Teaching sequence

Lesson objective

In this lesson students understand the use of classification keys and use and develop their own classification keys for a variety of objects.

Introduction

Show students the images of the European magpieand the Australian magpie.

European Magpie

Source: Wikimedia Commons, European magpie photo by Pete Birkinshaw, CC BY 2.0

Magpie

Source: Flickr, Magpie , OZinOH, CC BY-NC 2.0

Ask the students to identify the characteristics these birds have in common and the characteristics that are unique.

Core

1. Suggest to the students that scientists need an organised way to identify individual organisms. Ask students how a supermarket or department store organise their products so that shoppers can find them.
2. Can students do this to the items in their pencil case? Complete the worksheet Pencil case classification (Word. 403 KB). Discuss how easy this key was to use and if there was any difficulty in classifying objects (eg glue and sticky tape).
3. Suggest that scientists can use such keys to identify the names of living organisms. Complete the worksheet Bookworm who? (PDF, 455 KB) and check student responses.
4. Watch the video clip Understanding classification using a dichotomous key. Ask students who makes up such keys for classification.
5. Complete the worksheet Card tricks (PDF, 353 KB) and discuss student responses.
6. Ask students to make their own key to identify members of their class to a new student.
7. Complete the worksheet Who am I? (Word, 389 KB) This activity can be completed on paper or alternatively it allows an opportunity to extend computer skills by using a spreadsheet to gather data and for the data to be sorted. Other mind-mapping programs can be used to construct a key. If appropriate, students can allocate a nickname to class members for the teacher to determine who has what nickname.

Conclusion

Ask students to think about how they could classify members of their family (including pets) or items in their bedroom. What characteristics do they have in common? What characteristics do they have the same? Ask what characteristics would they look for in plants or animals?