Angiosperms and Animals

Angiosperms and Animals

  • Pollination:

    • Angiosperms depend on animals to facilitate the pollination of their flowers.

  • Seed Transport:

    • Animals significantly contribute to the dispersal of seeds, which is essential for plant reproduction and the distribution of plant species across various environments.

Deforestation Impact

  • Deforestation in Tropics:

    • Causes the extinction of numerous plant species, disrupting the ecosystem.

  • Loss of Habitat:

    • The reduction in forest areas leads to the decline of animal species dependent on these plants.

  • Extinction Rate:

    • It is estimated that 50% of all Earth's species may face extinction within the next 100 to 200 years if current habitat loss trends continue.

Common Terms for Plants

  • Herbaceous Plants:

    • Characteristics: Do not produce wood.
    • Example: Grasses.

  • Woody Plants:

    • Characteristics: Produce wood and include various forms.
    • Types:
    • Shrubs: Shorter plants with multiple stems.
    • Trees: Taller plants with a single main stem (trunk).

Plant Life Cycles

  • Annuals:

    • Complete their entire life cycle within one growing season (1 year).

  • Biennials:

    • Require two growing seasons to complete their life cycle.
    • First year: Focus on growth.

  • Perennials:

    • Live for many years, often continuing to grow and reproduce year after year.

Plant Structure Types

Types of Plant Organs

  • Plants are built from three types of organs, comprising various tissues and cells:

    1. Stems
    • Function: Supports leaves and reproductive structures.
    • Examples: Stalks, trunks, branches, twigs, rhizomes.
    1. Leaves
    • Function: Specialized for photosynthesis.
    • Structure: Typically consists of two main parts:
      • Petiole: The stem of the leaf that detaches when the leaf falls.
      • Blade: The primary surface for photosynthesis.
    • Additional Components:
      • Node: The site where leaves attach to stems.
      • Internode: The space between nodes.
      • Types of Leaves:
        • Simple Leaves: No additional leaflets.
        • Meristem:
          • A growth site at the base of each petiole, enabling new branches to grow.
          • Apical Meristem: Located at the shoot apex, controlling the growth of axillary buds. When damaged, these buds can start to grow.
    1. Roots
    • Functions:
      • Anchor the plant in soil.
      • Absorb water and nutrients for growth.
      • Store food for future use.
    • Anatomy:
      • Root Cap: Protects the growing tip as it pushes through the soil.
      • Meristem: Located behind the root cap; the site of active growth.
      • Root Hairs: Extensions that increase surface area for enhanced absorption of water and nutrients.

Types of Plant Tissues

  • Each organ is made up of three types of tissues, collectively forming a tissue system:
    • Dermal: Provides an outer protective covering for the plant.
    • Vascular: Responsible for transporting materials (water, nutrients) between the root and shoot systems.
    • Ground: Involved in functions such as storage, photosynthesis, and providing support to the plant.