Chapter 17 Study Guide~Classification

science of naming and classifying organisms

Carolus Linnaeus
What scientist developed the classification system in the 1750’s?

What only trait use to be used to classify organisms?
Physical characteristics

Taxon + example
A group of organisms in a classification system: kingdom, phylum

Binominal nomenclature
2-part, scientific naming system

List all of the characteristics of a correctly written scientific name: (language used, font, capitalization, etc.)
Latin language, italics (underlined is also okay), Genus is capitalized, species is lowercased-
Homo sapiens (human beings)

Why are scientifically written names used more?
Universally known, less confusion, some organisms have several common names

List all taxa in order
Kingdom, Phylum, Class, Order, Family, Genus, and Species

What taxa is the biggest?

What are some limitations to only using physical characteristics for classification?
Some organisms look alike and have similar lifestyles, but aren’t closely related. (ex: sharks and dolphins)

What is available today for classification that wasn’t available of Linnaeus?
Molecular evidence (DNA/ protein analysis)

What is dichotomous key?
A classification key that helps identify something

How many choices are present at each level of the dichotomous key?

Evolutionary history for a group of species

What is phylogeny based on?
Living species, fossil record, and molecular evidence

What is a cladogram?
Branching tree diagram us king cladistics; organisms are placed by the order in which they descended from a common ancestor

Group of organisms that share a common ancestor, located across the top of a cladogram

Derived character
Trait that is shared by organisms/species on a cladogram; basis for placement on the cladogram; located along the side of a cladogram

Represents the most common ancestor shared by a clade; place where a branch splits

2 kingdoms
Plantae & animalia

3 kingdoms
+ Protista

4 kingdoms
+ Monera

5 kingdoms
+ Fungi

6 kingdoms
+ bacteria and archae (Monera split)

How many kingdoms are present today?

What Taxon has been added since Linnaeus created the classification system?