i. terrestrial invasion a. mineral absorption 1. n k s ca p mg
TRANSCRIPT
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