Download Introduction to Plants

Introduction to
Plants
Classification of plants
• Kingdom Plantae
– Phylums
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Lycodiophyta (Club Mosses)
Equisetophyta (Horsetails)
Psilotophyta (Wisk Ferns)
Polypodiophyta (Ferns)
Cycadophyta (Cycads)
Ginkgophyta (Ginkoes)
Pinophyta (Conifers)
Gnetophyta (Vessel-bearing Gymnosperms)
Magnoliophyta (Flowering Plants)
Facts…
• critical to other life on this planet because they
form the basis of all food webs
• Most plants are autotrophic
• earliest fossils found have been aged at 3.8
billion years
• scientific study of plants, known as botany
• identified about 350,000 extant (living) species
of plants
– ~258,650 are flowering and ~18,000 bryophytes
What are plants?
• Multi-cellular
organisms
• Make own food
(photosynthesis)
• Have chloroplasts
• Have rigid cell walls
made of cellulose
• Found all over the
world
Plants provide:
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Food
Oxygen
Medicines
Building
materials
• Textiles (fibers)
• Coloring
pigments
Plant Classification
Plants
With seeds
Gymnosperms
"naked seeds"
cones, no flowers
needle-like leaves
EX: Ginko
Without seeds
need water to
reproduce;
spores
Angiosperms
flowering plants
largest group
EX: conifers
Monocots
Mosses
Dicots
EX: grasses EX: orchids EX: oak tree EX: broccoli
Ferns
Liverworts
Horsetails
Plants Without Seeds
• Need water to reproduce
• Reproduce with spores
• Include
–Mosses
–Ferns
–Horsetails
–Bladderworts
Plants with Seeds
• 2 types
• Found all over the world
Gymnosperms
• Means “naked seed”
• Often have cones & needle-like
leaves
• Do not have flowers
–Ex: conifers, gingko
Angiosperms
• Flowering plants
• Largest group
– Moncots
– Dicots
Monocots
Dicots
Evolution
• Principal photosynthetic organisms were
microscopic cells floating below the surface of
the water, closer to the sun’s rays
• As they multiplied, depleted resources of the
open ocean, so colonies could be found nearer
to the shores, in order to get minerals and
nutrients from runoff
• About 650million years ago, diversity of these
organisms abounded on the rocky shores, and
some even integrated into multicelluar bodies
Evolution
• These new multicelluar photosynthetic
forms developed a cell wall due to the
rough waters of the rocky coastline
• As size increased, they developed internal
structures that linked the
photosynthesizing parts to the nonphotosynthesizing parts
Evolution to land..
• Oxygen & carbon dioxide not as abundant
in the water, as it is not as free circulating
as it is on land
• Critical factor to adapting to land is water
resources
• Development of root systems to be able to
keep plant stable on land and to seek out
water resources without moving
Roots
What do they do for
the plant???
Are you Rooted?
• Roots help to keep plants in place.
• They spread out into the soil and
“attached” themselves to the particles of
the soil.
• Why do they reach and probe?
– To find nutrients and water, thus in the end the
plant gets anchored into the soil.
Root Hairs
• Water in the soil is
taken up by root hairs
and then passes from
cell to cell to the
xylem.
Types of Roots
Fibrous Roots
• Generally grasses
have this type of
root
• Many roots extend
into the soil from
base of plant
Tap Roots
• One or more large
roots extending
into the soil
• Smaller roots
branch off
Types of Roots
• Shallow roots
– Desert roots
– Quickly growing
plants
• Deep
underground
roots
– Areas with little
rainfall
• Deep and Shallow
Roots
– Takes
advantage of
underground
water sources
and occasional
showers.
Root Growth
What does it depend on?
• Amount of moisture in the soil
• Type of soil
• How quickly the plants grow and go to
seed
• Type of rainfall in that area
• Type of plant – prop roots are used to
help support the plant
Lastly…
• Roots are used as food storage for
plants. They store sugars and
starches to help plants over winter.
• Sugar storage in roots also help to
send up new shoots each spring, and
to regenerate stems and leaves that
were eaten or burned.
• Radishes, carrots, turnips – store
large amounts of food in the form of
starch in their roots. We eat these
roots as a source of energy.
Plant Functions
What do stems & leaves do for a
plant???
Stems
Transport of Materials
• Phloem (2)
– Carries sugars (food)
up & down in plant
• Xylem (1)
– Carries water &
mineral up from roots
to all parts of plants
Leaves
Photosynthesis
• Leaves collect
sunlight, water and
carbon dioxide to
make sugar (food) for
the plant
• The chemical
equation for this
process is
6 H2O + 6 CO2 
C6H12O6 + 6 O2
sugar
• Leaves break down
sugars to get energy
• This process releases
excess water as
waste
• The chemical
equation is
• C6H12O6 + 6 O2
energy + 6 H2O + 6
CO2
sugar
To help plant grow
Energy released
Respiration
Transpiration
• Taking in CO2 and releasing O2 and H2O as
waste products after respiration