1. How Do Scientists Identify and Classify New Species?

3. Carolus Linnaeus ( )
·Swedish botanist / physician that collected plants for their curative properties & needed to organize his collection.
·Contributed to the development of our modern system of taxonomy.
·Developed binomial nomenclature, a two-word naming system still used today.
Each species is assigned a two-part scientific name

4. Dashing
King
Philip
Came
Over
For
Great
Soup
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

5. Odocoileus virginianus
Homo sapiens
What's My Name?
Canis lupus
What's My Name?
Human
Dog
Odocoileus virginianus
What's My Name?
What's My Name?
Pecari tejacu
Javelina
White-tailed Deer

6. KINGDOMS CLICK THE CROWN:
The three domains each contain at least one kingdom. Domains Archaea and Bacteria both contain all the prokaryotes and include organisms from the kingdoms Archaebacteria and Eubacteria. The four remaining kingdoms are all found within the Domain Eukarya.

8. Check for Understanding
FIRST CELL
Kingdom
Plantae
DOMAIN
BACTERIA
Kingdom
Fungi
Kingdom
Eubacteria
DOMAIN
EUCARYA
DOMAIN
ARCHAEA
Kingdom
Archaebacteria
Kingdom
Protista
Kingdom
Animalia
Erase the areas that each arrow is pointing to in order to reveal the information "hidden" below...
Check for Understanding

9. Check for Understanding

11. Identifying Organisms
The names given to organisms often reveal:
- The evolutionary history of their species
- Ecological relationships with other species
- Distinguishing characteristics of that species
Common names are often confusing
- Not all are fish: catfish, starfish, silverfish, jellyfish, crayfish
In order to study this diversity:
- Species are grouped into larger related classifications
- A universal scientific name is given to every species
A dichotomous key is a series of questions used to identify new or unknown species. (eg. flower)

12. Identifying Organisms
Questions
1. Give three examples of flower characteristics used in the dichotomous key.
2. Which flower did you classify as a crucifer? Describe two flower characteristics you think may be useful in identifying flowers from other crucifer plants.
3. How do you think white cabbage butterfly larvae might identify crucifer plants?
Identifying Organisms
Using a dichotomous key
With millions, and perhaps billions, of different
species on Earth, identifying organisms can be quite a challenge.
Luckily, a simple set of questions, called a dichotomous key, can systematically lead a scientist from unknown to known.
Try this dichotomous key activity to learn how this works. Then, answer the questions found in the tab
on the left.
Answers
1. Give three examples of flower characteristics used in the dichotomous key.
The three flower characteristics were the position of the ovary, the overall shape of the flower, and the pattern of symmetry.
2. Which flower did you classify as a crucifer? Describe two flower characteristics you think may be useful in identifying flowers from other crucifer plants.
The mustard flower is a crucifer. The flower was not cup-shaped, and the top view of the lower showed radial symmetry with four petals arranged in a shape like a plus sign, +.
3. How do you think white cabbage butterfly larvae might identify crucifer plants?
Probably by the number of petals, in the plus sign shape.

13. Inappropriate Appropriate large greater than 60 kg short
Creating a Dichotomous Key
Question
How can you create a dichotomous key to identify organisms?
Figure A3.1 These students are using criteria to sort objects into
groups like scientists use criteria to classify species into groups.
Procedure
Part 1: Everyday Objects
1. With a partner or group, empty your kit of items onto a desk or table.
2. Use the dichotomous key to organize the objects into groups. Start
by choosing a major characteristic (e.g., metal or plastic, tubular or
nontubular) and divide the objects into two groups based on the
characteristic.
3. On the key, record the defining characteristic of each group and the
names of all the objects that belong in each group.
4. For each group, determine another characteristic that can be used to
differentiate the objects into two groups. Then repeat step 3.
5. Repeat step 4 until you have 20 groups each with a single object.
Inappropriate
Appropriate
large
greater than 60 kg
short
less than 150 cm
light coloured
red
many
10 or more
beautiful
more than 6 colours
6. Use the information recorded to create a dichotomous key. For each
step in your dichotomous key, you need to create a pair of choices that
focuses on a particular characteristic.
Suppose the first characteristic recorded on your key is “presence of
hair.” Then for the first numbered step on your dichotomous key, you
would write:
1a hair is present
1b hair is absent
7. At each characteristic such as those noted above, lead the reader to the
next step to consider on your dichotomous key. What groups does each
of the characteristics lead to? Write these groups as a step in your key
and direct readers to go to the correct step for each outcome of step 1.
Continue this process to construct the rest of your dichotomous key.
8. As you write each step on your dichotomous key, use the following
guidelines:
• avoid qualitative terms such as “large” or “many”
• use quantifiable characteristics, such as exact measurements (see
Table 1)
• ensure each step has an outcome (identification of an object or a next
step to go to) for both positive and negative responses
Table 1

14. Analyzing and Interpreting Part 1: Everyday Objects
11. Give three examples of characteristics used in the dichotomous key.
12. Based on your dichotomous key, what characteristics do all the
objects share?
Part 2: Organisms from the Kingdoms
13. Did your partner successfully use your key? Explain why or why not.
14. Why is it important to use clear terms in a dichotomous key?
15. Why should qualitative terms be avoided in creating dichotomous keys?
Skill Practice
16. List some characteristics that would be useless for a dichotomous key.
Explain your choices.
17. Why are there always two choices at each step of a dichotomous key?
Forming Conclusions
18. Is there a “right” and “wrong” dichotomous key? Justify your answer.
19. What improvements might be made to your key?

16. Attachments
BiologySource2.flv
Biological Classification Kingdoms - YouTube.flv