Classification

S7L1a: Students will be able to compare organisms by similar and dissimilar characteristics.

S7L1b: Students will be able to classify organisms into the six kingdoms based upon these characteristics.

Characteristics of Living Things

All have cells

All have chemicals needed for life

All respond to stimuli

All use energy

All grow and develop

All reproduce

Cell Theory

All organisms are made of one or more cells

The cell is the basic unit of all living things

All cells come from other cells

Tools Scientists Use to Classify Organisms

Branching Diagrams

Dichotomous Key

Eight-Level System

Binomial Nomenclature

Branching Diagrams – show the evolutionary relationships amongst organisms.

Dichotomous Key – a tool used to identify organisms and consists of the answers to a series of questions.

The questions are asked in pairs, and the answers are in yes or no format.

Eight-Level System – organisms are placed in categories from least similar to most similar based upon shared characteristics

Binomial Nomenclature – a two-part scientific name

Scientific Name = Genus + species

Genus name is capitalized or can be abbreviated

Species name is lower case

Example: Homo + sapiens Homo = Genus sapiens = species

Scientific name is Homo sapiens, which means “knowing man”

Three Domains and Six Kingdoms

Classification into Domains and Kingdoms

Organisms are classified into Domains and

Kingdoms based upon the following three

characteristics:

Cell type

How they get their food

Number of cells inside their body

Two Cell TypesProkaryotes

Single-celled organisms (unicellular)They do not have a true nucleusDo not have membrane-bound organellesEx: Archaea and Bacteria

EukaryotesMultiple-celled organisms (multicellular)Have a nucleusHave membrane-bound organellesEx: Humans, Protists, Plants, and Yeasts

Domain Archaea

Kingdom – Archaebacteria

Characteristics:

Prokaryotes –single-celled organisms

Do not have a nucleus

Live in extreme environments

Domain Bacteria

Kingdom – Eubacteria

Characteristics:

Prokaryotes –single-celled organisms

Do not have a nucleus

Live in the soil, water, on and inside the human body

Some cause disease, while others help fight disease-

causing bacteria

Domain Eukarya

Kingdoms: Protista, Fungi, Plantae, and Animalia

Characteristics:

Have a nucleus

Membrane bound organelles

Protozoans Fungi Plantea Animalia