classification of living things - pearland high school · classification of living things. domains...
TRANSCRIPT
Tacitus bellus
Populus tremuloidesQuaking Aspen
Finding Order in Diversity
• *To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner. All Scientist will be using the same name
• Taxonomy is the branch of biology that groups and names organisms based on studies of their different characteristics.
• Biologists who study taxonomy are called taxonomists.
• Classification systems change with expanding knowledge.
Carolus von Linnaeus(1707-1778)
Carolus Linnaeus• Swedish botanist
• Developed Binomial Nomenclature
• ***All Scientist will be using the same scientific name.
• Two-word naming system– Genus
» Noun, Capitalized, Underlined or Italicized
– Species
» Descriptive, Lower Case, Underlined or Italicized
– Each species is assigned a two-partscientific name
» Ex. Ursus arctos
System of Classification
• Linnaeus’s hierarchical system of classification includes eight levels (from largest to smallest)
• Grizzly Bear (common name)
– Domain Eukarya
– Kingdom Animalia
– Phylum Chordata
– Class Mammalia
– Order Carnivora
– Family Ursidae
– Genus Ursus
– Species arctos
Each of the levels is called a TAXON
Ursus arctos(scientific name)
System of Classification
• Taxonomic categories, an acronym:– Domain Dear
– Kingdom King
– Phylum Phillip
– Class Came
– Order Over
– Family For
– Genus Good
– Species Soup
KPCOFGS
• Phylogeny – evolutionary relationships among organisms
• Evolutionary classification –strategy of grouping organisms together based on their evolutionary history– Fossil record
– Comparative homologies
– Comparative sequencing of DNA/RNA among organisms
– Molecular clocks
Evolutionary Classification
Molecular Clock
Allows scientist to compare DNA sequences from two species to estimate how long it has been since they diverged from a common ancestor
Taxonomic Diagrams
Phylogenetic Tree: Represent hypothesized evolutionary relationships
Mammals Turtles Lizards and Snakes Crocodiles Birds
Looks like a
Branch on a
tree
Attempt to trace the
process of evolution by
focusing on shared features
CladogramTaxonomic Diagrams
Which
organism is
the
outgroup
Mammals
Which 2
organism
are more
closely
related
Crocodiles
and birds
The more
specific
you get,
the more
options
you have.
(3)
(6)
(32)
(90)
(493)
(5,404)
(94,240)
(953,434)
Dichotomous Keys Identify Organisms
• Dichotomous keys contain pairs of contrasting descriptions.
• After each description, the key directs the user to another pair of descriptions or identifies the organism.
Example: 1. a) Is the leaf simple? Go to 2
b) Is the leaf compound? Go to 3
2. a) Are margins of the leaf jagged? Go to 4b) Are margins of the leaf smooth? Go to 5
Domains (Notice the domains on the chart)
• Most inclusive category
• Larger than a kingdom
• There are 3
– Eukarya – includes the kingdoms
» Protists, Fungi, Plants & Animals
– Bacteria – corresponds to the kingdom Eubacteria
– Archaea – corresponds to the kingdom Archaebacteria
Kingdoms
• (Eubacteria and Archaebacteria) Prokaryotes, with or without peptidoglycan in cell walls
• Protista – Eukaryotes, diverse, not fungi, plants, or animals
• Fungi – Eukaryotes, multicellular (except yeasts), heterotrophic, chitin in cell walls
• Plantae – Eukaryotes, multicellular, autotrophic, cell wall containing cellulose
• Animalia – Eukaryotes, multicellular, heterotrophic, no cell wall
Kingdom -Eubacteria
• Common name: Bacteria
• Unicellular prokaryotes
• Peptidogylcan in cell wall
• Ecologically diverse
• Basic shapes are cocci, bacilli, spirilla
• Reproduce both sexually and asexually
Bacillus anthracis(spores can live in soil
for years)
Streptococcus mutans(can cause endocarditis
and dental caries)
Kingdom -Archaebacteria
• Cell wall does not contain peptidogylcan
• Cell membrane contains unusual lipids not found in other organisms
• Live in extreme environments (devoid of oxygen):
– volcanic hot springs
– brine pools
– black organic mud
Archaea
first detected in extreme
environments, such as volcanic hot
springs.
Kingdom Protista
• A classification problem – consists of organisms that cannot be classified as animals, plants, or fungi
• Most unicellular, some colonial and some multicellular
• Autotrophic and heterotrophic
• Some move with flagella, pseudopods or cilia
• Animal-like, plant-like and fungus-like groups
• Reproduce by mitosis and meiosis
Entamoeba histolytica
Kingdom Fungi
• Most feed on dead, decaying organic matter by secreting digestive enzymes into their food source then absorbing it into their bodies
• Cell walls of CHITIN
• Most multicellular; some unicellular
• Heterotrophic
Boletus zelleri(Edible, but often infected with fly
larvae)
Epidermophyton floccosum
(one of the causes of athlete's foot)
Kingdom Plantae
• Multicellular
• Nonmotile – cannot move from place to place
• Cell wall with cellulose
• Mostly photosynthetic autotrophs
Sunflowers in Fargo, North Dakota
Ginkgo bilobaGinkgos are often very
long-lived. Some specimens are thought to be more than 3,500
years old.
Kingdom Animalia
• Multicellular
• Heterotrophic
• No cell walls or chloroplasts
• Incredibly diversity
Hymenoptera Dialictus zephrum
Txodes scapularisDeer tick
Hierarchical Systemof Classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
• From general
to more
specific
Ecotherms vs Endotherms
• Ectotherm, Any so-called cold-blooded animal; that is, any animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface. The ectothermsinclude the fishes, amphibians, reptiles, and invertebrates.
• Endotherm, so-called warm-blooded animals; that is, those that maintain a constant body temperature independent of the environment. The endotherms primarily include the birds and mammals.