Multiple Choice QuestionsThe annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is
maturing
elongating
widening
widening
In barley stem, vascular bundles are
open and scattered
closed and scattered
open and in a ring
open and in a ring
Vascular tissue in flowering plants develop from
phellogen
plerome
periblem
periblem
B.
plerome
Histogen theory for shoot apical meristem has been proposed by Hastein (1870).It advocates that there are three distinct meristematic zones (layers) called dermatogen periblem and plerome. The dermatogen is the outermost histogen giving rise to the epidermis, periblem is the middle one producing the cortex and plerome is the innermost resulting in the certain cylinder (ie, vascular tissue).
Cork cambium (phellogen) is the secondary lateral meristem found in the outer cortical region. Its cells divide periclinally cutting offf cells towards the outside (formingcork or phellem) and inside (forming secondary cortex or phelloderm).
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
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
Plants which produce characterstic pneumatophores and show vivipary belong to
Mesophytes
Halophytes
Psammophytes
Psammophytes
The vascular cambium normally gives rise to
Phelloderm
Primary phloem
Secondary xylem
Secondary xylem
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
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