The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is
maturing
elongating
widening
widening
C.
widening
Vessel or tracheae are made up of a row of cells, placed one above the other, with their intervening walls absent or variously pored. The walls of vessels are lignified and hard, but not very thick. The cell cavity or the lumen is wide. The thickening may be annuler, spiral, scalariform, reticulate and pitted.
Identify the wrong statement in context of heartwood.
Organic compounds are deposited in it
It is highly durable
It conducts water and minerals efficiently
It conducts water and minerals efficiently
Plants which produce characterstic pneumatophores and show vivipary belong to
Mesophytes
Halophytes
Psammophytes
Psammophytes
A common structural feature of vessel elements and sieve tube elements is
thick secondary walls
pores on lateral walls
presence of P-protein
presence of P-protein
In barley stem, vascular bundles are
open and scattered
closed and scattered
open and in a ring
open and in a ring
For a critical study of secondary growth in plants. which one of the following pairs is suitable?
Sugarcane and sunflower
Teak and pine
Deodar and fern
Deodar and fern
The vascular cambium normally gives rise to
Phelloderm
Primary phloem
Secondary xylem
Secondary xylem
