Chapter 14

Classification of Organisms

• How do we tell the difference between related individuals?

– Different first name

– Same last name

• Science is slightly different

Section 14.1

Categories of Biological Classification

Taxonomy

• Taxonomy– The science of naming and classifying

organisms

• Created to make it easier to tell the difference between all organisms on Earth

• Taxonomy uses Latin language

A Simpler System

• Binomial Nomenclature– Two-word system for naming organisms

• Invented by Swedish scientist, Carl Linnaeus

• First word = genus

• Second word = species

Scientific Names• Binomial nomenclature = scientific name

• Genus– A taxonomic category containing similar

species

• Helps describe the difference between organisms with the same name

• p. 301 – Table 1

Classifying Organisms

• Consists of 8 levels– p. 302 – fig. 2

• Starts with the most broad and ends with most specific descriptive

Classifying Organisms• Domains

– Contain similar kingdoms

• Kingdom– Contain similar phyla

• Phylum– Contain classes with similar characteristics

• Class– Contain orders with similar characteristics

• Order– Contain similar families

• Family– Contain genera with similar characteristics

• Genus – Contains species

• Species

Classifying Organisms• Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Create a Mnemonic

• Create a mnemonic to remember the organization of the levels of classification in the correct order.

• Ex: Do Kids Post Crap On Facebook? Generally So

• Create your own and share with your table partner.

Classification of the Honeybee

• Domain– Eukarya

• Kingdom– Animalia

• Phylum– Arthropoda

• Class– Insecta

• Order– Hymenoptera

• Family– Apidae

• Genus– Apis

• Species– Apis mellifera

Section 14.2

How Biologists Classify Organisms

• With a partner, describe how you would organize a closet full of clothes so things seemed to be in a logical order.– Color– Long-sleeve– Short-sleeve– Fabric– Buttons– No buttons– Hoods– No hoods

What is a Species?

• Biological Species– A group of natural populations that are

interbreeding or could interbreed, and that are reproductively isolated from other similar groups.

• Reproductive Isolation– Occurs when a barrier separates two or more

groups of organisms and prevents them from interbreeding

• Hybrid– Occurs if individuals of different species interbreed

Number of Species• Many more species exist than are described

• New species are being discovered

• There are currently around 1.5 million species

• Scientists believe there are 5 to 10 million species (in the tropics alone) that have not yet been described

• The earth is more diverse than we think

Evolutionary History• Phylogeny

– Evolutionary history of an organism

• Convergent evolution– Organisms may have similar characteristics due to

developing in similar habitats

• Analogous characters– Similarities that occur due to convergent evolution

• Wings of birds and insects

Cladistics

• Cladistics– Method of analysis that reconstructs

phylogenies by inferring relationships based on shared characteristics

• Ancestral character– Occurs when the characteristic is found in

common ancestors• Backbone of birds and mammals

Cladistics• Derived character

– Evolved in an ancestor of one group but not another• Birds have feathers and mammals don’t

• Cladogram– Branching diagram

that shows the

evolutionary

relationships among

groups of organisms

Data Lab – p. 309

• Materials (per group):– Whiteboard– 1 marker– Eraser

• Task– Create a cladogram for the 3 plants.– Answer the 3 Analysis Questions on your

whiteboard