Create dichotomous keys lesson

Years 7 and 8

Students engage in a hands-on exploration of local diversity. They learn how to create dichotomous keys and translate their keys into a wildlife discovery app prototype.

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    Lesson Plan

    Create dichotomous keys

    Years 7 and 8

Learning Hook

  1. Ask your students, ‘how well do you know your local wildlife?’ In small groups, have students record what types of local animals (common names are fine) they have observed in the community. As a class, aggregate the observations and order them according to phyla.
  2. Lead a discussion about their observations, focusing on topics such as:
  • Are all phyla equally represented? What might explain the differences observed?
  • Do students think the number of animals they’ve identified for each phyla represents the relative size of that phyla locally?

Learning input

It would not be surprising if the class can only name a fraction of the species in the local area. Share with students that we’re often only aware of the bigger vertebrates, and even then, taxonomists are still discovering new species across Australia. In 2020, 763 new species were discovered and named in Australia, and according to Bush Blitz around three-quarters of Australia’s biodiversity is still waiting to be discovered.

Explain to students that an important activity designed to help identify new species is to go on a Bush Blitz expedition. Bush Blitz is a nature discovery program developed in a partnership between the Department of Agriculture, Water and the Environment, Parks Australia, BHP and Earthwatch Australia. Learn more about the program here.

Learning construction

Part A

Students explore the school or a local park or reserve to conduct a Bush Blitz and identify fungi, plants, insects, spiders, reptiles or mammals. Use this guide from Bush Blitz to structure the exploration.

As a class, watch this video to introduce the exploration. Each student should endeavour to observe and identify at least five species. Following the Bush Blitz, create a digital class collection of identified species.

Backyard Species Discovery – a virtual, citizen science Bush Blitz

Part B

Challenge students to create an app prototype that will help community members identify local wildlife. The app should be both functional and appealing and show consideration of both the purpose and the audience.

In order to develop the app information architecture, students will first need to develop a dichotomous key that will enable users to key out a species from the class digital collection. They can work in pairs or small groups to develop their key on paper or digitally using a presentation tool or app.

Once students have determined the structure of their key, they can design an interactive prototype using PowerPoint or Keynote by following these steps:

  1. Plan the user interface by identifying the screens a user will encounter and use arrows to show how users will move between screens. Consider how to engage the broader community to use your app.
  2. Sketch designs for each screen.
  3. Set up the dimensions of the PowerPoint or Keynote slide to match a computer, tablet or phone.
  4. Design each screen on a separate slide.
  5. Use hyperlinking to create links between slides (these will work when the presentation is played). Make sure you disable tapping anywhere to progress the presentation.
  6. Use animation tools to create interesting effects.
  7. Test the presentation on the device of choice. This is a good opportunity to collect user feedback on your design!