I. Characteristics of Plants- appeared 500 million years ago from algae
- A. Eukaryotic
- B. Multicellular
- C. Autotrophic
- (Photosynthetic)
- D. Cell walls made of cellulouse
- E. Organs
-roots, stems, leaves
- F. Adaptations for land
1. Waxy cuticle prevents dessication (drying out)
2. Leaves- Broad, flat organs
- Major site of photosynthesis
- Trap light
3. Roots- organs for absorbing nutrients and water
- Anchor plant
- Transport nutrients
- Store starch
4. Stem- Structure for overcoming gravity
a. Vascular- Transport water, nutrients, and carbohydrates
b. Nonvascular- No specialized tissues for small cells, transport, and diffusion
5. Seed- Embryo and food supply
- Protective coat
- Transport and prevent drying
6. Alternation of generations
a. dominant generation- whatever (spore or gamete)
- most conspicous and is the largest plant
- II. Seedless plants
- A. Nonvascular
- Produce spores, but not seeds
1. Liverworts
- Division Hepatophyta- moist places
2. Hornworts
- Division Anthocerophyta
- Small, moist, shady places
3. mosses
- Division Bryophyta
a. Dominant generation- Gametophyte
b. Sphagnum- peet moss, bogs, fuel, absorbs H2O
c. Rhizoids- root like structures anchor the plant
- B. Vascular- xylemophloem, vascular tissues (seedless)
- 1. Whisk ferns- Psilophyta (no roots or leaves)
- Photosynthesis in stems, 2 genera
- 2. Club mosses
- Lycophytes- stems, roots, and leaves
- 3. Horestails
- Spherophyta- hollow, jointed, photosynthesis in stems
- 4. Ferns
- Pterophyta- largest group
a. Dominant generation- Sporophyte
b. Roots, stems, and leaves
c. Rhizome
- underground stems, asexual reproduction
d. Sori
- structures where meiosis occurs to produce spores
- III. Seed Plants
- A. What is a seed?
-Plant embryo
-Food Supply (endosperm)
-Protective coat
- B. Ginkophyta - Ginkgo biloba
-Herb w/ memory and energy
-Seeds have fleshy coat
-Female and male are on different plants
- C. Coniferophyta
1. Gymnosperm- Naked seed
2. Evergreen (mostly)- Don't shed leaves yearly
3. Pine needles- resin- keeps insects away (bitter)
- prevents water loss
- D. Anthophyta- Flowering plants
1. Angiosperm- covered seeds (fleshy sugar water covering)
2. Fruit- Dry Vs. Fleshy- ripened fleshy ovary of the flower
3. Monocots- 1 seed leaf (cotyledon), fibrous roots, 3x flower parts, parallel veins
4. Dicots- 2 seec leaves, 4x or 5x flower parts, branced veins, taproot
5. Life span- Annuals- 1 year, Biannials- 2 years, Parentials- live many years
6. Life cycle
a. female gametophyte- Embryo Sac, multicellular, gametophyte
b. male gametophyte
c. pollination
d. fertilization- Tube cell grow pollen tube, double fertilization
e. seed and fruit formation- wall of ovary
f. seed dispersal- animals, wind, water
g. seed germination
dormancy- inactive state
radicle- embryonic root
monocot- push 1 leaf up through the soil
dicot- pull 2 leaves behind the seed
