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
Match the following
|C.||Collenchyma||iii.||Actively dividing cells|
A. A-i, B-iii, C-v, D-ii, E-iv
B. A-iii, B-i, C-ii, D-v, E-iv
C. A-ii, B-iv, C-v, D-i, E-iii
D. A-v, B-iv, C-iii, D-ii, E-i
What is the destiny of primary xylem in a dicot root showing extensive secondary growth?
A. It is retained in the centre of the axis
B. It gets crushed
C. May or may not get crushed
D. It gets surrounded by primary phloem
Which one of the following cell types always give rise to secondary cortex?
A. fusiform initial cells
B, root cap