Kingdom Plantae

Kingdom Plantae Notes

Importance of Plants

  • Primary Providers of Oxygen

    • Through photosynthesis, plants convert carbon dioxide and water into glucose and oxygen, essential for life.

  • Source of Energy

    • Forests provide fuel and energy; sustainable management is crucial.

  • Food Source

    • Plants are fundamental to the food chain; they are the primary producers.
    • Historical significance:
    • Irish Potato Famine (1845-1852)
      • Potatoes constituted 80% of the typical Irish diet, leading to mass starvation and emigration when the crop failed.

  • Medicine

    • Numerous medicines derive from plant compounds:
    • Atropine (Belladonna): pupil dilator in eye exams.
    • Digitalin (Foxglove): heart medication.
    • Menthol (Eucalyptus): ingredient in cough medicines.
    • Morphine (Opium poppy): pain reliever.
    • Quinine (Quinine tree): malaria preventive.
    • Paclitaxel (Taxol) (Pacific yew): drug for ovarian cancer.
    • Tubocurarine (Curare tree): muscle relaxant during surgery.
    • Vinblastine (Periwinkle): leukemia drug.

  • Material Source

    • Wood, fibers, and other materials used in construction, textiles, and goods.

  • Environmental Benefits

    • Plants clean the air by absorbing carbon dioxide and releasing oxygen.

Plant Characteristics & Adaptations

  • Significant Properties of Plant Cells:

    • Chloroplasts: site of photosynthesis.
    • Cell Walls: provide structure and protection.
    • Plasmodesmata: channels allowing communication between plant cells.
    • Central Vacuoles: storage and maintaining turgor pressure in cells.

  • Adaptations for Land:

    • Cuticle: reduces water loss.
    • Stomata: regulates gas exchange.
    • Support Structures: stems and root systems provide physical support and nutrient uptake.

  • Plant Tissue Culture:

    • Explains totipotency in plant cells; a single cell can regenerate into a complete plant. Steps include:
    1. Take tissue sample from parent plant.
    2. Place in agar growth medium.
    3. Develop plantlets.
    4. Transplant to nutrients-rich compost.

  • Modified Roots and Stems:

    • Examples include:
    • Rhizomes: underground stems that store energy (e.g., ginger).
    • Tubers: swollen underground stems (e.g., potatoes).
    • Storage Roots: modify roots for nutrient storage (e.g., carrots).

Types of Plants

  • Four Major Groups of Plants:

    • Bryophytes: non-vascular (mosses)
    • Ferns: vascular, spore-producing
    • Gymnosperms: seed-producing without flowers (e.g., conifers)
    • Angiosperms: flowering plants with seeds.

  • Seed Dispersal Mechanisms:

    • Essential for plant reproduction; methods include wind, water, and animal assistance.

Flowering Plants: Monocots vs. Eudicots

  • Distinguishing Features of Monocots:

    • One seed leaf (cotyledon); parallel leaf venation; scattered vascular bundles; flower parts in multiples of three.

  • Distinguishing Features of Eudicots:

    • Two seed leaves (cotyledons); net-like leaf venation; vascular bundles in a ring; flower parts in multiples of four or five.