Scribe Post 3-12-12
Today in Class We:
~Watered and Measured Fast Plants
~Notes (Ch. 28: Flowering Plants)
Know Monocots vs. Dicots for Lab!!
*Memorize these characteristics below*
Roots: Root hairs-increase
surface area of root for
absorption.
Large taproots - store food
such as starch for plant (Ex:
carrots, turnips, sugar beets,
sweet potatoes................................Monocot Root --->
<--- Dicot Root
.................................................................................................................................
Stems - Terminal bud is at apex of stem
when plant stem is growing in length.
Axillary buds, in angle formed by a leaf
(and stem) are dormant.
Terminal bud produces hormones
inhibiting growth of axillary buds = apical
dominance, so plant can grow up to sun.
Axillary buds begin growing and develop
into branches under certain conditions.
Types of Stems
Runner in a strawberry plant = horizontal
stem - new plants emerge from tip of
runner = asexual reproduction
Rhizome of an iris plant =horizontal
underground stems = store food, & can
bud new plants
Tubers are rhizomes ending in enlarged
structures (potatoes). Eyes of potato are
axillary buds, can grow when planted.
Leaves - flat blades (for light collection) and
petioles (joins leaf to stem.) Celery is a big
petiole.
Tendrils = modified leaves for climbing
and support .
Spines of a cactus = modified leaf parts
protecting plant. Cactus stem is
photosynthetic.
2 Plant Vascular Tissues:
1. Xylem - contains water conducting cells -
move water & minerals up stem
2. Phloem -contains food conducting cells -
transport sugars from leaves or storage tissue
to other parts of plant
3 Tissue Systems continuous throughout
plant:
1. Dermal-covers, protects, waxy coating
(epidermis)
2. Vascular- xylem and phloem; support,
transport
3. Ground - bulk of young plant, fills spaces
between epidermis and vascular.
Photosynthesis, storage, support.
Types of ground tissue:
Cortex - in root,cells store food, take up
water & minerals.
Endodermis - selective barrier in cortexdetermines which substances pass between
cortex and vascular tissue.
Pith - fills center of stem in dicots, food
storage.
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