Plant Diversity

1
Plant Diversity
The Evolution and Classification of Plants
2
Slide 2
Warm-up Answer for Each
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.

3
PLANT CHARACTERISTICS
Slide 3

1. Multicellular eukaryotes
2. Photosynthetic autotrophs containing
   chloroplasts.
3. Non-motile (fixed to one spot)
4. Cell walls made of cellulose
5. Respond to environment and grow by using hormones

4
What Plants Need to Survive
Slide 4

1. Sunlight
2. Gas exchange - System for taking in CO2 and
   releasing O2
3. Water
4. Minerals

All are needed so that plants can carry out
photosynthesis!
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Slide 5
Cladogram of Kingdom Plantae
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Slide 6
Problems with Living on 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
• How to get chemical resources (water, minerals,
  oxygen, and carbon dioxide) separated into air
  and soil
• How to transport resources within the plant.
• How to keep from drying out
• How to reproduce without water

7
Slide 7

• SOLUTIONS (ADAPTATIONS)
• Leaves (CO2) and roots (H2O)
• Develop a vascular system to transport resources
  in plant
• Have a protective layer cuticle (waxy outer
  layer) to keep from drying out
• Specialized structures for reproduction including
  spores seeds that do not dry out

8
Vascular Tissue
Slide 8

• 1. Vascular Tissue- hollow tube-like cells that
  transports materials throughout the plant
• Xylem- transports H20 up from roots.
• Phloem- transports food made in photosynthesis
  to where it is needed in the plant.

Xylem (water) Phloem (food)
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Bryophytes - NONVASCULAR
Slide 9

1. Live in moist, shady areas
2. NO vascular (transport) system
3. Small size because no vascular tissue
4. No true roots, stems, or leaves
5. Need water for reproduction.
6. Reproduces using spores, -asexual cell that can
   grow into a new organism.
7. Examples Moss, Liverworts, Hornworts

moss
liverworts
hornworts
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Slide 10
Ferns - Seedless Vascular Plants

1. Have vascular tissue.
2. Have true roots, stems leaves
3. They grow in moist, shady habitats.
4. Have underground stems, roots, large leaves
   called fronds.
5. Reproduce using spores, NOT seeds.

There are 11,000 species of ferns.
Sori
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Seed Plants
Slide 11

• ADVANTAGE reproduction IS NOT dependent on
  water
• Seed contains
• A fully developed embryo
• Food supply for embryo
• A water-proof seed coat to keep from drying out
• Sperm transferred in water-proof pollen through
  pollination by wind or animals.
• Developed seed-bearing structures Cones Flowers

embryo
endosperm
Seed coat
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Gymnosperms- naked seed
Slide 12

• 1. Cycad (Sago palm),
• 2. Ginkgo,
• 3. Conifer (pine, spruce, firs, cedars,
  sequoias, redwoods, junipers, yews, cypress
  trees)

Sago Palm
Ginkgo
Ginkgo
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Gymnosperms-Conifers
Sequoia
Slide 13

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.

Juniper
Pine
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Conifer Reproduction
Slide 14
Slide 14

• 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
Seed Cone
Pollen Cone
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Angiosperms- enclosed seeds
Slide 15

• 1. Flowering plants that 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.

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Two Divisions of Angiosperms Monocots and
Dicots
Slide 16