Why are vascular bundles closed in monocots?
(1) Xylem and Phloem are present
(2) Xylem and phloem occur in separate bundles
(3) Vascular cambium is present between xylem and phloem
(4) Vascular cambium is not present
Given figure shows:-
(a) structure of lenticel
(b) hydathode showing gaseous vapour exchange
(c) fungus reproducing by spore formation
(d) algae reproducing by spore formation
Select the correct pair amongst the following.
(1) Spring wood - light colour, high density
(2) Spring wood - dark colour, low density
(3) Autumn wood - light colour, high density
(4) Autumn wood - dark colour, high density
As secondary growth proceeds, in a dicot stem, the thickness of.
(1) sapwood increases
(2) heartwood increases
(3) both sapwood and heartwood increases
(4) both sapwood and heartwood remains the same
The desert grasses, often curls their leaf to minimise water loss due to presence of
(2) Palisade parenchyma
(3) Bundle sheath cells
(4) Bulliform cells
Tyloses are balloon-like outgrowths in the lumen of secondary xylem tracheids and vessel of duramen region. These are actually:-
(1) outgrowth of vessels of xylem
(2) ingrowth of vessels
(3) outgrowth of parenchymatous cell
(4) swelling of xylem fibres for no function
Pith cavity occurs in the stem of ?
(2) Zea mays
Match the Column I and II.
A. Bulliform cells
B. Guard cells
2. Aerating pore
3. Accessory cells
D. Subsidiary cell
4. Isobilateral cells
A B C D
(a) 1 2 3 4
(b) 3 1 2 4
(c) 4 1 2 3
(d) 4 3 2 1
Root cambium is derived from?
(1) primary meristem
(2) secondary meristem
(3) intercalary meristem
(4) apical meristem
Which one of the following comprises only simple tissue?
A. Parenchyma, Collenchyma and Sclerenchyma
B. Parenchyma, Xylem and Collenchyma
C. Parenchyma, Xylem and Sclerenchyma
D. Parenchyma, Xylem and Phloem