Unit: Classifying Living Things
Section: Features and Naming
Key Words: organism, classification, genus, species, Linnaean system
Essential Questions:
-
How do scientists classify organisms?
What are some common features that scientists use to classify organisms?
What is the Linnaean system of classification?
Species
-
a group of organisms with members that produce among themselves in their natural environment
millions of different species on Earth
Taxonomy – Linnaean System of Classification
o Carolus Linnaeus helped organize living things into a hierarchy
o Looks at similar characteristics of organisms and groups them
Physical
Behavioral
• Skeletal structure
• Body symmetry
• Presence of body
covering
• feathers, hair, scales,
etc
o
o
• Food sources?
• Gather food sources?
• Live in groups or solitary?
Shows connection between organisms
Break down for Linnaean Classification:
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Genetic/Chemical
• Genetic makeup/composition
• source of energy
• single/multi-celled
• autotroph/heterotroph?
• asexual/sexual
reproduction?
o
Present
 Still use Linnaean classification but with a domain added before Kingdoms
 Domains
Archaea
o Single-celled organisms
o No defined nucleus
o Chemical makeup is different from other bacteria
o Able to survive in harsh conditions
Bacteria
o Single-celled organisms
o Common and list most everywhere
o No defined nucleus
o Some can cause disease
Eukarya
o Both single and multi-celled organisms
o Have a defined nucleus
o Breaks into 4 kingdom
Domain
• Archaea
• Bacteria
• Eukarya
Kingdom
• Protista
• Fungi
• Plantae
• Animalia
Evolution – change in hereditary features of a species over time
-
Jean Baptiste de Lamarck – 1809
o French Scientist
o 1st to hypothesize how species evolved
o offspring keeps traits that their parents evolve
o characteristics not used are lost in the gene pool
o “theory of acquired characteristics”
 ex. weight lifting parents produce children with stronger and larger muscles