I. Terrestrial InvasionA. Mineral absorption

1. N K S Ca P Mg

I. Terrestrial InvasionA. Mineral absorption

1. N K S Ca P Mg 2. mycorrhizae

I. Terrestrial InvasionA. Mineral absorption

1. N K S Ca P Mg 2. mycorrhizae

B. Water conservation1. waxy cuticle (on exposed areas)

- prevents water loss- water enters at roots

I. Terrestrial InvasionA. Mineral absorption

1. N K S Ca P Mg 2. mycorrhizae

B. Water conservation1. waxy cuticle (on exposed areas)

- prevents water loss- water enters at roots

2. stomataa. passages in the cuticleb. allow gas exchangec. water vapor

C. Reproducing1. plants are immobile

- creates problem for sexual reproduction

- pollen- how can sperm get from one plant to another?

2. sporesa. a cell that can develop into another organism without fusing with another cellb. basically asexualc. resist drying

D. Structural support1. gravity vs. water

2. lignin: chemical that strengthens plant cell walls

E. Life cycle changes1. alternation of generations

- diploid alternates with haploid

2. sporophytes (diploid generation)- form haploid spores my meiosis- sporophyte grows by mitosis- most vascular plants

3. gametophytes (haploid generation)- form haploid gametes by mitosis

3. gametophytes (haploid generation)- form haploid gametes by mitosis- fused gametes (fertilization) form the sporophyte

F. Vascular system (found in 9 of 12 plant phyla)1. roots and shoots

2. tall plants need good plumbing (vascular systems)- vascular plants- highly successful (>250,000 species)

G. Avascular plants (bryophytes)1. first land plants

- still the simplest2. lack lignin

- still have some conducting tubes- limited size

3. liverworts, hornworts, mosses4. still have flagellated sperm

Liverwort

Sphagnum Moss

Thalloid Liverwort

Hornwort

II. Vascular PlantsA. Features

1. dominant sporophyte2. specialized conducting tissues

- reinforced cell walls (lignin)- vascular bundles

3. specialized body form- roots, stems, leaves

B. Conducting systems1. phloem

- living cells- transports carbohydrates

B. Conducting systems1. phloem

- living cells- transports carbohydrates

B. Conducting systems1. phloem

- living cells- transports carbohydrates

2. xylema. hard-walled cells

- deadb. transport water and minerals

Vascular Bundles

G. Growth 1. indeterminate

- most plants- growth for duration of life span

2. determinate- most animals- growth until a certain size is reached

3. primarya. cell division at tips of roots and stemsb. from apical meristemsc. taller but not wider

4. secondarya. new cells laid around peripheryb. increased diameter

- allows increase in heightc. from lateral meristems (2 of them)

- vascular cambium- cork cambium

d. wood- secondary xylem- lignin provides the rigidity

d. wood- secondary xylem- lignin provides the rigidity

e. rings- vary in size according to amount of growth each season

D. Seedless varieties1. dominated the Carboniferous period (360-299 MYA)

- coal

D. Seedless varieties1. dominated the Carboniferous period (360-299 MYA)

- coal2. water required for fertilization

- sperm must swim

3. ferns (most abundant)a. independent sporophyte (diploid) and gametophyte (haploid) formsb. gametes from gametophyte unite zygote

c. zygote develops into sporophyte (diploid)- produces haploid spores- spores released

d. spores develop into gametophyte (haploid)e. fern gametophyte: small, thin, photosynthetic, heart-shapedf. fern sporophyte

- large, complex- fronds