Name
Date
Class
Content Practice A
LESSON 2
Classifying Organisms
Directions: On each line, write the term from the word bank that correctly completes each sentence. Some terms
may be used more than once.
binomial nomenclature
cladogram
dichotomous key
domains
genus
kingdoms
scientific name
species
systematics
1. Based on similar structures, Linnaeus classified all organisms into two
Kingdoms
.
2. As more discoveries were made, Whittaker proposed classifying organisms into five
Kingdoms
.
3. The current system of classifying organisms uses molecular analysis and is called
Systematics
.
4. The current system classifies organisms into three Domains
Kingdoms
and six
.
5. Scientists still use Linnaeus’s naming system called Binomial Nomenclature to give
each species a name.
6. Ursus arctos is the Scientific Name
7. Ursus is the brown bear’s Genus
8. The word arctos is the brown bear’s Species
for a brown bear.
.
name.
9. A Dichotomous Key is a series of questions that helps you identify an
unknown organism.
10. A branched diagram called a Cladogram
can help you understand the
relationships among organisms.
30
Classifying and Exploring Life
Name
Date
Content Practice B
Class
LESSON 2
Classifying Organisms
Directions: Answer each question or respond to each statement on the lines provided.
1. Aristotle classified all organisms into two groups—plants and animals. Why did
Whittaker propose a five-kingdom system?
More organism were discovered that wouldn’t fit in the previous two kingdoms. When new organisms
are discovered, they need to be classified. If the current classification system doesn’t work for the new
organism, then the system needs to be revamped.
2. What is the current system for classifying organisms called? What evidence does it use
to classify organisms?
The current system is called Systematics. It uses all the know information about the organism such as
cell type, habitat, molecular analysis, way of obtaining energy and food
3. What is binomial nomenclature?
A specific way of giving all organisms a unique two part name
4. Explain what makes up a scientific name.
The Genus and Species
5. How would you use a dichotomous key to identify an organism?
Match descriptions from the key to observable characteristics of the organism
6. How does a cladogram show the relationships among organisms?
Cladograms show shared characteristics among organisms the more characteristics they share, the closer
the relation.
Classifying and Exploring Life
31