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.
Correct Answer :
C. there is no marked climatic variation.
Annual ring is a ring in the cross section of the stem or root of a temperate woody plant, produced by one year's growth. Trees at sea do not have annual rings because there is no marked climatic variation. In climates with well-marked alternations of seasons (either cold and warm or wet and dry), the wood cells produced when water is easily available and growth is rapid (generally corresponding to the spring or wet season) are often noticeably larger and have thinner walls than those produced later in the season when the supply of water has diminished and growth is slower. There is thus a sharp contrast between the small, thick-walled late-season wood cells produced one year, and the large, thin-walled cells of the spring wood of the following year results. Where the climate is uniform and growth continuous, as in wet, tropical forests, there is usually little or no gross visible contrast between the annual rings, although differences exist. When rings are conspicuous, they may be counted in order to obtain a reasonably accurate approximation of the age of the tree. They are also reflective (by their range of thickness) of the climatic and environmental factors that influence growth rates.
Related Questions
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.
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.
A narrow layer of thin walled cells found between phloem/ bark and wood of a dicot is
cork cambium
vascular cambium
endodermis
both (a) & (c)
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 piece of wood having no vessels (trachea) must be belonged to
teak
mango
pine
palm
Bast fibres are made up of _____________cells.
sclerenchymatous
chlorenchymatous
parenchymatous
aerenchymatous
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
Some vascular bundles are described as open because these
are surrounded by pericycle but not endodermis.
are capable of producing secondary xylem and phloem.
possess conjunctive tissue between xylem and phloem.
are not surrounded by pericycle.
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.
Which of the following is responsible for the formation of an embryonic shoot called axillary bud?
Lateral meristem
Apical meristem
Intercalary meristem
Both
Which one of the following have vessels as their characteristic feature?
Angiosperms
Gymnosperms
Pteridophytes
Bryophytes
Identify A, B and C in the given figure of shoot apical meristem
A Leaf primordium, B Shoot apical meristem, C Axillary bud
A Leaf primordium, B Shoot apical meristem, C Apical bud
A Root hair primordium, B Root apical meristem, C Axillary bud
A Root hair primordium, B Root apical meristem, C Terminal bud
Phellogen and phellem respectively denote
cork and cork cambium,
cork cambium and cork,
secondary cortex and cork,
cork and secondary cortex,
Sclerenchyma usually___________and_____________ protoplasts.
live, without
dead, with
live, with
dead, without
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
Choose the correct labelling of (A J) in the given figure of T.S. of monocot root.
A Root hair, B Epiblema, C Cortex, D Endodermis, E Passage cell, F Pericycle, G Pith, H Phloem, I Metaxylem.
A Root hair, B Epiblema, C Cortex, D Endodermis, E Passage cell, F Pith, G Pericycle, H Metaxylem, I Phloem.
A Root hair, B Epiblema, C Cortex, D Endodermis, E Pericycle, F Phloem, G Protoxylem, I Metaxylem
A Root hair, B Cortex, C Epiblema, D Pericycle, E Endodermis, F Pith, G Phloem, H Protoxylem, I Metaxylem
Cork is formed from
phellogen
vascular cambium
phloem
xylem
Sieve tubes are suited for translocation of food because they possess
bordered pits.
no ends walls.
broader lumen and perforated cross walls.
no protoplasm.
Apical, intercalary and lateral meristems are differentiated on the basis of
origin
function
position
development
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.
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
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.
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
A student was given a tissue to observe under the microscope. He observes the tissue and concludes that the tissue is a type of simple plant tissue and provides mechanical support to young stem and petiole of leaf.
Identify the tissue.
Parenchyma
Collenchyma
Sclerenchyma
Xylem parenchyma
Main function of lenticel is
transpiration
guttation
gaseous exchange
both (a) & (c)
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.
In stems, the protoxylem lies towards the _____________ and the metaxylem lies towards the ____________ of the organ.
centre; periphery
periphery; centre
periphery; periphery
centre; centre
Match the terms given in column I with their funciton given in column II and choose the correct option.
| Column-I | Column-II |
|---|---|
| (Term) | (Functions) |
| A. Meristem | I. Photosynthesis, storage |
| B. Parenchyma | II. Mechanical support |
| C. Collenchyma | III. Actively dividing cells |
| D. Sclerenchyma | IV. Stomata |
| E. Epidermal tissue | V. Sclereids |
A I, B III, C V, D II, E IV
A III, B I, C II, D V, E IV
A II, B IV, C V, D I, E III
A V, B IV, C III, D II, E I
Why grafting is successful in dicots ?
In dicots vascular bundles are arranged in a ring.
Dicots have cambium for secondary growth.
In dicots vessels with elements are arranged end to end.
Cork cambium is present in dicots
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