Classification and Taxonomy

Why do scientists classify?

Why do scientists classify?

-almost 2 million kinds of organisms on earth

-need to keep organized so their easier to study

-once classified, scientists will know a lot about an organism

What is classification?

process of grouping things based on their similarities

What is taxonomy?

scientific study of how living things are classified

What did Aristotle do?

-grouped organisms into 2 kingdoms: Plantae and Animalia

-system was limited; animals grouped according to size and habitat; plants identified according to 1 of 3 stem types

What did the invention of microscopes allow scientists to observe?

-tiny microorganisms eating like animals and photosynthesizing like plants

What are 3 domains and 6 kingdoms of life?

-Domain Archae and Kingdom Archaebacteria

-Domain Bacteria and Kingdom Eubacteria

-Domain Eukarya and Kingdoms; Plantae, Animalia, Fungi and Protista

What does Prokaryotic mean?

no nucleus

What does eukaryotic mean?

nucleus

What are characteristics of organisms found in the Kingdom of Archaebacteria?

-single-celled organisms that lack nucleus

-live in extreme environments

-includes chemosynthesizers

What is chemosynthesis?

occurs in bacteria and other organisms and involves the use of energy released by inorganic chemical reactions to produce food

What are characteristics of organisms found in the kingdom Eubacteria?

-single-celled organism that lack nucleus

-live in wide variety of environments

-heterotrophic by absorption or autotrophic by photosynthesis or chemosynthesis

What are examples of organisms in kingdom eubacteria?

-cyanobacteria \n -E. coli

-Strep \n -Staph

What are characteristics of organisms found in the kingdom plantae?

-photosynthesize to make food (autotrophs)

-most sessile and multicellular

-complex and specialized cells

What are examples of organisms found in the kingdom plantae?

-mosses

-ferns

-coniferous plants

-flowering plants

-grasses

What are characteristics of organisms found in the kingdom fungi?

-obtain nutrients via decomposition (heterotrophs)

-sessile

-multicellular or unicellular

What does sessile mean?

fixed in one place; immobile.

What are examples of organisms from kingdom fungi?

-mushrooms

-mould

-yeast

-athletes foot

What are characteristics of organisms found in the kingdom protista?

-small

-unicellular or multicellular

-heterotrophs (ingets food or decomposers)

-or autotrophs (photosynthesize)

What are examples of organisms found in the kingdom protista?

Euglena and Amoeba

Who devised binomial nomenclature?

Carolus Linnaeus using Latin

How does Binomial nomenclature break down the classification of an organism?

-Domain

-Kingdom

-Phylum \n -Class \n -Order \n - Family \n -Genus \n -species

-domain is the broadest and species most specific

What is a anangram to remember binomial nomenclature?

Danish King Philip Came Over for Spaghetti

What is binomial nomenclature?

\n -The two-part scientific naming system includes the organism’s Genus (Capitalized and italicized or underlined) and species (lower case and italicized or underlined). \n -The Genus is Capitalized and italicized (or underlined if handwritten) \n - The species is lower case and italicized (or underlined if handwritten).

What is dichotomous key?

a branched or stepped process that use observable characteristics to identify an organism

How many choices at each step of dichotomous key?

only 2

What does a cladogram show?

the most probable sequence of divergence

Where are shared characteristics used in a cladogram?

between nodes (like a dichotomous keyP

What are homologous traits due to?

divergent evolution form a common ancestor (aka adpative radiation)

What are homologous traits?

similar structures but different function

What are examples of homologous traits?

-bat wings, whale fins, our arms

Can homologous traits be used for cladograms?

yes

What are analogous traits due to?

convert evolution from different ancestors?

What are analogous traits?

similar function but different structure

What are examples of analogous traits?

Bird wings and insect wings, shark fins & whale flippers

Can analogous traits be used for caladogram?

no

What is a clade?

a group of organisms that have evolved from a common ancestor (alive or extinct)

What do clades do?

-Compare primitive traits (those which evolved early on) \n to derived traits (evolved more recently as modifications \n of a previous trait)

-There is a positive correlation between the number of \n differences between two species and the time since they \n evolved from a common ancesto

What can clades use for comparison?

physical traits, DNA base sequences, amino acid \n sequences (because anatomical features can be \n analogous – they are now rarely used – DNA & a.a. \n sequences are preferred

What is the figwort family (snapdragon family)?

-Now divided into at least six

-Flower shape is convergent evolution – adapted to same types of pollinators

-Cladistics using genetics helped to split this group up