Page 55 - Science Course 1 (Book 1)

Categorizing Organisms Mo2-L3a: How are Organisms Classified?
Lesson 3

Dichotomous Key

a series of descriptions arranged in pairs that
In this topic, you will learn the following lead the user to the identification of an unknown
organism.
lessons: Organism
Mo. 2 - L3a: How are Organisms Classified?
Does not
have six legs Six Legs
Mo2-L3a How are Organisms Classified?

KEY CONCEPTS: No antennae Have antennae
1. What methods are used to classify living things
into groups?
2. Why does every species have a scientific name?
No Large Large hind
hind legs for legs for
Vocabulary A-Z hopping hopping

Let us learn some vocabulary

Binomial Nomenclature
a naming system that gives each organism a two Ant Grasshopper
word scientific name.
Species
American Cockroach a group of organisms that have similar traits and
Periplaneta americana are able to produce fertile offspring.

Kigndom: Animalia
Phylum: Athropoda
Class: Insecta
Order: Blattaria
Family: Blattidae
Genus: Periplaneta
Species: P. americana Species
Cladogram

a branched diagram that shows the relationships
among organisms, including common ancestors.

Class Mammalia
Order Carnivora
Family Felidae

Turtle
(Outgroup) Horse Wolf Leopard Domestic Cat

Ability to purr
Retractable claws

Carnivorous
(meat-eating teeth)
Hair

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