Plant evolution 2012 cloutier


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High school Botany class, simplified stages of plant evolution

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Plant evolution 2012 cloutier

  1. 1. Plant Evolution by Annie Cloutier 2012From a single cell to multi-cellularPlants are the quiet autotrophs who changed the planet acloutier2012 copyright 1
  2. 2. Photons are particles of sunlight that autotrophs use to create living plant cells acloutier2012 copyright 2
  3. 3. acloutier2012 copyright 3
  4. 4. Life and its journey through time acloutier2012 copyright 4
  5. 5. Land plants evolved over a 450 million years time I am an aquatic plant I am a terrestrial plant acloutier2012 copyright 5
  6. 6. From the oceans and ponds migrating to land acloutier2012 copyright 6
  7. 7. Stages of plant evolution include:• From aquatic to terrestrial environments• Developed of a vascular system (xylem and phloem)• Developed a root system• Evolved from spores to seeds• Designed more complex pollination methods , many with symbiosis• Gametophytes to sporophyte• Development of angiosperm (flowers)• Naked seeds (gymnosperm) to enclosed seeds (angiosperm) acloutier2012 copyright 7
  8. 8. Algae > Green Red & Brownevolved from cyanobacteria acloutier2012 copyright 8
  9. 9. Kingdom Plantae• Phylum Hepaticophyta (liverwort)• Phylum Anthocerotophyta (hornwort)• Phylum Bryophyta (mosses)• Phylum Psilotophyta ( whisk fern)• Phylum Lycophyta (club mosses)• Phylum Polypodiophyta (conifers)• Phylum Ginkgophyta (Ginkgo)• Phylum Cycaophyta (Cycads)• Phylum Gnetophyta (Gnetum, Epherdra,Welwitschia)• Phylum Magnoliophyta (flower plants) – Class Magnoliopsida ( dicots ) – Class Liliopsida ( monocots ) acloutier2012 copyright 9
  10. 10. How did scientist decide how to classify plants ?• Plants are organisms with multi-cellular reproductive structures• Some plants do not have true xylem or phloem• Plants that have true xylem and phloem• Plants with true leaves• Plants with branching• Plants with stems• Plants with veins and silica• Plants that reproduce by spores• Plants reproduce by clones• Plants reproduce by seeds acloutier2012 copyright 10
  11. 11. What’s a taxonomist ?• The cladogram chart shows the relationships between organisms and their development and characteristics.• It is also known as the “evolutionary trees” of living organisms• A taxonomist uses cladistics in the process of establishing a relationship among organisms. Much of the taxonomist work is inferred evolutionary relationships• So a taxonomist construct keys to aid in the identification of organisms. Most keys are dichotomous (branching lines), dealing in generalities which can have occasional exceptions acloutier2012 copyright 11
  12. 12. An example of a dichotomous key acloutier2012 copyright 12
  13. 13. acloutier2012 copyright 13
  14. 14. How does it work ? Have you used a dichotomous key form ?• Kingdom: Plantae• Phylum: Magnoliophyta• Class: Liliopsida• Order: Liliales• Family: Liliacae• Genus:Allium• Species: Allium cepra L.• Common name “onion “ acloutier2012 copyright 14
  15. 15. Since Linnaeus’ time and early botanical nomenclature…• A number of classification categories have been added between the levels of kingdom and genus.• The Genera are now grouped into families• Families into orders• Orders into classes• Classes into divisions (or phyla)• And divisions into kingdoms• Latin names are uses internationally so all scientist learn the same vocabulary to identify plants acloutier2012 copyright 15
  16. 16. Who tried to organize the plant world first ?• Greek Theophrastus 4th century B.C. he classified 500 plants !• 13th century a distinction was made between monocots and dicots• 18th century European scholars began using Latin for the first word genera groups (genus is single)• Today Swedish naturalist Carolus Linnaeus’ 1707- 1778 designed a system of classification that is still used around the world.• He frequently lead field trips through the country-side to identify plants accompanied musical band acloutier2012 copyright 16
  17. 17. Learning can be fun ! acloutier2012 copyright 17