Plant Diversity
The Evolution and
Classification of
Plants
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Warm-up: Write each Question and Answer for Each.
What do I know about plants?
True or False
1. All plants perform photosynthesis.
2. All plants need water and nutrients.
3. All plants reproduce using flowers.
4. All plants reproduce using seeds.
Slide # 3
PLANT CHARACTERISTICS
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Multicellular
Eukaryototic
Autotrophic
Non-mobile (fixed to one spot)
Cell walls made of cellulose
Responds to environment
Grows through the use of hormones
Slide # 4
Plants Make the Move to Land
The ancestors of plants were:
multicellular green algae.
Problems to solve:
1. How to transport resources within the plant.
2. How to prevent from drying out
3. How to reproduce without water
Slide # 5
Some Adaptations (solutions)-
1. Roots and shoots to reach water and sunlight
2. vascular system to transport resources in
plant
3. cuticle (waxy outer layer) to keep from drying
out
4. spores & seeds that do not dry out for
reproduction
Slide # 6
Plants are classified based on
whether or not they have
1. Vascular System (transport)
2. Seeds
3. Flowers (for reproduction)
Slide # 7
Concept Map: Plants are divided 1st by
whether or not they have a vascular system.
Plants
NO Vasc Tissue
Bryophytes
Vascular Tissue
Tracheophytes
Slide # 8
Bryophytes
NONVASCULAR
1. Most common example: Mosses
2. Primitive plants
3. Found in moist, shady areas
4. NO vascular (transport) system
5. Small size due to no vascular tissue
6. No true roots, stems, or leaves
7. Needs water for reproduction.
8. Reproduces using spores, -a water-proof
single cell that can grow into a new organism.
Slide # 9
Typical Moss Plant
(most common bryophyte)
Spores form inside the
capsule.
Slide # 10
Tracheophytes
-Vascular Plants-
1. vascular tissues for transport :
a. Xylem- transports H20 up from roots.
b. Phloem- transports food made during
photosynthesis to where they are needed.
2. Tall due to presence of a vascular system.
3. Has roots, stems, and leaves.
Slide # 11
Tracheophytes are divided into two groups by
whether or not they reproduce with seeds.
Tracheophytes
Seedless
Ferns use
spores
Seeded
Slide # 12
The Fern - a seedless vascular
plant
1. Vascular system.
2. Has stems, roots,
3. Reproduce using
spores.
There are 11,000 species
of ferns.
Tracheophytes
Seedless
Ferns use
spores
Seeded
Gymnosperms
Angiosperms
“naked” or
exposed
seeds
Flowers produce
fruit w/ enclosed
seeds
Gymnosperms- “naked
Cycad (Sago palm), seed”
Slide # 15
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• Ginkgo,
• Conifer (pine, spruce, firs, cedars, sequoias,
redwoods, junipers, yews, & cypress trees)
Sago Palm
Ginkgo
Ginkgo
Sequoia
Slide # 16
Gymnosperms-Conifers
Conifers have needles for leaves
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have a reduced surface area
• thick waxy coat on the needle to
reduce water loss and prevent
freezing.
Pine
Juniper
Conifer
Reproduction
Slide # 17
1. Male cones produce
pollen and the female
cones produce eggs.
2. Pollen is transferred
by the wind.
3. Seeds grow in female
cones.
Pollen
Cone
Pollen
Seed
Cone
Slide # 18
Angiosperms- “enclosed seeds”
1. flowering plants
2. Flowers: where egg and sperm are
produced
3. Flowers provide direct and efficient pollen
transfer
4. Pollinators: flying insects, birds, and bats
5. Fruit is the mature ovary containing
seeds.
From flower to seedling:
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Egg and sperm are produced in flower
Sperm is packaged into pollen
Pollen delivered to another flower by pollinator
Pollen fertilizes egg
Egg develops into seed
Ovary develops into fruit around seed
Animal eats fruit and deposits seed
Seedling grows from seed.
Quiz Time
• What did plants have to overcome to live on
land?
• What is the most primitive division of plants
because they have no vascular system?
• Why are mosses so small?
• What is the division of plants that contain a
vascular system?
• What did a vascular system do for plants sizewise?
• How are mosses and ferns different?
• How are mosses and ferns alike?
Quiz Time
• What are the two divisions of the seed-bearing
tracheophytes?
• What does the term Gymnosperm mean?
• What is the evolutionary importance of needles?
• What structures do conifers use to reproduce?
• Even though wind-dispersal of pollen is inefficient,
what did it allow plants to overcome?
• What is the evolutionary advantage of a flower?
• How does the fruit help disperse the seed in
angiosperms?