Chapter 19 Overview of Diversity

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Chapter 19Overview of Diversity

• 19-1 Origin of Eukaryotes
• 19-2 Evolution of Sexual Reproduction
• 19-3 Evolution of Multicellularity
• 19-4 Classification of Living Things

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Origin of Eukaryotes

• Bacteria, which are prokaryotes, are the oldest
  and most abundant form of life.

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Two Branches of Bacteria(Two Kingdoms of
Prokaryotes)

• Eubacteria and Archaebacteria

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The Evolution of Eukaryotes

• The evolution of organelles such as mitochondria
  and chloroplasts is explained by the theory of
  endosymbiosis.
• Eukaryotic cells evolved when certain prokaryotes
  established symbiotic relationships within larger
  cells.

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Evolution of Sexual Reproduction

• Asexual reproduction is the simplest and most
  primitive form of reproduction
• Asexual reproduction reproduction that does not
  involve the union of gametes

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Evolution of Sexual Reproduction

• One of the most important evolutionary
  innovations of eukaryotes was the ability to
  reproduce sexually
• Sexual reproduction reproduction in which
  gametes from opposite sexes unite to form a
  zygote

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Evolution of Multicellularity

• Enabled organisms to grow more complex

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Evolution of Multicellularity

• Cell specialization and coordination enable
  complex multicellular organisms to have different
  cells and different functions

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Classification of Living Things

• Taxonomy science of classifying organisms
• To ensure accurate communication about organisms,
  biologists use binomial nomenclature (two-part
  names) to name species
• Scientific name genus and species
• Example Pseudotsuga menziesii

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Classification of Living Things

• Scientists classify organisms into a hierarchical
  system of groups
• Seven basic levels of hierarchy
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

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Classification of Living Things

• A species is defined as a group of organisms that
  share many characteristics and, in nature,
  interbreed with each other and not with members
  of other species

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Kingdom Archaebacteria

• Unicellular prokaryotes
• Cell walls lack peptidoglycan
• Genes have introns
• Unique lipids in plasma membranes
• Either heterotrophic or autotrophic
• May be ancestors of eukaryotic cells
• Live in extreme environments

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Kingdom Eubacteria

• Unicellular prokaryotes
• Cell walls contain peptidoglycan
• Genes lack introns
• Reproduce asexually by binary fission
• Either autotrophic or heterotrophic
• Extremely diversified groups
• May be ancestors of mitochondria

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Kingdom Protista

• Eukaryotic organisms
• Mostly unicellular some multicellular
• Autotrophic, heterotrophic, or both
• Reproduce asexually some also sexually

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Kingdom Fungi

• Eukaryotic organisms
• Mostly multicellular some unicellular
• Cell walls made of chitin
• Filamentous bodies
• External heterotrophs principal decomposers
• Reproduce sexually or asexually

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Kingdom Plantae

• Eukaryotic organisms
• All multicellular
• Cell walls made of cellulose
• Most consist of roots and shoots
• Mostly autotrophic and terrestrial
• Highly specialized structures for reproduction
  and survival on land
• Reproduce sexually some capable of reproducing
  asexually

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Kingdom Animalia

• Eukaryotic organisms
• Multicellular no cell walls
• Most reproduce sexually
• Interior heterotrophs
• Specialized tissues
• Inhabit nearly all environments in biosphere