Angiosperms Slides

  • Green plants share ancestry with Charophyceae and contain chlorophyll a+b and \beta-carotene.

  • Categorized into:

    • NONVASCULAR PLANTS: Liverworts, mosses, hornworts.

    • VASCULAR PLANTS:

    • SEEDLESS PLANTS: Ferns, club mosses, whisk ferns, horsetails.

    • SEED PLANTS:

      • Gymnosperms: Ginkgoes, cycads, redwoods, pines, gnetophytes.

      • Angiosperms (flowering plants).

  • Key distinguishing features: Vascular tissue (vascular plants) and Seeds (seed plants).

  • Angiosperms:

    • Appeared around 100\text{ mya}.

    • Approximately 350{,}000 diverse species.

    • Unique features:

    • Flowers enclosing reproductive units.

    • Carpels protecting ovules.

    • Highly reduced female gametophyte (7 cells / 8 nuclei).

    • Double fertilization.

    • Life Cycle:

    • Diploid (2n) sporophyte; Haploid (n) gametophytes.

    • Double fertilization forms a 2n zygote and a 3n endosperm (for embryo nutrition).

    • Advancements:

    • Animal-mediated pollen transport.

    • Fruits (mature ovaries containing seeds) for protection and dispersal.

    • Diverse floral adaptations and pollination strategies.