Vascular tissues in flowering plants develop from
Phellogen
Plerome
Periblem
Dermatogen
B.
Plerome
C.
Periblem
Histogen theory for shoot apical meristem has been proposed by Hanstein (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 on producing the cortex and plerome is the innermost resulting in central cylinder (i.e., vascular tissue).
Cork cambium (phellogen) is the secondary lateral meristem found in the outer cortical region. Its cells divide periclinally cutting off cells towards the outside (forming cork or phellem) and inside (forming secondary cortex or Phelloderm).
In which one of the following, the male and female gametophytes don’t have free-living independent existence?
Pteris
Funaria
Polytrichum
Cedrus
During the propagation of a nerve impulse, the action potential results from the movement of
K+ ions from extracellular fluid to intracellular fluid
Na+ ions from intracellular fluid to extracellular fluid
K+ ions from intracellular fluid to extracellular fluid
Na+ ions from extracellular fluid to intracellular fluid
In mitochondria, enzyme cytochrome oxidase is present in
Outer membrane
Perimitochondrial space
Inner Membrane
Matrix
Nitrogen-fixation in root nodules of Alnus is brought about by
Bradyrhizobium
Clostridium
Frankia
Azorhizobium
Darwin’s finches are an excellent example of
Adaptive Radiation
Seasonal migration
Brood parasitism
Connecting links
