Diversity of Organisms
• 5 to 30 million species estimatedAxolotl
Organisms alive today descended from earlier species
• Fossils – Remains of previous forms
– Record of life’s history
• Life on Earth – Single cell organisms for
3.5 billion years
– Abundant multicellular life for 500 million years
Evolution
• Change is species over time
• Organisms alive today descended from older organisms
• Evidence is overwhelming
Organization of the Living World
• System to deal with millions of species
• An organism belongs to a unique species
Bird’s nest fungi
Organization of the Living World
• Species designated by a scientific name– Binomial nomenclature – two part name– Developed by Carolus Linnaeus– Example: Homo sapiens
• Homo = genus name
• sapiens = species name
Classification • System to organize life• Classification System
– Genus = closely related species
– Family = closely related genera
Classification System
• Domain• Kingdom• Phylum• Class• Order• Family• Genus• Species
Largest Level
Smallest Level
Methods of Classification
• Common ancestry is basis for classification
• Taxonomy = science of classifying organisms
• Systematics– Study of diversity of organisms
– Based on evolutionary relationships
Domains of Life
• Archaea
• Bacteria
• Eukarya
Cell Types of Organisms
• Prokaryote– No membrane bound organelles– Genetic material found in a nucleoid
• Eukaryote– Membrane bound organelles– Genetic material in a nucleus
Archaea
• Originally thought to be bacteria
• Live in extreme habitats
• Do not cause disease
• Prokaryotic
• Unicellular
Bacteria
• Found nearly everywhere
• Some cause disease
• Prokaryotic
• Unicellular
Eukarya
• Unicellular or Multicellular
• Eukaryotic cells
• Divided into at least four kingdoms– Protista– Fungi – Plantae– Animalia
Kingdom Protista
• Mostly single cell organisms• May actually be up to 20 kingdoms• Gave rise to other eukaryotes
Kingdom Fungi
• Most are multicellular• Absorptive heterotrophs• Most are saprophites
Diversity of Organisms
• 5 to 30 million species estimatedAxolotl
Organisms alive today descended from earlier species
• Fossils – Remains of previous forms
– Record of life’s history
• Life on Earth – Single cell organisms for
3.5 billion years
– Abundant multicellular life for 500 million years
Evolution
• Change is species over time
• Organisms alive today descended from older organisms
• Evidence is overwhelming
Organization of the Living World
• System to deal with millions of species
• An organism belongs to a unique species
Bird’s nest fungi
Organization of the Living World
• Species designated by a scientific name– Binomial nomenclature – two part name– Developed by Carolus Linnaeus– Example: Homo sapiens
• Homo = genus name
• sapiens = species name
Classification • System to organize life• Classification System
– Genus = closely related species
– Family = closely related genera
Classification System
• Domain• Kingdom• Phylum• Class• Order• Family• Genus• Species
Largest Level
Smallest Level
Methods of Classification
• Common ancestry is basis for classification
• Taxonomy = science of classifying organisms
• Systematics– Study of diversity of organisms
– Based on evolutionary relationships
Domains of Life
• Archaea
• Bacteria
• Eukarya
Cell Types of Organisms
• Prokaryote– No membrane bound organelles– Genetic material found in a nucleoid
• Eukaryote– Membrane bound organelles– Genetic material in a nucleus
Archaea
• Originally thought to be bacteria
• Live in extreme habitats
• Do not cause disease
• Prokaryotic
• Unicellular
Bacteria
• Found nearly everywhere
• Some cause disease
• Prokaryotic
• Unicellular
Eukarya
• Unicellular or Multicellular
• Eukaryotic cells
• Divided into at least four kingdoms– Protista– Fungi – Plantae– Animalia
Kingdom Protista
• Mostly single cell organisms• May actually be up to 20 kingdoms• Gave rise to other eukaryotes
Kingdom Fungi
• Most are multicellular• Absorptive heterotrophs• Most are saprophites
Kingdom Plantae
• Multicellular
• Photosynthetic autotrophs
Kingdom Animalia
• Multicellular
• Heterotrophs