Transcript Plant Divisions

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
• Multicellular eukaryotes
• Photosynthetic autotrophs containing
chloroplasts.
• Non-mobile (fixed to one spot)
• Cell walls made of cellulose
• Responds to environment and grows
through the use of hormones
Slide # 4
Plants Make the The Move to Land
The ancestors of plants were multicellular green algae. They
were completely immersed in water & dissolved minerals.
To move onto land, plants had to solve these problems:
1. How to get chemical resources (water, minerals,
oxygen, and carbon dioxide) separated into air and
soil
2. How to transport resources within the plant.
3. How to prevent from drying out
4. How to reproduce without water
Slide # 5
Some Adaptations (solutions)-
1. Have body parts extending into both air and
soil
2. Develop a vascular system to transport
resources in plant
3. Have a protective layer – cuticle (waxy outer
layer) to keep from drying out
4. Specialized structures for reproduction
including spores & seeds that do not dry out
Slide # 6
Plants are classified based on
whether or not they have
1. Vascular System (transport)
2. Seeds
3. Flowers (enclosed seeds)
Slide # 7
Concept Map: Plants are divided 1st by
whether or not they have a vascular system.
Plants
Has NO Vascular
Tissue
Bryophytes
Has Vascular
Tissue
Tracheophytes
Slide # 8
Bryophytes
-
NONVASCULAR
1. Most primitive plants
2. Found in moist, shady areas
3. NO vascular (transport) system
4. Small size due to no vascular tissue
5. No true roots, stems, or leaves
6. Needs water for reproduction.
7. Reproduces using spores, -a water-proof
single cell that can grow into a new organism.
8. Most common example: Mosses
Slide # 9
Typical Moss Plant
(most common bryophyte)
Spores form inside the
capsule.
Notice the problem of nutrient
separation into air and soil is
solved with underground and
above ground parts.
(Although NO TRUE roots,
stems or leaves are present)
Slide # 10
Tracheophytes
-Vascular Plants-
1. Contains two types of specialized vascular
tissues for transport within the plant:
a. Xylem- transports H20 up from roots.
b. Phloem- transports food made during
photosynthesis and nutrients to where they are
needed in the plant.
2. Presence of a vascular system allowed plants to
become tall.
3. Has specialized organs: 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. Contain a vascular
system.
2. They grow in moist,
shady habitats.
3. Has underground
stems, roots, & large
leaves called fronds.
4. Reproduce using
spores, Not seeds.
Sori
There
are
11,000
species
of ferns.
Slide # 13
Seed-Bearing Tracheophytes
ADVANTAGE: Developed reproductive
strategies that do not need water:
1. Seed contains
a. A fully developed embryo
b. Food supply for embryo
c. A water-proof seed coat to keep from drying out
2. Sperm transferred in water-proof pollen
through pollination by wind or animals.
3. Developed seed-bearing structures: Cones
and Flowers
The two Seeded Tracheophyte groups are
divided by whether or not they have enclosed
seeds -protected inside a fruit or if seeds are
exposed to the environment.
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
•
• Ginkgo,
• Conifer (pine, spruce, firs, cedars, sequoias,
redwoods, junipers, yews, & cypress trees)
Sago Palm
Ginkgo
Ginkgo
Sequoia
Slide # 16
Gymnosperms-Conifers
1. Most common gymnosperms are
Conifers
2. Conifers have leaves called
needles or scales have a reduced
surface area and thick waxy coat
on the needle to reduce water loss
and prevents freezing.
Pine
Juniper
Slide # 17
Conifer
Reproduction
1. Male cones produce
pollen and the female
cone produces eggs and
seeds.
2. Pollen is inefficiently
transferred by the wind.
3. Once mature, the scales
on the female cone dry
out and open scattering
the seeds by the wind.
Pollen
Cone
Pollen
Seed
Cone
Slide # 18
Angiosperms- “enclosed seeds”
1. These are flowering plants the encourage
direct and efficient pollen transfer (smell,
color and offering nectar)
2. Pollinators are flying insects, birds, and
bats that transfer pollen from flower to
flower.
3. Flowers contain ovaries, which is where
eggs/seeds are produced.
4. A fruit is the pollinated ovary containing
mature seeds.
Slide # 19
Fruit can aid in dispersal of seed to
reduce competition with parent plant.
1. Winged fruit – glides to
new location (maple fruit)
2. Floating fruit – can float to
new locations (coconut)
3. Fleshy fruit - sweet bright
colored fruit have seeds
that survive the digestive
system of animals that eat
the fruit (apple)
4. Spiny fruit- Velcro like
projections attach to the fur
of animals (cockleburs)
Maple seeds: Winged fruit
Burdock: Spiny fruit
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?
• What is the most common example in this division
and how do they reproduce?
• Why are mosses so small?
• What is the division of plants that contain a vascular
system?
• What did a vascular system do for plants size-wise?
• How are mosses and ferns different?
• How are mosses and ferns alike?
Quiz Time
• How are Tracheophytes different from
bryophytes?
• How are tracheophytes divided?
• What are the advantages of seeds over spores?
• What other advantages did seed-bearing plants
have over spore-bearing plants?
• What are the two divisions of the seed-bearing
tracheophytes?
Quiz Time
•
•
•
•
•
•
What does the term Gymnosperm mean?
What are the most common of the Gymnosperms?
What is the evolutionary importance of needles?
What structures do conifers use to reproduce?
Were are seeds located in the cone?
Even though wind-dispersal of pollen is inefficient,
what did it allow plants to overcome?