The Science of Classifying Organisms

Taxonomy

Classification

• GROUPING things according to their CHARACTERISTICS.

Biodiversity

• Scientists estimate that there are 5 million kinds of DIFFERENT plants, animals and microorganisms on earth.

CAROLUS LINNAEUS

• Developed a SYSTEM for grouping ORGANISMS.

CAROLUS LINNAEUS

• 1. Placed organisms into SMALLER and SMALLER groups based on SIMILARITIES.

• Similarities– STRUCTURAL -- most important– BIOCHEMICAL– GENETIC– BEHAVIORAL

Groups

• KINGDOM (largest)

• PHYLUM

• CLASS

• ORDER

• FAMILY

• GENUS

• SPECIES (smallest)

CAROLUS LINNAEUS

• 2. Gave an organism a TWO-WORD LATIN name. (binomial nomenclature)

• Example– COMMON name cougar, puma,

mountain lion – SCIENTIFIC name Felis concolor

• GENUS, SPECIESLast name, first name

Examples of Scientific Names

• Cattle: Bos taurus, Bos indicus

Examples of Scientific Names

• Cattle: Bos taurus, Bos indicus

• Sheep: Ovis sp.

Examples of Scientific Names

• Cattle: Bos taurus, Bos indicus

• Sheep: Ovis sp.

• Swine: Suidae sp.

Examples of Scientific Names

• Cattle: Bos taurus, Bos indicus

• Sheep: Ovis sp.

• Swine: Suidae sp.

• Horse: Euquis sp.

Examples of Scientific Names

• Cattle: Bos taurus, Bos indicus

• Sheep: Ovis sp.

• Swine: Suidae sp.

• Horse: Euquis sp.

• Chickens: Galus galus

SPECIES or "KIND”

• A GROUP of closely related (SIMILAR) organisms that INTERBREED and have FERTILE offspring

Biodiversity

• No SINGLE inventory (book) of ALL classified species

5 Kingdoms of living things.

• ANIMAL

• PLANT

• FUNGI

• BACTERIA (MONERA)

• PROTISTS

Using A Dichotomous Key

• Dichotomous means "BREAKING intoSMALLER parts"

Kingdom

• Encompasses large groups; such as plants, animals or fungi.

Phylum

• Subgroup within a kingdom. Animals belong to the phylum Chordata. (meaning they have a spinal “chord”)

Class

• A sub group within a phylum containing common characteristics.

Order

• A sub group within a class.

Family

• A sub group with an order.

Genus

• A sub group within a family

• Species with uniquely shared traits

• Species are thought to be closely related.

Species

• Unique group of organisms united by heredity or interbreeding

• Defined based on unique features

What’s in a name?

Dichotomous Key

• Assists in Identification

• Contains pairs of contrasting descriptions

• The key directs the user to another pair of descriptors or

• Identifies an object

3 Broad Groups• Eukaryote

– Multiple chromosomes and a mitotic cycle i.e. animals

• Prokaryote– Single-Celled does not have nucleus or membrane-

bound structures i.e. bacteria

• Archaea– Prokaryotes in extreme environments difference in

genetic make up of their cell call. i.e. bacteria in hot pots