, certain parts have been marked by alphabets (A I). Choose the option which shows their correct labelling.
A Epidermis, B Epidermal hair, C Parenchyma, D Starch sheath, E Hypodermis (collenchyma), F Vascular bundle, G Bundle cap, H Medulla or pith, I Medullary rays
A Epidermal hair, B Epidermis, C Hypodermis (collenchyma), D Parenchyma, E Endoderm is (Starch Sheath), F Pericycle, G Vascular bundle, H Medullary rays, I Medulla or pith
A Epidermal hair, B Epidermis, C Hypodermis (collenchyma), D Starch sheath, E Parenchyma, F Vascular bundle, G Bundle cap, H Medulla or pith, I Medullary rays
A Epidermal hair, B Epidermis, C Parenchyma, D Hypodermis (collenchyma), E Starch sheath, F Vascular bundle, G Bundle cap, H Medulla or pith, I Medullary rays
One of the primary function of the ground tissue in a plant is
photosynthesis.
to protect the plant.
to anchor the plant.
water and sugar conduction.
Apical and intercalary meristems are primary meristems because
they occur in the mature region of roots and shoots of many plants.
they made up of different kinds of tissues.
they involved in secondary growth.
they appear early in life of a plant and contribute to the formation of the primary plant body.
A piece of wood having no vessels (trachea) must be belonged to
teak
mango
pine
palm
In stems, the protoxylem lies towards the _____________ and the metaxylem lies towards the ____________ of the organ.
centre; periphery
periphery; centre
periphery; periphery
centre; centre