Evolutionary history of Biological diversity

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Evolutionary history of Biological diversity
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• 2.7 billion yrs ago oxygen
• 2.1 billion years ago eukaryotes
• 1.7 billion years ago multicellular euk.
• 500 million years ago plants, fungi, animals

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Gram staining
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Nitrogen fixation
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-Eukarytoic -Mostly unicellular -Aerobic
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Endosymbiotic theory
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Green algae ? Land Plants

• Evidence
• Similar chloroplasts
• Cellulose walls
• Peroxisomes
• sperm

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Bryophytes

• Mosses/liverworts/
• hornworts
• Reproduce using spores
• Avascular
• Gametophyte is
• dom. stage

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Pteridophytes (ie ferns)

• Vascular
• No flowers or seeds
• Use spores
• Sporophyte dom. life cycle
• Kind of in between bryophytes and
  angiosperms/gymnosperms

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Alternation of generations
2 multicellular stages -gametophyte
(haploid) -gametes are produced -sporophyte
(diploid) -fertilization of egg by sperm forms
sporophyte
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Gymnosperms
conifer
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Angiosperms (flowering)

• Monocots
• Parallel veins
• 1 cotyledon (seed leaf)
• Dicots/Eudicots
• Netlike veins
• 2 cotyledons

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Double fertilization
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mycelium
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lichens
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Sponges (parazoa)

• Filter feeders

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Cnidarians
Radial symmetry
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Platyhelminthes (flatworms)
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Nematoda (round worms)
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Molusca
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Annelida

• Segmented worms

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Arthoropoda

• Segmented, exoskeleton
• bilateral

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echinoderm