A dichotomous key works by

  1. listing organisms in order of size
  2. grouping organisms by where they live
  3. dividing organisms into two groups at each step using a feature
  4. naming organisms by colour only
Answer

C) dividing organisms into two groups at each step using a feature

Dichotomous means dividing into two. O Level Biology · Topic 2 Classification · 2.1 Concept and use of a classification system

Biology MCQ · More O Level Biology: Classification MCQs · Practise