Kingdom: Plants Domain Eukarya 2007-2008 Domain Bacteria Archaea Common ancestor 2007-2008

Let’s see where we’ve been: To begin, copy this diagram in your notes.

The first plants For more than 3 billion years, Earth’s terrestrial surface was lifeless life evolved in the oceans 1st photosynthetic eukaryotes were aquatic green algae Chlamydomonas

Present day relatives to ancient plants Chara (charophytes Coelochaete Protists: all live in what kind of enviroment? Spirogyra Volvox

Evolution of Land Plants 500 mya land plants evolved -- why-- special adaptations for life on dry land protection from drying = desiccation waxy cuticle gas exchange (through cuticle) stomates water & nutrient conducting systems xylem & phloem protection for embryo seeds

Plant Diversity Bryophytes non-vascular land plants Pteridophytes seedless vascular plants Gymnosperm pollen & “naked” seeds Angiosperm flowers & fruit conifers flowering plants mosses ferns seed plants vascular plants colonization of land

Animal vs. Plant life cycle Animals are Plants are diploid multicellular 2n diploid multicellular sporophytes 2n Meiosis produces mitosis Meiosis produces fertilization Gametes n Used for? Spores, n. Grow by Fertilization Development by: Mitosis produces unicellular gametes, n. Used for? Into multicellular Gametophyte n mitosis Draw this circle: alternation of generations!

The first land plants were… Bryophytes: mosses, horn- & liverworts non-vascular no water transport system no true roots flagellated swimming sperm lifecycle dominated by haploid gametophyte stage haploid diploid Where must mosses live?

fuzzy moss plant you are familiar with is haploid spores for reproduction haploid cells which sprout to form gametophyte ‘n’ By meiosis! ‘2n’ By mitosis!

Bryophytes: mosses & liverworts

“Peat Moss” Peat Bog

First vascular plants Pteridophytes: ferns vascular swimming sperm Diploid sporophyte First vascular plants Pteridophytes: ferns vascular water transport system xylem, phloem, roots, leaves swimming sperm flagellated sperm Where must ferns live? Haploid sporangia

Common ferns are diploid sporophytes, produce spores by meiosis Common ferns are diploid sporophytes, produce spores by meiosis. These grow up to be Gametophytes; inconspicuous Antheridia, archegonia produce gametes

Pteridophytes: Ferns, horsetails, club mosses Selaginella Psilotum Ground pine (club moss) Ferns

& now, a little review… Where are the sporangia located on ferns? Which generation is dominant in bryophytes? Pteridophytes? What produces male gametes in seedless plants? Female gametes? OK GOOD! Let’s move on.

The Fern gametophyte (n) The alternate generation Small, haploid, produces gametes homospory: male & female on same plant archegonia antheridia

Early Pteridophytes: Tree Ferns With fronds like these who needs enemies! Fossil fuels… I get it! Carboniferous forest – 290-350 mya Forests of seedless plants decayed into deposits of coal & oil

Ch 30

Gymnosperms: conifers Vascular, heterospory First seed plants Gymnosperms: conifers Vascular, heterospory Male, female gametophytes separate seeds naked (no fruit) pollen contains male gametophyte

Familiar conifers are diploid sporophytes gametophyte is greatly reduced, microscopic. Reduction protects delicate egg & embryo within protective sporophyte tissues protected from drought, UV radiation

Odd but interesting Gymnosperm: ginkgo (G Bilboa) Smell like feces Flagellated sperm

Early Gymnosperm: cycads

Gymnosperm: conifers

male female sporangium & pollen male (pollen) cones female cones pine embryo

Pollen = male gametophyte Pollen eliminated the need for water for fertilization spread through wind & by animals Whose got allergies?

Angiosperms: flowering plants sporophyte dominant Vascular, seed bearing Flowering Heterosporous; pollen, ovules 2 spore types develop in 2 locations seeds enclosed in fruit Grasses, flowers,trees & shrubs are are diploid Sporophytes with Microscopic gametophytes

Angiosperm: flowering plants

Angiosperm life cycle male gametophyte in pollen (haploid) Polar nuclei Angiosperm life cycle Pollen grains male gametophyte in pollen (haploid) Egg cell fertilization female gametophyte in ovary (haploid) sporophyte in seed (diploid)

The male angiosperm gametophyte

Flower Modified shoot with 4 rings of modified leaves sepals petals stamens male carpel female Anther Filament Stamen Stigma Style Ovary Carpel Sepal Petal Ovule sepals petals stamens carpel

Co-evolution: flowers & pollinators How a bee sees a flower…insects see UV light = a bulls-eye to the nectar

Angiosperm: fruiting plants

Other fruits…

Seeds result from double fertilization, in angio’s Seed & Plant embryo seed coat Seed offers… protection for embryo stored nutrients for growth of embryo endosperm cotyledons embryo Seeds result from double fertilization, in angio’s cotyledons = “seed” leaves, first leaves of new plant

Monocots & dicots Angiosperm are divide into 2 classes dicots (eudicot) 2 cotyledons (seed leaves) leaves with network of veins woody plants, trees, shrubs, beans monocots 1 cotyledon leaves with parallel veins grasses, palms, lilies

Any Questions?? 2007-2008