Survival of Plants:

• Need sunlight (energy for photosynthesis)

• Water

• Minerals/Nutrients

  • Phosphorous

  • Potassium

  • Magnesium

  • Calcium

  • Nitrogen

• Gas exchange with environment

• Movement of water and nutrients from roots to leaves

• Diffusion

• Specialized tissues

Early Plants:

• Origins in the water (algae)

• First plants evolved from plant-like protists (algae) similar to multicellular green algae of today (chlorophyta)

• Oldest known plant fossil: 450 mya

• Similar to mosses of today

4 Divisions

• Mosses

• Ferns

• Conebearers

• Flowering plants

Byrophytes (Parent Group):

• These are Mosses and Relatives

• Nonvascular

  • They depend on osmosis to deliver water; this keeps them small

• Groups:

  • Mosses: most common

    • tolerant in harsh environments

  • Liverworts: “flat leaves”

    • attached to the ground

  • Hornworts: Phylum: Anthrocerophyta

• Life Cycle:

  • It is dependent on water because sperm of bryophyte must swim to an egg

  • NO SEEDS

• Human Uses:

  • Sphagnum:

    • Accumulates in peat deposits

    • Retains water

Vascular Tissue: transportation system that allows for the movement of fluids against gravity

Two types:

• Xylem: carries water up

• Phloem: carries nutrients and carbohydrates down

Ferns and Relatives (Vascular):

• Club Mosses

• Horsetails

• Ferns

They all have true:

• Roots: underground organs used for absorption

• Leaves: photosynthetic organs

• Veins: gathering of xylem and phloem

• Stems: supporting and connecting structures

Life Cycle:

• Develop haploid spores on undersides of fronds called Sporangia

• Grouped in clusters of sori

• Fertilization requires at least a small film of water

Seed Plants:

• Gymnosperms

• Angiosperms

• These are the most successful plants

• Adaptations:

  • Allows for reproduction without water

  • Includes flowers and cones

  • Pollination transfers sperm

  • Embryos are protected in seeds

• Pollen grain: where entire male gametophyte is contained

• Sperm do not swim

• These are carried to female reproductive structure through: insects, wind, or small animals

• Seed: embryo of plant

Gymnosperms (Cone Bearers) :

• Most ancient seed bearer

• Gymnosperms Includes:

  • Gnetophytes, Cycads, Ginkgoes, Conifers

• Gnetophytes:

  • Phylum: Gnetophyta

    • Only 70 species

• Cycads:

  • Phylum: Cycadophyta

  • Palm-like plants

    • Only 9 genera exist today

• Ginkgoes:

  • Phylum: Gingkophyta

• Conifers:

  • Phylum: Coniferophyta

  • Most common gymnosperm

  • 500 species

  • Pines, spruces, redwoods, sequoias, cedars

    • Ecology of Conifers:

      • Wide variety of habitats

      • Evergreens

      • Have adaptations such as needle shaped leaves and waxy covering to protect from dry conditions

Angiosperms (Flowering Plants) :

• Flowers: unique reproductive structures

• Pollination through animals is more effective than wind pollination

• Flowers contain ovaries, which surround and protect the seed

• After pollination, ovary develops into a fruit (wall of tissue surrounding the seed)

• Two classes of Angiosperms:

  • Named for the number of leaves (cotyledons) in plant embryo

  • Monocots: one seed leaf

    • Corn, wheat, lilies, orchids, palms

  • Dicots: two seed leaves

    • Roses, clover, tomatoes, oak, daisies

Groups By Stems:

• Woody: have thick cells

  • Trees, shrubs, vines

• Herbaceous: do not produce woody stems

  • Sunflowers, pansies, etc