What's in a Name?
These two activities introduce students to scientific taxonomy
as well as creating,
dichotomous keys. The first activity models the dichotomous key
the students determine the
identity of polar species of the Order Pinnipedia.
The second activity brings a bit of the background in how
naming is done and leads the
students into creating penguin Families based on physical
The students create the Family
names using provided Latin and Greek root words as "building
toward names that describe the
Taxonomy and using a dichotomous key to classify organisms are
concepts that students need to
understand in Biology. When asked to use scientific names,
students are often intimidated since
many names are long and strange sounding. Penguins are a
favorite topic of
students. There are only 18
species in the entire world, making them a manageable number to
is only one Family in the
Order Sphenisciformes although there are 6 genera and there are
three distinct body types. By
using Latin and Greek root words to describe each new Family
students can see how
scientific names usually relate to the animals being named. By
dichotomous key, the students
can more readily understand how they work.
Middle School through High School
Using the high interest generated by polar animal species
- To use a dichotomous key to identify animal species
- To create a dichotomous key
- To create scientific Family names using the same word roots as used by
Teacher Preparation for
Copy Student Masters. Penguin pictures may be copied onto tag
easier manipulation when
Student Masters on Pinnipedia Pandemonium; Classy Penguins;
and Greek word roots; Pinnipedia
pictures and descriptions
One class period
Engagement and Exploration (Student Inquiry Activity)
Students use a dichotomous key to determine the species of
Pinnipedia. Students should cut out
and arrange the various pinnepeds by Family once the identities
Discuss with students what characteristics they felt scientists
group the pinnipeds in this manner.
Determine the meanings of the Family names by looking the Parts
names up in the word root
Discuss with students the history of taxonomy as developed by
Linnaeus and the rules
established for scientific names.
Model designing a dichotomous key by using common objects such
as pens and
Elaboration (Polar Applications)
Students create at least three Families for the 18 species of
Family names should be
developed by using Latin and Greek root words. Students then
dichotomous key to identify
the Families and individual penguin species.
Exchange (Students Draw Conclusions)
Students share the characteristics used to determine different
and come to consensus on how
many families there should be and proper names for these
families based on
characteristics and root
Evaluation (Assessing Student Performance)
Dichotomous key product should be graded on completeness,
proper flow, and
used for identification of families and species.
Names should be evaluated on logical use of root words based
Pearland High School
3775 S. Main Street
Pearland, Texas 77581
Student Reproducible Masters
Scientists use dichotomous keys to help them determine the exact species
of an organism. Dichotomous means two choices. Either the organism fits
into one choice or the other given. You move to the step number given. As
you move down through the choice steps, eventually your organism should
be described and named.
The following pictures of the Order Pinnipedia (seals, walruses, sea
lions, etc.) are described in the key. Not every organism on the
dichotomous key is pictured.
In this exercise, only the common name is given.
Dichotomous Key for Polar Pinnipeds
- What characteristics were used in the key to describe the pinnipeds?
- Use the Greek and Latin root names to determine what "pinni" in
- To what do you think "ped" refers?
- What part of the animal do you think distinguishes it (makes it
different from) other types of animals, such as a dolphin?
- What parts of the anima}s were the hardest to figure out? In other
words, what sections of the key did not work as well for you? Is there a
way the key could have described that part better? How?
||A. Long tusks - large - up to 1,215 kg
||Family Odobenidae Walrus
||B. No long teeth extending beyond mouth
||Go to 2
||A. Head with small ear flaps. Able to walk with hind flippers.
||Family Otariidae Go to 3
||B. Head with small holes only at eardrum
||Family Phocidae Go to 9
||A. Rounded noses, short front flippers, rough fur
||Go to 4
||B. Pointed noses, long front flippers & thick fur
||Go to 5
||A. Sleek, agile high forehead
||California sea lion
||B. Stocky, low forehead
||Northern sea lion
||A. Back and sides gray to brownish w/ high forehead
||Go to 6
||B. Very short snout
||Go to 7
||A. Head withcrest
||Subantarctic fur seal
||B. Head without crest
||Antarctic fur seal
||A. Black with reddish belly
||Northern fur seal
||B. Back only or entire body gray
||Go to 8
||A. Fairly evenly gray all over
||Juan Fernandez Fur Seal
||B. Gray back and gingery belly
||South American Fur Seal
||A. Heavily built, male w/large nose capable of ballooning
||Go to 10
||B. No large nose pouches
||Go to ll
||A. Large body grayish brown all over- no markings
||So. Elephant seal
||B. Body mottled with dark brown or black markings
||A. Body with large, more defined markings
||Go to 12
||B. Body with spots, mottled or no markings
||Go to 13
||A. Creamy body with dark head and circular dark patch on back
||B. Dark body with buffy rings around neck and flippers
||A. Large heavily bodied
||Go to 14
||B. Small to medium bodied - may have chin stripes
||Go to 16
||A. Heavy lower jaw - dark back with spotted side and belly
||B. Long snout but small lower jaw
||Go to 15
||A. Body patterned with little to heavy patches and lines
||B. Body Grayish brown- large, long and smooth whiskers
||A. Mottled patterns on body
||Go to l7
||B. Body coloration with little or no mottled areas
||Go to 18
||A. Barrel shaped body - mouth line up-turned - patches on sides and
||B. Highly variable patterns - mottled spots on back and belly
||A. Slim body - elongated snout w/tip tilt up - creamy color
||B. Plump w/ small head - dark back and silver belly - stripes on
The man who established how scientific names should be created was Carolus
Linnaeus. He chose to use Latin roots of words in naming organisms. He
even "Latinized" his own name which was onginally Carl Von Linne'
Linnaeus used common traits of organisms to group them.
Some of the rules Linnaeus established were that:
At present, there is only one Family to which all the penguins belong.
scientists believe that the penguins should have at least three Families
or subfamilies to
accommodate the differences between the penguins.
- Organisms should show genetic relationships to each other through
the genus name.
- The species name, made up of the genus and the trivial names, was
to further descnbe the organism.
- Only the genus Is capitalized
- The entire scientific name should be italicized or underlined
How should the world's penguins be classified?
Penguin illustrations, list of Latin and Greek roots of words
- Carefully observe the illustration of all the
- Note any repetition of traits such as body size, feather
pattems, beak shapes, or color.
- Common traits can be used to create a dichotomous key to
identify penguins. Your task is to create three or more Families for the
penguins based upon their physical characteristics. You will also name
those Families by using Latin and/or Greek word roots so that each name
reflects the characteristics of the penguin Family.
- Use the following format to create a key that anyone could
use to identify and classify the penguins. The numbers must lead the user
from one step to the next. One cannot skip down to a step without a "Go
5a. Has . ( Now begin describing all the traits that separate the
different "Y" trait penguins. I just guessed at 2a's "Go to 14" You would
actuaily use whatever number came after you finished keying all the "Y"
trait penguins )
|1a. Has trait "X"
||Go to 2
|1b. Has trait "Y"
||Go to 5
|2a. Has trait"Z"
|2b. Has beak of another color
||Go to 3
|3a. Has black beak
|3b. Has other colored beak
||Go to 4
|4a. Has purple beak
|4b. Has spotted beak
* Made up names. You will use the correct scientific names from
the list your teacher has.
** Made up names - You will make up your own. HlNT:Use the word
roots to create Family or Subfamily names.
Compare your classification key to those of others
around you. Dld you plck out the same charactenstics as the others? If
not, what were the tralts you picked out versus the others?
How do scientists decide to what Family an animal
What problems can this method cause in classifying
What method for classifying are scientists now
using? Do you think this will be more accurate? Why or why not?
look forward to hearing from you! Please review this activity.
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