Home › ACSEE (Form 6) › Biology › Principles of Classification › A dichotomous key identifies an organism by:
A dichotomous key identifies an organism by:
Alisting every known species in order of size
Bgrouping organisms by the colour they appear
Cbranching into three or more choices at each step
Doffering paired contrasting statements at each step
Answer & Solution
Correct answer: D. offering paired contrasting statements at each step
1. The word dichotomous means divided into two.
2. At every step the key offers exactly two contrasting statements about a feature.
3. The user picks the statement that is true of the specimen and follows it to the next numbered step.
4. Following the sequence of true statements eventually names the organism.
5. Constructing a branched key with three or more options at a step was a recorded error, and it breaks the method.
_Source: NECTA ACSEE 2023 Biology 133/1, Question 3: Principles of Classification_