Day 6) Classification and Dichoyomous key - Life Science 11 - Joanna Peng

Taxomony

The study of classifying or organizing living things into categories based on common characteristics.

Genus

The “family group” of very similar species.

For cats, Felis is the genus.

Felis catus = domestic cat

Felis silvestris = wildcat

Binomial Nomenclature

Binomial Nomenclature is a two-name naming system. It helps eliminate confusion caused by common names and it’s written it Latin or Greek.

The names are chosen based on 3 categories:

• Characteristics of the organism (behavioral, physical, genetic)

• Commemorate a person

• Place of discovery

How do we write binomial nomenclature?

Firstly, we need to know that it’s composed of the 2 parts: Genus and species.

• The first letter of the Genus is always capitalized

• The first letter of the species is always lowercase

• Scientific names can be written in italics or underlined, but not both!

Ex. Homo sapiens or Homo sapiens

Why do we classify organisms?

1) Gives the organism a correct scientific name based on its classification, and everyone uses the same naming system. The name is used worldwide, no matter what language people speak.

2) Scientific names prevents misnomers/misleading common names like starfish or jellyfish that aren’t actually fish…

Note: Classification systems are always changing since we are always discovering more species.

What is the least specific to most specific list?

Domain —> all life split into 3 domains

• 1) Domain Archeae

• 2) Domain Eubacteria

• 3) Domain Eukaryota

Kingdom —> each domain is divided into kingdoms

• 1) Kingdom Protista

• 2) Kingdom Fungi

• 3) Kingdom Plantae (nonvascular & vascular)

• 4) Kingdom Animalia (invertebrates & vertebrates)

Phylum —> each phyla is divided into classes

Class —> each class is divided into orders

Order —> each order is divided into families

Family —> each family is divided into gena

Genus —> each genus is divided into species

Species —> one specific organism