The balloonshaped structures called tyloses
originate in the lumen of vessels
characterise the sapwood
are extensions of xylem parenchyma cells into vessels
are linked to the ascent of sap through xylem vessels.
How many histogens are present at the apex of root
Vascular bundles in monocotyledons are considered closed because :
In which of the following, there is no differentiation of bark, sapwood and heartwood?
$I.$ Sunflower seed
$II.$ A wheat leaf
$III.$ Pea plant
$IV.$ Leaf blade of grass
Bulliform cells are present in which of the above plants?