10/1/2012

BI 103: Plants Taxon: A Ranked Hierarchy Plant Family History Kingdom: Plantae Phylum: Magnoliophyta Class: Magnoliopsida Order: Rosales Family: Rosaceae Genus: Malus Species: Malus pumila

Adaptation to Land Adaptation to Land What types of adaptations are needed to For a Plant: What are the differences between life move from water to land habitat? on land and life in the water? Protection against water loss   Variation in temperature - fluctuation, not Cuticle to prevent water loss, stomata for regulation buffered by water  Variation in moisture - no longer continuously Ability to tolerate variation in temperatures bathed in water Roots for anchoring to substrate and nutrient  Nutrient availability - differences between water absorption and soil and how nutrient uptake occurs Protection for gametes: specialized structures  Gravitational force - floating at the surface was sufficient to get to the sun Gametes (sperm) do not require water  Substrate - differences between water and soil Development of vascular tissue

1 10/1/2012

Bryophytes • Gametophyte generation dominant • true organs lacking • thallus (undifferentiated plant body) • rhizoids (root hair like structures) •unicellular or multicellular; anchorage function only •Pores: allow gas exchange; don’t close • conducting tissues absent or primitive • water required for fertilization

Bryophytes: non vascular Gemmae cups plants: Liverworts

Create liverwort Clones!

2 10/1/2012

Liverwort Bryophytes: Non-vascular plants: Moss

Bryophytes: Non vascular Hornworts! plants: Moss

3 10/1/2012

Vascular plants: Derived adaptations Vascular tissue: conducts water and nutrients throughout the plant Plant organs: roots, stems, leaves Sporophyte generation dominate (plant spends more of its life in the sporophyte (2n) generation

Lycophytes: “club mosses”

Sporophyte dominate generation Vascular tissue Stems, roots, leaves!

Strobilus: where spores are produced via meiosis

4 10/1/2012

Pterophytes (ferns and allies) • 11,000 extant species, mostly in the tropics; many extinct • Psilotales: whisk ferns(no roots) • Equisetales: horsetails • roots, stems & leaves present • sporangia variable in Sori, not strobilus

Pterophyte:Fern Life cycle TRENDS THROUGH TIME Ancestral Derived

Mosses & Liverworts Club mosses,horsetails, Plants we’ll cover next whisk ferns & ferns week…

Non-vascular Vascular Vascular Spores Spores Seeds! Gametophyte-dominant Sporophyte-dominant Sporophyte-dominant Sperm require water Sperm require water Sperm don’t need water

5 10/1/2012

Moss

 Motile sperm

 Gametophyte-dominant

 Cuticle

Gametophyte  Homospory -dominant

Gammae cups Liverworts

 Motile sperm

 Gametophyte-dominant Chlorophyta  Cuticle Gymnosperms Angiosperms Motile sperm  Gemmae cups Green algae Cuticle  Homospory Ex: Chara Pterophytes Lycophyta Seeds Strobili  Vascular tissue Lycophytes  Motile sperm

 Sporophyte-dominant

 Cuticle Vascular tissue Bryophytes  Heterospory Sporophyte-dominant  Roots and leaves Roots and leaves  Strobili Vascular tissue Pterophyta Green algae: Sori  Vascular tissue Chlorophytes  Motile sperm Land plants  Sporophyte-dominant

 Cuticle

 Heterospory

 Roots and leaves

 Sori

Gymnosperms Gymnosperms: Ginkgo Coniferophyta Long thought to be (pines and cone extinct in western bearing trees) civilization, until travelers from Cycads (palmlike) Germany found it Ginkgos (ginkgo while visiting temples in China and Japan. trees) Flagellated sperm Gnetophyta Dioecious (separate (gnetums) male and female plants) Fleshy outer covering to seed (not true fruit)

6 10/1/2012

Gymnosperms: Cycadophyta

Flagellated sperm still, but use of pollen tube Palm-like plants, but have cones for reproduction Endangered by poaching and a black market

Gymnosperms: Gnetophyta Gnetophyta: Welwitchsia Ephedra Welwitchsia Gnetum

Temperate regions Namibia Old and New except Australia World Tropics • Flower-like structures • Vessels in xylem== not found in other Gymnosperms • double fertilization • Also loss of flagellated sperm and uses pollen tube.

7 10/1/2012

Gnetophyta: Ephedra in Utah Gnetophyta: Ephedra spp.== Mormon tea oNaked seeds oUse of pollen tube oThick cuticles oPhotosynthetic stems in Ephedra

Gymnosperms: Coniferophyta  Key characteristics:  Loss of flagella on sperm, sperm conducted to egg by a pollen tube.  Needle-like or scale like leaves  Thick cuticle  Recessed stomata  Resin  Cones

8 10/1/2012

Angiosperms: the Flowering plants What are the advantages of flowering? What are the advantages to the plant? Less inbreeding Discuss the question in groups of 2-3 Higher probability the pollen will reach students the right plant 5 min They don’t have to produce as much pollen Enlists partnerships with insects and other animals

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