52. Phloem Xylem
Occurrence: Roots, stems and leaves Roots, stems and leaves
Additional Functions:
Forms vascular bundles with
xylem
Forms vascular bundles with
phloem and
givesmechanical strength to
plant due to presence of
lignified cells.
Elements:
Sieve tubes, companion cells,
phloem parenchyma, bast
fibers, intermediary cells
Tracheids, vessel elements,
xylem parenchyma, xylem
sclerenchyma
Nature of tissue: Living tissue Non living tissue at maturity
Movement: Bidirectional Unidirectional (upward)
Function:
Transportation of food and
nutrients from leaves
tostorage organs and growing
parts of plant.
Water and mineral transport
from roots to aerial parts of the
plant.
Structure: Tubular with soft walled cells Tubular with hard walled cells
78. Corms are unlike stolons and
rhizomes because they
usually grow vertically,
instead of lying horizontally.
They're unlike tubers in that
tubers are typically attached
to the main plant by a slender
rootlike part of the stem, a
sort of umbilical cord, while
corms constitute the below-
ground "heart" of the plant,
the part from which
aboveground stems and
leaves directly sprout.
Gladiolus
98. Bulbs can be considered to be very short stems
encased in thickened, fleshy bulb scales (which are
modified leaves). As the drawing below shows, the two
basic bulb types are layered and scaly:
99. LAYERED BULBS are composed of a series of
fleshy scales that form concentric rings when the
bulb is cut in cross-section.
100. SCALY BULBS, such as
the lily bulb have fleshy
bulb scales, which are
modified leaves loosely
clustered around the stem
base.
136. These flowers can be classified into :
Regular or Disc Florets
-All petals have same size
-They form the central disk of the capitulum in
typical daisies
-Usually surrounded by an outer ring of ray florets
Disc floret, typical for
flowers of the Family Asteraceae
A. ovary
B. pappus
C. theca
D. ligule
E. style with stamen
137. ●Irregular or Ray Florets
-Usually pistillate or sterile, and have three or
fewer teeth on the extended portion of the corolla
Ray floret, typical for
flowers of the Family Asteraceae
A. ovary
B. pappus
C. theca
D. ligule
E. style with stamen
176. 1. Water – The testa
ruptures when exposed to
water
2. Oxygen – Required for
respiration
3. Heat – suitable
temperature required to
stimulate germination
Seed germination Three factors needed for
seed germination:
