Dichotomous key – classifying organisms with yes/no questions
Integrated ScienceCells & OrganismsAges 11–12
Use it with your class: students open it from a link or a QR code, with no account needed.
Next in Cells & Organisms
Students pick an organism (from 8 familiar animals or 6 familiar plants) and answer a series of yes/no questions about its features; the dichotomous key diagram on the canvas highlights the path taken until the organism is identified. Guided mode checks each answer and explains it; exploration mode lets students answer freely to see which organism the key leads to. A classification hierarchy screen places 15 example organisms from domain to species, shows the shared features narrowing at each rank, compares two organisms, lets students sort an organism rank by rank and write its binomial name, and compares the three-domain and five-kingdom systems with feature cards for kingdoms, vertebrate classes, arthropod groups and viruses. A Five-kingdom sorter screen lets students drag 30 organisms into Monera, Protista, Fungi, Plantae and Animalia using cell type, cell number, nutrition and cell wall, explains every wrong drop, and opens each kingdom's main groups with examples.
Lesson: Classification of living things: building and using a dichotomous key
What it shows
Classification sorts living things into groups. A dichotomous key identifies an organism through paired yes/no questions; this simulation has an animal key and a plant key. Linnaeus arranged organisms in ranks from kingdom to species, and each species has a two-part binomial name such as Panthera leo. The five-kingdom system groups organisms by cell type, cell number, nutrition and cell wall: Monera, Protista, Fungi, Plantae and Animalia, which the sorter lets you practise. The three-domain system, based on ribosomal RNA, splits prokaryotes into Bacteria and Archaea.
How to use
In Dichotomous key, pick an organism and answer each question with Yes or No. In Classification hierarchy, choose an organism to explore its ranks, Compare with another, or Sort it yourself and write its binomial name. In Five-kingdom sorter, drag each card into a kingdom or tap a kingdom; untick Show features for a harder round, press New deck to start again, and open the kingdom tabs to see the groups.
Parameters you can change
- Organism set 8 animals, 6 plants
- Mode Guided (pick an organism, checked step by step), Exploration (answer freely)
- Show dichotomous key diagram
- Randomly pick an organism at start
- Screen Dichotomous key, Classification hierarchy, Five-kingdom sorter
- Classification system Three domains, Five kingdoms
Questions to explore
- Why does every step in a dichotomous key offer exactly two choices?
- Would a question about size, such as big or small, work well in a key? Why?
- Which new yes/no question could separate the rabbit from the frog?
