PLANTS

What Are Plants Multicellular Eukaryotes Cell walls- cellulose Develop from multicellular embryos Carry out Photosynthesis using Chlorophyll a and b Include: trees, shrubs, grasses, mosses, ferns

Plant Life Cycle 2 phases-mitosis and meiosis alternate to produce two types of cells sporophyte -Diploid (2n)- spore producing plant Gametophyte- Haploid (n)- gamete producing plant Early plants(mosses/ferns) require water for reprod. Later plants use seeds Can be asexual or vegetative

What Plants Need To Survive Sunlight- energy for photosynthesis Water + Minerals - photosynthesis Gas Exchange- CO₂ for photosynthesis Movement of Water/Nutrients- specialized tissue to move from roots to leaves Xylem phloem

Early Plants 1st plants evolved from – multicellular green algae (protist) Similarities: Photosynthesis Color Reproductive cycle Cell walls Pigments= chlorophyll DNA sequences

First Plants Mosses

Mosses evolve to form vascular plants Vascular tissue- conduct water/nutrient through plant Ferns Cone bearing plants (conifers) Flowering plants(Angiosperms)

Classification of Plants Based on Water conducting tissues Seeds Flowers

Bryophyta Depend on water for reproduction Lack vascular tissue Use osmosis to draw up water ( few cm) Low growing Live in moist/shaded areas Types: Mosses, Liverworts, Hornworts

Mosses Habitat: areas with water Poor soils Harsh environments Rhizoids-long thin cells, anchor to ground, absorb water

Liverworts Reproduce: sexually/asexually Asexually- Gemmae- multicellular reprod. structures-produced in Gemmae cup

Hornworts Reproductive structure- tiny green horn

Ferns/Relatives Seedless vascular plants Equisetum Club mosses- Lycophyta Horsetails-Equisetum Ferns-pterophyta Depend on water for reprod. Equisetum Lycophyta

Ferns Rhizomes-underground stems Fronds- leaves

Seed Plants Gymnosperms- seeds directly on surface Conifers and ancient palm like plants Angiosperms- flowering plants- bear seeds within layers of tissue

Reproduction- no water Adaptations: Flowers/cones Pollen Protection of embryos in seeds

Cones/flowers- Gametophytes grow and mature in structures

Pollen- male gametophyte carried into female reprod. Structure by wind animal insects

Seed- embryo of plant encased in protective covering surrounded by food supply Seed coat- surrounds/protects contents Prevent drying out

Specialized structure for dispersal Textured to stick Fleshy tissue to be eaten Wind dispersal

Gymnosperms “Naked Seed” Gnetophytes- Africa Cycads- palm-like Ginkgoes-1 species left Conifers

Ecology of Conifers Developed needle shaped leaves with waxy coat to reduce the amount of moisture lost

Angiosperms “Enclosed seed” Unique reproductive structures known as flowers Attract bees, moths, hummingbirds for transport of pollen Contain ovaries- surround and protect seeds-Ovary develops into fruit Fruit-wall of tissue surrounding seed Organisms eat fruit – spread seeds

Monocots/Dicots Fibrous roots Dicots Taproot

Woody/Herbaceous Plants Woody-thick cell walls for support Trees, shrubs, vines Herbaceous-smooth, non-woody Dandelions, zinnias, petunias

Annuals/Biennials/Perennials Life spans Annuals- live one year Biennials- complete life cycle in 2 years Perennials- live for many years

Venus Fly Trap Video