Classification Notes (cont.)
Classification Notes
(cont.)
• As we move from kingdom to species, organisms within each taxon become more similar to one another.
• Taxon: A group of similar organisms
How do we classify?
• By cell structure, food-getting methods and metabolism, external coverings.
• DNA and genetic code is increasingly more important.
• Classification of organisms is not perfect-some organisms are reclassified when more is learned about them.
• Some have even suggested adding more kingdoms.
Level of
Classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
Human
Animalia
Chordata
Mammalia
Primates
Hominidae
Homo sapiens
Domestic Cat Grizzly Bear
Animalia
Chordata
Mammalia
Carnivora
Felidae
Felis silvestris
(domesticus)
Animalia
Chordata
Mammalia
Carnivora
Ursidae
Ursus arctos
1. At which taxon do you start to see differences?
2. Which two of the three organisms are more related?
3. At what point do the classifications of the cat and grizzly bear diverge?
Binomial Nomenclature
(two name naming)
• Every scientific name is made of two words (binomial)
• First word is Genus is capitalized
• Second word is Species name and is lowercase
• Genus functions as a noun, Species functions as an adjective.
-Genus: noun
-Species: adjective
Examples:
Genus Homo sapiens species
Genus Felis silvestris species
Genus Ursus arctos species
Be able to look at a scientific name and determine which two organisms are the most closely related.
Of the three choices below, which two are the most closely related?
I. Red hat
II. Blue hat
III. Red ball
Answer: the Red hat and the Blue hat. They are closest related because their nouns are the most similar. The adjective only describes the noun.
Now, which of the following three pairs are the most closely related? Why?
I. Mus domesticus
Musca domestica
II. Galleus domesticus
Mus domesticus
III. Felis concolor
Felis rufus
Genus
1. Mus domesticus
Musca domestica
2. Galleus domesticus
Mus domesticus
3. Felis concolor
Felis rusus
Answer: Pair 3 species of a particular genus mouse fly chicken mouse cougar bobcat
Noun Adjective
If someone asks you which organisms are most similar, look for ones with the same “noun” as 1 st word.
