General
✓✗Collenchyma differs from parenchyma in having
- thickening of cellulose, hemicellulose and pectin at the corners
- thin cellulose walls with small intercellular spaces
- living protoplasm with a central vacuole and nucleus
- lignified secondary walls with numerous simple pits
General
✓✗Gaseous exchange in submerged hydrophytes takes place through
- hydathodes at the leaf margins
- the general surface of the plant
- lenticels present in the bark
- stomata on the upper epidermis
General
✓✗As the stem continues to increase in girth due to the activity of the vascular cambium, the outer cortical and epidermal layers
- keep expanding indefinitely without any damage
- get broken and need to be replaced by new protective layers
- become meristematic and form the vascular cambium
- are converted into secondary xylem by the cambium
General
✓✗Mesophyll belongs to which tissue system?
- Epidermal tissue system
- Vascular tissue system
- None of the tissue systems
- Ground tissue system
General
✓✗Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Root hairs help in the absorption of water and minerals.
Reason (R): Root hairs are multicellular outgrowths of the cortex.
In the light of the above statements, choose the correct answer from the options given below.
Assertion (A): Root hairs help in the absorption of water and minerals.
Reason (R): Root hairs are multicellular outgrowths of the cortex.
In the light of the above statements, choose the correct answer from the options given below.
- (A) is true but (R) is false.
- (A) is false but (R) is true.
- Both (A) and (R) are true and (R) is the correct explanation of (A).
- Both (A) and (R) are true but (R) is not the correct explanation of (A).
General
✓✗Primary growth of a plant is brought about by
- apical meristems
- vascular cambium
- cork cambium
- interfascicular cambium
General
✓✗The cells of the epiblema of the root protrude in the form of
- trichomes
- scales
- unicellular root hairs
- lenticels
General
✓✗Which lateral meristem develops in the cortex of a dicot stem during secondary growth?
- Shoot apical meristem
- Intercalary meristem
- Cork cambium
- Intrafascicular cambium
General
✓✗Spring wood is lighter in colour and has a lower density because
- the cambium is less active and produces fewer elements
- it is formed only of fibres
- it contains tannins and resins
- the cambium is very active and produces many xylary elements with wider cavities
General
✓✗Which of the following pairs is incorrectly matched?
- Cuticle - prevents water loss
- Subsidiary cells - store food for guard cells
- Trichomes - prevent water loss by transpiration
- Root hairs - absorb water and minerals
General
✓✗In a dicot root, the endodermal cells are
- elongated, pointed and thick-walled, occurring in groups
- loosely arranged, with large air spaces and many chloroplasts
- dead and lignified on all walls, without any protoplasm
- barrel-shaped, without intercellular spaces, with Casparian strips on radial and tangential walls
General
✓✗How many of the following are found in a typical dicot stem?
Collenchymatous hypodermis, starch sheath, semi-lunar sclerenchymatous pericycle, medullary rays, bulliform cells, scattered vascular bundles, endarch protoxylem
Collenchymatous hypodermis, starch sheath, semi-lunar sclerenchymatous pericycle, medullary rays, bulliform cells, scattered vascular bundles, endarch protoxylem
- Three
- Four
- Six
- Five
General
✓✗The activity of sieve tube elements is controlled by the nucleus of the
- phloem parenchyma
- phloem fibres
- albuminous cells
- companion cells
General
✓✗Radial vascular bundles occur in
- monocot roots only
- dicot stems
- both dicot and monocot roots
- dicot roots only
General
✓✗Given below are two statements.
Statement I: In a dicotyledonous leaf, the adaxial epidermis generally bears more stomata than the abaxial epidermis.
Statement II: In a dicotyledonous leaf, the adaxially placed palisade parenchyma is made up of elongated cells, which are arranged vertically and parallel to each other.
In the light of the above statements, choose the correct answer from the options given below.
Statement I: In a dicotyledonous leaf, the adaxial epidermis generally bears more stomata than the abaxial epidermis.
Statement II: In a dicotyledonous leaf, the adaxially placed palisade parenchyma is made up of elongated cells, which are arranged vertically and parallel to each other.
In the light of the above statements, choose the correct answer from the options given below.
- Both Statement I and Statement II are correct.
- Both Statement I and Statement II are incorrect.
- Statement I is correct but Statement II is incorrect.
- Statement I is incorrect but Statement II is correct.