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.