PLANTS
• PLANTS ARE ADAPTED TO LIVING
ON LAND
• MOST MOSSES AND FERNS LIVE IN
MOIST ENVIRONMENTS
• SEEDS AND POLLEN ARE
REPRODUCTIVE ADAPTATIONS
• MANY PLANTS REPRODUCE WITH
FLOWERS AND FRUIT.
PLANTS ARE ADAPTED TO
LIVING ON LAND
• Plants are a diverse group of organisms.
• Plants share common characteristics
• Plant parts have special functions
– Roots: anchor plant in ground, absorb water &
nutrients from soil (transported to leaves via
stems)
– Stems & Leaves: make up shoot system; leaves use
materials from roots & CO2 from air to make
sugars/carbohydrates (& O2); stems then deliver
these energy-rich compounds back to rest of plant
• Plants grow throughout their lifetimes.
PLANTS ARE DIVERSE
• Plants are nearly
everywhere; they come in
all sizes, & shapes.
• Plants are found in all
types of environments,
from icy arctic to steamy
tropics
Share Common Characteristics
• Plants are multi-cellular organisms
• A plant cell has a nucleus and is
surrounded by a cell wall.
• Plants are producers. They capture Energy
from the Sun.
• Plant life cycles are divided into 2 stages,
or generations.
Special Functions
• In most plants, materials move through a
vascular system in the stems, made of long,
tubelike cells.
• Xylem tissue are big tubes taking water &
nutrients up to leaves. Phloem tissue are
smaller &take sugars/carbs down from leaves.
Special Functions
• Plants make sugars via photosynthesis, which
takes place in green chloroplasts full of
chlorophyll(absorbs sunlight, mostly in upper
leaf); vascular tissue in center of leaf brings in
WATER & NUTRIENTS and carries away
SUGAR/CARBS;
• Tiny openings at bottom of leaf (STOMATA)
lets in CO2 gas & stores it as oxygen is released.
(this is known as gas exchange)
• 6CO2 + 6H20 + sunlight C6H1206 + 6O2
• Stomata also let water evaporate out of the
leaf(this is called transpiration); both sunlight &
wind cause water to transpire/evaporate.
SPECIAL FUNCTIONS
• Surface of leaf & stem
has waxy protective layer
(cuticle), keeping water
from evaporating.
• When air is dry, stomata
can close.
• Spines of cactus are
modified leaves (regular
leaves would loose too
much water);
photosynthesis occurs in
the fleshy green stem,
which also stores water &
carbon dioxide gas.
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Plants
Grow
throughout
Life
Plants continue to grow till die (cells at tips of
roots & stems divide quicker)
Leaves only grow on stems from growth tissue.
Stems have vascular system(to transport materials
between leaf & root) which gives support through
stiff fibers and gives plant its shape. Can also store
sugars made by photosynthesis (broccoli).
Soft stem plants have stems & leaves that die in
bad weather but roots survive (store sugar) to regrow stems & leaves back in good weather.
Woody Stem plants have stems that don’t die each
year but grow longer & thicker; form special xylem
called “wood”; growing tissue near outer surface
(so older wood in middle of tree).