Plant Kingdom Summary

Kingdom Plantae Characteristics

  • Eukaryotic cells with membrane-bound organelles

  • Cell walls composed of cellulose

  • Autotrophic nutrition through photosynthesis

  • Presence of chlorophyll A and B, xanthophylls, carotenoids

  • Starch as the storage carbohydrate

  • Development from an embryo

  • Alternation of generations in life cycle

  • Mostly terrestrial plants (e.g., epiphytes, parasitic plants, carnivorous plants)

Plant Life Cycles

  • Show alternation of generations

  • Diploid sporophyte produces haploid spores via meiosis

  • Spores develop into haploid gametophytes which then produce gametes

  • Fertilization restores diploid state

Adaptations for Life on Land

  • Obtaining, conserving, transporting water

  • Support for upright growth (lignin structure)

  • Protective structures (cuticles, stomata)

  • Young sporophyte develops inside female gametophyte

Evolutionary Trends in Plantae

  • Progression from simple to complex organisms

  • Non-vascular (like mosses) to vascular plants (like ferns, conifers, flowering plants)

  • Shift from motile to non-motile gametes

  • Transition from haploid dominance to diploid dominance

  • Development of seeds

Key Plant Phyla

Bryophyta (Mosses and Liverworts)

  • Simple structure, no cuticle, non-vascular

  • Gametophyte is dominant

  • Indicators of environmental conditions

Pterophyta (Ferns)

  • Vascular with roots, stems, and leaves

  • Diploid dominance; need water for reproduction

  • Often grow in shaded environments

Coniferophyta (Conifers)

  • Cone-bearing, with unprotected seeds

  • Vascular system and adapted for water loss prevention

  • Wind-pollinated, diploid dominated

Anthophyta (Flowering Plants)

  • Diverse size range, complex reproductive structures

  • Pollination strategies involving various animal species

  • Sexual and asexual reproduction

Reproductive Strategies

  • Sexual: Flowers produce spores (microspores and megaspores)

  • Asexual: Vegetative reproduction via stolons, rhizomes, tissue culture

Seed Development

  • Eudicots: Store nutrients in cotyledons, include processes like double fertilization.

  • Monocots: Cotyledon absorbs nutrients, with protective structures for seedlings.

Fruit Types and Seed Dispersal

  • Simple vs. compound fruits, methods of dispersal involve animals, wind, and mechanical mechanisms.

  • Environmental conditions necessary for seed germination include warmth, moisture, and oxygen.