How to Make a Dichotomous Key for Animals

Making a Dichotomus Key for Animals

• 1

  Identify the key attributes for animals: multicellular, heterotrophic and lack of cell walls.

• 2

  Create the first branch of the dichotomous key: unicellular versus multicellular. If the organism is unicellular, it cannot be an animal. Instead, it must be a bacteria or a protist.

• 3

  Write the second branch of the dichotomous key: heterotrophic versus autotrophic. Heterotrophic organisms consume other organisms, while autotrophic organisms make their own food via photosynthesis. An animal is heterotrophic. This step of the key eliminates organisms in the Plantae Kingdom.

• 4

  Draw the third branch of the dichotomous key: cell wall versus no cell wall. The only types of organisms that have not been eliminated at this step are fungi and animals; fungi have cell walls (an extra layer of protection around the cell's membrane), while animals do not.