Students will practice using 2 different plant classification keys to identify species.
Classroom Activity Materials:
Curriculum Extensions Materials:
Background for Teachers
When a scientist discovers a new species of plant or animal, they don't create
their own classification scheme. They will use an existing scheme which was created by
grouping plants that share the similar characteristics. In this activity, the students will
need to make choices between the similarities and differences between their object and
the classification scheme.
Intended Learning Outcomes
1. Use science process and thinking skills
Pre-Assessment/Invitation to Learn
Have the students bring one or two leaves from home. In small groups have
the students start classifying the leaves into different groups. Remind the students
that they need to look for similar characteristics. The students will need to look at
shapes of the leaves, how many leaves are on the stem and if the leaves have teeth
or lobes. The students will need to justify their classification scheme and groups.
As a class, discuss the students' classification schemes and reasoning. Discuss
that when a new species of plant is discovered scientists use existing classification
schemes. The students will be using some today. (See performance assessment at
the end of this unit to assess the students' learning.)
- Hand out the two different tree keys.
- Model the process by showing a picture of one of the trees and walking
through the choices. Remember to state the similar and different
characteristics of choices given.
- Start with the tree diagram. Model the stops and tell about the
characteristics and decisions you make.
- Look at the tree key. Explain and draw on the board each of the descriptions of
trees. Model the same tree through the different key. Make sure you write down
the steps it took to get the answer. Example 1b, 4a, 5a, 6b, 7a. (quaking aspen)
- Divide the students into small groups. Give each group a picture and a sample
leaf from the unknown tree and have the students practice determining which
tree it is. The students can record their findings on the tree worksheet.
- After five to ten minutes have the groups rotate the pictures and leaves.
- When all the groups have seen the pictures and leaves, start a class discussion
on the students' findings and processes.
- In a journal, have the students answer the following question:
Journal entry: What is the difference between existing classification schemes
and creating your own classification scheme? If you found a new species, what
scheme would you use and why should you use it?
- The previous activity can be made simpler by breaking up the two different
classification keys into a two day activity. This would give the students more
time to practice classifying the Utah trees. If you do this, you will need to
bring in more pictures and leaves of Utah trees. (ILO 1)
- For additional practice in classification have students classify Utah animals.
Homework and Family Connections
- Encourage students to check at home for any potato chips they might have to
classify with family members.
- As a family, walk around the neighborhood and pick leaves off some trees.
Classify the leaves how you want. Put them on posterboard. Go to the library to find
a book about trees. Find the leaves in the tree books and write their names under
the leaves. You can make a key if you'd like. Bring to school to share.
- An assessment for classifying leaves can be found at the end of the unit. You can use it as an assessment after the students have practiced with this activity.
- Read notes written in the students’ journals to see if understanding was accomplished.