Classification, Kingdoms, & Domains (Study For Quiz!)

Classification

The process of grouping things according to their similarities.

Aristotle

The Greek scientist who was the first to classify organisms by their features over 2,000 years ago.

Linnaeus

The Swedish naturalist/botanist. In the late 1700's, he developed a system of grouping and naming based on an organism's structures.

Phylogeny

An organism's evolutionary history (how the species has changed over time).

Phylum

The third largest of the 8 levels of classification; means tribe or race.

8 levels of classification (in order from largest).

Domain, kingdom, phylum, class, order, family, genus, species Hint: Dear Kind Professors Can't Often Fail Good Students!

Kingdoms

A common classification system used today groups all organisms into 6 _________________ based on their most basic characteristics.

Binomial nomenclature

The 2-word naming system Linnaeus developed to name the various species.

Genus

A group of similar species. The first word in an organism's scientific name.

Species

A group of organisms that share similar characteristics and can reproduce among themselves to produce fertile offspring (green textbook pg. 154).

Scientific name format

The genus is written first and begins with a capital letter. The species name is 2nd and starts with a lower case letter. Ex: Homo sapiens (Humans)

Field guide

An Identification tool with illustrations, photos, etc. Contains general information about the organism and usually its common and scientific name

Dichotomous key

A detailed list of identifying characteristics that uses paired statements to identify and name a species.

Taxonomy

The scientific study of classification.

Four functions of scientific names.

1. Avoid mistakes, 2. organisms with similar phylogeny grouped together, 3. gives descriptive information about the species, 4. allows information about the organism to be organized and shared efficiently.

Modern classification

Classification based on phylogeny- similar structures, cell characteristics, number of chromosomes and DNA, fossil evidence, and early stages of development, etc.

State Aristotle's and Linnaeus' contributions to classifying living things

Aristotle- the first to classify: 2 major groups, the plants and animals. Linnaeus' system was based on structural similarities and used 7 levels (starting with the kingdom) and binomial nomenclature.

Identify some specific characteristics that are used to identify organisms

Some examples: hair, scales, feathers, gills, cell type, etc.

How might Aristotle have classified a turtle, kangaroo and dog?

He might have put the dog and kangaroo together because they both have hair (although he might have grouped the turtle and dog together because they both have 4 legs).

Problems with Aristotle's system

Closely related organisms are not always grouped together. For example, the whales' closest living relative is the hippo, but Aristotle would have grouped whales with the fish, not the land animals.

Domain

Largest classification level. There are 3.

Taxon

The scientific name for a classification level or group.

Number of kingdoms currently recognized.

Six

Number of domains currently recognized

Three- the Archaea, the Bacteria, and the Eukarya.

Prokaryotic Kingdoms

Archaea & Bacteria

Eukaryotic Kingdoms

Protista, Fungi, Plantae, Animalia

Prokaryotic

Organisms whose cells don't have a nucleus and organelles.

Eukaryotic

Organisms whose cells have a nucleus and organelles.