Biology Year 11 - Module 3 - Lesson 4

Dichotomous Keys

Use this worksheet after reading the lesson to practise the key ideas and prove you can meet the success criteria.

Name

Date

Class

1. Key Ideas

A field biologist, forensic ecologist or teacher identifying a specimen cannot always jump straight to DNA sequencing. Dichotomous keys exist because observable features can narrow identity quickly and systematically, as long as the choices are clear and mutually exclusive.

Key facts and definitions for Dichotomous Keys
The concepts and principles underlying Dichotomous Keys

2. Success Criteria

By the end, you should be able to:

Key facts and definitions for Dichotomous Keys
Relevant terminology and conventions
The concepts and principles underlying Dichotomous Keys

3. Key Terms

long as the choicesclear and mutually exclusive

two leavesboth green and broad, is that enough information to identify the plant reliably?

dichotomous keyand how it works

keyeffective and when it breaks down

Bacterialiving cells; viruses are non-living particles that require host cells to reproduce

the keypoorly designed because the pair is not mutually exclusive

4. Activity: Build the Lesson Map

Use the lesson to complete the table. Keep answers brief but specific.

Prompt	Your answer
Main concept
Important example
Common mistake to avoid
How this links to the next lesson

5. Short Answer Questions

1. Explain this lesson goal in your own words: "Key facts and definitions for Dichotomous Keys". Use one specific example from the lesson.

Band 32 marks

2. Apply this idea to a new example: "Relevant terminology and conventions". Show your reasoning clearly.

Band 43 marks

3. Analyse why this idea matters for understanding Dichotomous Keys: "The concepts and principles underlying Dichotomous Keys".

Band 54 marks

6. Extend: Apply the Idea

Band 5/65 marks

A student gives a memorised answer about Dichotomous Keys but does not use evidence or reasoning.

Improve the answer by writing a stronger response that uses accurate terminology, a relevant example and a clear explanation.

7. Multiple Choice

1. What is the best first step when answering a question about Dichotomous Keys?

A. Identify the key concept being tested

B. Write every fact from memory

C. Ignore the command word

D. Skip examples and evidence

2. Which answer would show stronger understanding of Dichotomous Keys?

A. An answer with accurate terms and reasoning

B. A copied definition only

C. A single-word response

D. An answer with no example

3. What should you do if a question asks you to explain?

A. Link the idea to a reason or cause

B. List unrelated facts

C. Only draw a diagram

D. Write the shortest possible answer

8. Success Criteria Proof

Finish with evidence that you can do each success criterion.

Success criterion 1

Prove that you can: Key facts and definitions for Dichotomous Keys