bio plant quiz pt.2

Plant Evolution & Characteristics

  • Evolution of Land Plants: Adapted from green algae. Major steps include vascular tissue, seeds, pollen, flowers, and fruits.

  • Defining Plant Traits: Photosynthesis, cell walls made of cellulose, alternation of generations.

  • Other Photosynthetic Organisms (Not Plants):

    • Purple bacteria (photosynthesis w/o oxygen)

    • Chromera velia (protist w/ plastid)

    • Trebouxia (algae in lichens)

Importance of Plant Features

  • Cell Walls: Made of cellulose; provide structure and prevent water loss.

  • Embryophytes: Protect embryos in parent plant; key for land survival.

  • Alternation of Generations: Switch between gametophyte and sporophyte; increases diversity.

  • Photosynthesis: Converts sunlight, water, and CO₂ into sugars; releases oxygen.

4 Divisions of Plants

  1. Bryophytes: No vascular tissue, need water to reproduce (e.g., moss, liverwort)

  2. Pteridophytes: Vascular, reproduce with spores (e.g., ferns, horsetails)

  3. Gymnosperms: Naked seeds, cones (e.g., pine, cycad)

  4. Angiosperms: Covered seeds, flowers & fruits (e.g., sunflower, oak)

Labeled Diagrams & Plant Examples

  • Moss (Bryophyte): Non-vascular, reproduces via spores.

  • Gymnosperms: Ginkgo biloba, white cedar, hemlock.

  • Angiosperms: Silver maple, pin oak, andromeda.

Comparison Charts

  • Bryophytes vs. Ferns: Differences in vascular tissue, reproduction, habitats.

  • Angiosperms vs. Gymnosperms: Covered vs. naked seeds, environments, pollination methods, life cycles.

Plant Evolution & Adaptations

  • Ancestry: Plants evolved from green algae.

  • Key adaptations for land:

    • Leaves with stomata (gas exchange)

    • Roots (absorb water)

    • Vascular tissue (xylem & phloem for transport)

    • Seeds (protect and nourish embryo)

    • Flowers (aid in fertilization)

🌿 Major Plant Groups

  1. Bryophytes (mosses, liverworts):

    • First land plants

    • No vascular tissue, roots, or seeds

    • Need water to reproduce

    • Gametophyte dominant

    • Found in wet, shady habitats

  2. Pteridophytes (ferns, horsetails):

    • Vascular tissue present

    • Reproduce via spores

    • Sporophyte dominant

  3. Gymnosperms (pines, firs, cedars):

    • "Naked seeds" in cones

    • No flowers or fruit

    • Needle-like leaves with stomata & resin canals

    • Adapted for cold or dry climates

    • Wind pollinated

  4. Angiosperms (flowering plants):

    • Seeds enclosed in fruit (develop from ovary)

    • Have flowers for pollination

    • Can be pollinated by animals or wind

    • Most diverse plant group

    • Have vascular tissues and meristem layers

    • Can reproduce sexually or asexually

🌻 Angiosperm Reproduction

  • Sexual:

    • Wind-pollinated: Light pollen, causes allergies

    • Animal-pollinated: Sticky pollen, targeted delivery

  • Asexual (vegetative):

    • Strawberries (runners)

    • Bamboo (underground stems)

    • Potato tubers

    • "Mother of Thousands"

🌾 Seed and Fruit Differences

  • Gymnosperms: Seeds exposed on cone scales

  • Angiosperms: Seeds develop inside fruit (ovary wall)

    • Seed contains: embryo, food supply, protective coat

🍂 Plant Life Cycle Categories

  • Annuals: Complete life cycle in 1 year (e.g., sunflower, rice)

  • Biennials: 2 years (1st = growth, 2nd = flower, e.g., mullein)

  • Perennials: Live 3+ years (e.g., oaks, shrubs)

🌍 Bogs and Ecology (Bryophytes)

  • Sphagnum moss forms peat bogs

  • Stores CO₂; slows decomposition

  • Vital for boreal ecosystems and climate stability

  • Peatland thawing = greenhouse gas release (CO₂, methane)