evolution of plants chapter ch 21 pp. 559-562 pp. 564 chap 22: pp. 577-579; pp. 581; 584-587;...

Evolution of PlantsChapter Ch 21 pp. 559-562

pp. 564

Chap 22: pp. 577-579; pp. 581; 584-587; 588-590; 594-597.

Characteristics Of all Plants

1. Cell walls of cellulose

2. Cuticle: Waxy, waterproof coating; avoid drying up.

4. Reproduce by Spores & seeds

5. Alternation of Generations

I. Evolution of Plants

Evolved from Algae-chlorophyta

Adaptations to Dry Land:

Overcame 3 Challenges:Overcame 3 Challenges:1. Avoid Drying Out1. Avoid Drying Out2. Obtain Minerals (nutrients) and 2. Obtain Minerals (nutrients) and

Water from Rocky SurfacesWater from Rocky Surfaces3. Reproduce on Land3. Reproduce on Land

Challenge #1Cuticle

Waxy, waterproof coating on leaves & stems

avoid drying up

Challenge #2: Distribute water & Nutrients.

Most have Vascular Tissue These are called Vascular Plants

Vessels transport Water and NutrientsEnables Plants to Grow LARGE

Challenge #2 --More

Non-vascular plantsMossNo Vascular tissue

Live in moist environmentsTransport water & nutrients by Osmosis & diffusion

Challenge #3-Reproduce On Land---Spores and Seeds

Reproductive StructuresReproductive Structures Resist Resist Drying.Drying. 1.Spores: Tiny; Wind Carried

Produced by All Nonvascular Plants and some vascular Plants (the ferns)

2. Seeds: Produced by Vascular Plants: Plant embryo surrounded by protective coat.

Alternation of Generations:

• Two Forms during plant life cycle:

• Haploid Gametophyte Stage alternates with a Diploid

Sporophyte Stage

II. Types of Plants1.Nonvascular-Bryophytes (mosses)

2.VascularA)Spore-Bearing---FernsB) Seed bearing

1) Gymnosperms-”Naked” Seeds2) Angiosperms-Seeds in Fruits

Nonvascular PlantsMosses (most widespread)

Liverworts, Hornworts

Nonvascular Plants-Characteristics

1. The First Successful Land Plants

2. Small (most under 1 inch tall)

3. No vascular Tissues.

More Non Vascular Plant Characteristics

4. Need Lots of Water:

Habitat: moist; swampy; shorelinesDiffusion & Osmosis: Obtain water &

Nutrients For reproduction-sperm swim to egg.

5. Rhizoids-Primitive Root-Anchorlike & absorptive6.Cuticle on upper surface only

7. Gametophyte is dominant –green, leafy

Reproduction in Mosses1.Gametes form at tips of Green, Leafy Gametophyte (what we usually see).

2. Sperm swim to egg (need film of water).

(fertilization zygote)

3.Moss Sporophyte grows from this Zygote

(bare stalk with a spore capsule on top; here haploid spores form; nutrients obtained from the gametophyte it is growing on top of)

4. Capsule opens; wind carries spores.

5. Spores grow into new Gametophyte.

III. Evolution of Vascular Plants—Ferns, shrubs, trees

Vascular Tissuea) Xylem: water and minerals from roots

upb) Phloem: sugar from leaves to all tissuesEarliest Used Spores Instead of Seeds (Ferns)Sporophyte is Dominant

Ferns: Seedless Vascular Plant Reproduce by spores—no seeds—

Continued

3. Gametophyte produces gametes.

4. Water carries sperm to egg, they fuse (Fertilization) to form diploid Sporophyte Form.

Cycle continues.

Vascular Plants:Seed Plants Adaptation to dry

environments.A)Vascular tissue-carry

water & nutrientsB)Reproduce without

water; PollenC) Seeds-protect

embryo

2 Divisions: Gymnosperms (cones) & Angiosperms (flowers & fruits)

SEEDS-Survive unfavorable Conditions

1.House the plant Embryo.

2. Hard outer Seed Coat-protects embryo.

3. Contain stored nutrients.Endosperm: food for embryoCotyledon- surrounds embryo of flowering

plant-first leaves .Cotyledon Stores food or helps absorb food stored elsewhere.

…More on Seeds4. Help carry plants distance from parents:wind & animalsHooks, feathery or winglike structures

Seeds5. May remain dormant.

6. Upon favorable conditions, seed Germinates (cracks open & starts to grow) into a Seedling.

Seed Plants-2 types1.GymnospermsHave ____________

2.Angiosperms: have___

Types of Seed Plants #1. Gymnosperms- “Naked

Seeds”

Seeds Form in Cones.

Vascular Plants With Seeds-

#2. Angiosperms1. Flowers and Fruits

2.Majority of Vascular plants.

Seeds formed in flowers and enclosed in Fruits.

Angiosperms-Flowers:Help ensure pollination:

Colors, shapes, fragranceAttract particular insects, birds, etc.

Fruit Protects seeds

Helps disperse seeds

ACTIVITYVascular or Non vascular Plant?Spore or Seed Bearing?Dominant Stage/Generation?Label the: GametophyteSporophyte

Describe the process of reproduction in this plant?

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imation.