Chapter 21: The Plant Kingdom

Key Features of Plants: Chapter 21: Plant Kingdom Key Features of Plants: Multi-cellular / Photosynthetic: Cell wall composed of cellulose Chloroplast: Converts light energy to food (chlorophyll) Sessile: Stationary in one spot throughout life Complex life cycle...

Chapter 21: Plant Kingdom Most distinctive feature The Sex Life of Plants... Plants can reproduce either sexually or asexually Asexual: Single plant  new plant (genetically identical) Daffodil bulbs; Strawberry runners Sexual: Parental plants  new plant (genetic mix) Most plants Plant sexual life history is complex: Alternation of Generations: Diploid (2n) plants alternate with haploid (1n) plants Diploid = 2 sets of chromosomes Haploid = 1 set of chromosomes

Alternation of Generations: 1) Diploid adult (sporophyte - (2n)) 2) Haploid adult (gametophyte - (1n)) Produce spores (meiosis - (1n)) Spores germinate Produce gametes (mitosis - (1n)) Gametes Join (Zygote - 2n) (Figure 21.1)

Chapter 21: Plant Kingdom Alternation of Generations

Function of Plants in Biosphere: Chapter 21: Plant Kingdom Function of Plants in Biosphere: Primary producers (via photosynthesis) Help maintain aerobic (oxygenated) environment Provide medicines (bio-prospecting) Foxglove Digitalis (heart) Nightshade Atropine (heart) Yew Tree Taxol (cancer) Willow Aspirin (pain)

Green Algae Probably Gave Rise to Land Plants (evolutionary origin): Chapter 21: Plant Kingdom Green Algae Probably Gave Rise to Land Plants (evolutionary origin): Include single / multi-cellular forms Primarily inhabit freshwater Form symbiotic relationship with fungi Green Algae: Support for Hypothesis: 1) Both use same type of chlorophyll for photosynthesis 2) Both store food as starch (carbohydrate) 3) Both exhibit cell wall composed of cellulose Above adaptations allowed for green algae to survive in freshwater environment (extreme temperature / water level shifts)

Non-Reproductive Adaptations for Dry Land (most plants): Chapter 21: Plant Kingdom Non-Reproductive Adaptations for Dry Land (most plants): 1) Roots: anchor plant & absorb water / nutrients 2) Cuticle: waxy surface that prevents water loss 3) Stomata: pores that regulate gas exchange & evaporation Non-Reproductive Adaptations for Dry Land (some plants): 4) Veins: conducting system for nutrients & water 5) Lignin: stiffening substance that allows plant to grow upright Reproductive Adaptations for Dry Land (varied): 1) Gamete / Zygote dispersal methods independent of water 2) Structures that protect developing embryos from drying out

Chapter 21: Plant Kingdom (Figure 7.2) (Figure 23.1)

Chapter 21: Plant Kingdom

Gametophytic (1n) stage Chapter 21: Plant Kingdom Plant Groups: 1) Nonvascular Plants (Bryophytes - Mosses & Liverworts) Lack true roots / leaves / stems Rhizoid: Root-like anchoring structure Lack vascular system / lignin (body size limited) Enclosed reproductive structures Gametophytic (1n) stage much larger than sporophytic (2n) stage Archegonia = eggs antheridia = sperm Need water to meet

Chapter 21: Plant Kingdom

gametophytic (1n) stage A) Seedless Vascular Plants (Club mosses, horsetails, ferns): Chapter 21: Plant Kingdom Plant Groups: 2) Vascular Plants (Tracheophytes): Contain vascular tissue and lignin (exploit vertical space) Dominated prehistoric times (coal) Sporophytic (2n) stage much larger than gametophytic (1n) stage Depend on water for reproduction

2) Vascular Plants (Tracheophytes): Chapter 21: Plant Kingdom Plant Groups: 2) Vascular Plants (Tracheophytes): B) Seed Vascular Plants (Currently Dominant plant) Pollen: Protective structure containing male gametophyte Allow for fertilization without the need for water Seed: Protective structure containing developing embryo Allow for development without reliance on water Gametophyte (1n) stage dependent on sporophyte (2n) stage

2) Vascular Plants (Tracheophytes): cycads, Chapter 21: Plant Kingdom Plant Groups: 2) Vascular Plants (Tracheophytes): B) Seed Vascular Plants (Dominant plant - present) a) Gymnosperms (lack flowers): Ginkos, Ginkgo biloba “Improve your Memory” Giant Sequoias & conifers (evergreens) Conifers are Adapted for cold / dry: retain leaves in winter leaves = needles produce sap (“antifreeze”)

Attract animal pollinators (mutualistic interaction) Plant Groups: Chapter 21: Plant Kingdom Plant Groups: 2) Vascular Plants (Tracheophytes): B) Seed Vascular Plants (Dominant plant - present) b) Angiosperms (flowering plants): Flowers: Structures containing male & female gametophytes Fruits: Seed-bearing structures designed for dispersal Broad leaves: Advantage in warm, wet climates Drop leaves during unfavorable conditions

A) Protists (single-celled eukaryotes) Chapter 21: Systematics The Prokaryotes: 1) Bacteria 2) Archaea Domains 3) Eukarya: A) Protists (single-celled eukaryotes) B) Fungi (multicellular; absorptive digestion) Kingdoms C) Plantae (Multicellular; photosynthsis) D) Animalia (Multicellular; ingestion)