Plant Diversity

The Evolution and Classification of

Plants

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What do I know about plants?

True or False1. All plants perform photosynthesis.

2. All plants need water and nutrients.

3. All plants reproduce using flowers.

4. All plants reproduce using seeds.

Warm-up: Write each Question and Answer for Each.

PLANT CHARACTERISTICS

• Multicellular

• Eukaryototic

• Autotrophic

• Non-mobile (fixed to one spot)

• Cell walls made of cellulose

• Responds to environment

• Grows through the use of hormones

Slide # 3

The ancestors of plants were:

multicellular green algae.

1. How to transport resources within the plant.

2. How to prevent from drying out

3. How to reproduce without water

Plants Make the Move to LandSlide # 4

Problems to solve:

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 # 5

Plants are classified based on whether or not they have

1. Vascular System (transport)

2. Seeds

3. Flowers (for reproduction)

Slide # 6

Concept Map: Plants are divided 1st by whether or not they have a vascular system.

Bryophytes Tracheophytes

Plants

Vascular TissueNO Vasc Tissue

Slide # 7

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 # 8

Typical Moss Plant (most common bryophyte)

Spores form inside the capsule.

Slide # 9

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 # 10

Tracheophytes are divided into two groups by whether or not they reproduce with seeds.

Tracheophytes

Seedless Seeded

Ferns use spores

Slide # 11

1. Vascular system.

2. Has stems, roots,

3. Reproduce using spores.

The Fern - a seedless vascular plant

There are 11,000 species of ferns.

Slide # 12

Tracheophytes

Seedless Seeded

Ferns use spores

Gymnosperms Angiosperms

“naked” or exposed

seeds

Flowers produce fruit w/ enclosed

seeds

• Cycad (Sago palm), • Ginkgo, • Conifer (pine, spruce, firs, cedars, sequoias, redwoods,

junipers, yews, & cypress trees)

Gymnosperms- “naked seed”

Sago Palm Ginkgo Ginkgo

Slide # 15

Conifers have needles for leaves • have a reduced surface area • thick waxy coat on the needle to

reduce water loss and prevent freezing.

Gymnosperms-ConifersSequoia

JuniperPine

Slide # 16

Conifer Reproduction

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

Pollen Cone

Seed Cone

Slide # 17

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.

Slide # 18

From flower to seedling:

• 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 size-

wise?• 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?