Why Are Things Grouped?

Think of a common first name, such as Jennifer or Michael. Now, make a list of all the people you know with this name…


You should now understand why a two-name classification system is important!

_________________________ - Group things together based on similarities.

Ex: Grocery stores group items so that we can find them; School courses are grouped into "departments," Foreign Languages (Spanish, French, Italian), Science (Earth Science, Biology, Chemistry, Physics).


Why do we Classify things?




_________________________ - A feature a thing has. (Ex: Having fur, having bones)


Methods of Classification

Scientists do not always agree on how to classify living things.

__________________________, a Greek scientist, was the first person to classify living things 2,000 years ago.

He classified things as PLANTS or ANIMALS, and he further classified plants and animals according to…
                                   Green         Not green
                               Don't move      Move

           size/growth pattern      where they live  
                    trees-shrubs-herbs      air-land-water


BUT…as scientists discovered more living things, many of them did not fit into Aristotle's system. Aristotle's system became less useful.

In 1735, _____________________________________ developed a new classification system. He first placed living things into 2 main groups, or ______________________: ____________________ and ______________________.

This is the largest group of living things.

 He then organized these groups more specifically, according to traits that each group shared:


KINGDOM (largest group)

GENUS (middle group)

SPECIES (smallest group)


Linnaeus made three important changes:





Today there are seven groups for classifying organisms:

  1.                                 (Largest Group)        King
  2.                                                              Phillip
  3.                                                              Came
  4.                                                              Over
  5.                                                              From
  6.                                                             Great
  7.                                 (Smallest Group)      Spain

Having more groups makes it easier to place an organism in the proper group. For example, imagine trying to find a friend's house when all you knew was the COUNTRY he/ she lived in ???

Address Information

Classification Groups













House #


How Scientists Classify Today

  1. Classification based on how organisms are related (Organisms that are closely related will be in many of the same classification groups)

    Classifying a House Cat

    Group Group Name Group Trait
    Kingdom Animal Has many cells; eats food
    Phylum Chordate Rodlike structure along back for support
    Class Mammal Nurses young; has hair
    Order Carnivore Eats flesh; has long teeth
    Family Felidae Sharp claws; large eyes
    Genus Felis Small Cats
    Species catus Tame


    Compare the House Cat to a Lion

    Group House Cat Lion Comparison
    Kingdom Animal Animal Same
    Phylum Chordate Chordate Same
    Class Mammal Mammal Same
    Order Carnivore Carnivore Same
    Family Felidae Felidae Same
    Genus Felis Panthera Different
    Species catus Ieo Different

    Compare the House Cat to a Deer

    Group House Cat Deer Comparison
    Kingdom Animal Animal Same
    Phylum Chordate Chordate Same
    Class Mammal Mammal Same
    Order Carnivore Artiodactyla Different
    Family Felidae Cervidae Different
    Genus Felis Odocoileus Different
    Species catus virginianus DIfferent

    Compare the House Cat to an Octopus

    Group House Cat Octopus Comparison
    Kingdom Animal Animal Same
    Phylum Chordate Mollusk Different
    Class Mammal Cephalopod Different
    Order Carnivore Octopoda Different
    Family Felidae Octopodidae Different
    Genus Felis Octopus Different
    Species catus vulgaris Different
  3. Classification based on Ancestry (Related organisms that lived sometime in the past).
  4. Classification based on similar body structures (Bone structure; limbs)
  5. Classification based on Body Chemistry (cold-blooded, warm-blooded???)


Scientific Names of Organisms come from Classification

Scientific names are a combination of an organisms' _________________________ + ______________________

Scientific names are based on the _____________________language, and are written in ____________________. The first part of the name is written in __________________ case, and the second part of the name is written in ____________________ case.

__________________________ was the first person to give organisms a 2 - part name.


Common Name Scientific Name
  Felis catus
  Canis lupus
  Homo sapiens


Scientists use Scientific Names rather than common names because:







  1. _________________________ - Single-celled organisms that don't have a nucleus. (ex: bacteria, blue-green algae).
  2. _________________________ - Mostly single-celled organisms that have a nucleus & organelles. Some have chlorophyll and can make their own food. Some can move, some can not. This Kingdom is difficult to classify because they are so different from one another and from other kingdoms.
  3. _________________________ - Organisms that have cell walls and absorb food from their surroundings. They don't have chlorophyll, so they can't make their own food. (ex: mushrooms, molds, yeast).
  4. _________________________ - Organisms that are made up of many complex cells, have chlorophyll, and can make their own food (producers). They do not move.
  5. _________________________ - Organisms that have many complex cells, can not make their own food (consumers), and can move.


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