In axile placentation, the ovules are attached to a central column in a multilocular ovary. Tomato, lemon, and China rose are classic examples.
117. Plants identical to mother plants can be obtained from:
(a) its seeds
(b) its fruits
(c) stem cutting
(d) hybridization
Answer:
(c) stem cutting
Explanation:
Stem cutting is a form of vegetative (asexual) propagation. Because there is no mixing of gametes, the resulting plants are exact genetic clones of the mother plant.
118. The central cell, following triple fusion differentiates into:
(a) Zygote
(b) Suspensor
(c) Primary endosperm cell (PEC)
(d) Embryo
Answer:
(c) Primary endosperm cell (PEC)
Explanation:
Following triple fusion (fusion of a male gamete with two polar nuclei), the central cell of the embryo sac becomes the Primary Endosperm Cell (PEC), which later develops into the endosperm.
119. Hygroscopic nature of the endothecium is primarily due to :
(a) presence of callose bands
(b) thin outer walls
(c) fibrous thickening of cellulose
(d) Absence of stomium
Answer:
(c) fibrous thickening of cellulose
Explanation:
The endothecium layer in anther walls develops fibrous thickenings composed of alpha-cellulose. These bands are hygroscopic and help in the dehiscence of the anther upon drying.
120. Which of the following is not an invasive alien species in the Indian context?
(a) Lantana
(b) Parthenium
(c) Eichhornia
(d) Cynodon
Answer:
(d) Cynodon
Explanation:
Cynodon dactylon (Bermuda grass) is a common, widespread grass not typically classified alongside destructive “invasive alien” weeds like Lantana, Parthenium (carrot grass), and Eichhornia (water hyacinth).
