Transcript diversity notes 2.2

PLANTS ARE PRODUCERS
• PLANTS CAPTURE ENERGY FROM THE
SUN.
– The sun’s heat & light provide the energy almost all
organisms need to live.
– Light energy must be changed into chemical energy
(the form of energy all organisms use to carry out the
functions of life). Plants capture energy from the Sun
& convert it to chemical energy (via photosynthesis).
• PLANTS ARE ADAPTED TO DIFFERENT
ENVIRONMENTS
• PLANTS RESPOND TO THEIR
ENVIRONMENT
• PLANTS RESPOND TO SEASONAL
CHANGES
PLANTS & SUN
• PHOTOSYNTHESIS:
plants use sunlight to
make chemical energy(in
energy rich sugar
molecule)
• Sunlight + 6CO2
+6H2OC6H12O6 + 6O2
• Most photosynthesis
occurs in leaf, stem holds
it up to sun, and roots
anchor in soil and give
H20.
• AUTOTROPH= selffeeder; another name for
plants
• Algae, some bacteria &
some protists also use
photosynthesis
• Plants are mulitcellular
though & can store more
energy than the others
• Starch = energy rich
molecule made of sugars
plants store energy in.
• Cellular respiration = how
cells break down sugars
for energy release.
(C6H12O6 + 6O2 6CO2
+ 6H2O + energy)
• Some plants store starch
in roots (carrots/beets) &
others in stems (rhubarb)
PLANTS ADAPT TO
DIFFERENT ENVIRONMENT
• Almost all land has some type of plants
• GRASSES: deep roots, quickly makes seeds,
found in most environments (as longs as roots
survive, grass grows back)
• TREES: not survive if leaves/stem die; need lots
water; coniferous (needle-leaves stay green) do
well in cold, deciduous(lose leaves in cold)need
long growing season
• Some plants (desert & snowy mountain) must
reproduce quickly while timing is good for them
(seeds sprout, flowers grow, & new seeds made
within just a few weeks)
PLANTS ADAPT TO
ENVIRONMENTS
• Some plants adapt to
protect: mustard gives off
odor; poison ivy & oak
make chemical & tobacco
makes nicotine (poison)
to keep insects from
eating them.
• Venus fly trap has teeth
on leaf edges to capture
insects & makes digestive
fluid to break insect down
for important materials
not found in local soil
Plants Respond to Environment
• Plants respond to stimuli (change in environment
causing a response) to survive & grow.
• Gravity: roots drawn down & stems grow up,
even if seedling is on its side.
• Touch: “tendrils” (found in peas, & climbing
plants) are special stems that wrap around objects
to grow upward to sun
• Light: stems grow towards it; plant releases auxin
(plant hormone) at tip of stem. This moves away
from light & stimulates cell growth, causing plant
to bend towards the sun.
PLANTS RESPOND TO
SEASONAL CHANGES
• Shorter time of
daylight affects
amount of sunlight
available for
photosynthesis. So
plant goes into
“dormancy”. Plant
stops growing &
needs less energy.
PLANTS RESPOND TO
SEASONAL CHANGES
• In temperate climates, approach of winter causes
leaves of deciduos trees to die & drop to ground.
• In some plants (like trees) they go into dormancy
& grow in spring again; in others (like wild
cornflowers) they die and only grow back in
spring due to seeds left behind.
• Short-day plants (rice/ragweed) only flower in
fall or winter; long-day plants (lettuce/spinach)
flower only in late spring & summer.