Biology Year 12 - Module 6 - Lesson 6

Fertilisation, Meiosis and Mutation as Causes of Genetic Variation

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

Siblings can be genetically different even when no new mutation occurs, because meiosis reshuffles parental alleles and fertilisation combines gametes randomly. Mutation plays a different role: it introduces genuinely new alleles into the population. This lesson brings those sources of variation together and keeps their jobs separate.

  • Mutation, meiosis and fertilisation all contribute to variation.
  • These processes have different roles, not interchangeable roles.

2. Success Criteria

By the end, you should be able to:

  • Mutation, meiosis and fertilisation all contribute to variation.
  • Mutation creates new alleles.
  • Meiosis and fertilisation mainly reshuffle existing alleles.

3. Key Terms

Genetic variationDifferences in genetic makeup between individuals in a population.
MutationA change in DNA sequence that can create a new allele.
MeiosisCell division that produces haploid gametes and reshuffles alleles through independent assortment and crossing over.
FertilisationFusion of two gametes, combining alleles from each parent in a new offspring.
Independent assortmentRandom separation of homologous chromosomes during meiosis.
Gene poolThe total collection of alleles in a population.

4. Activity: Build the Lesson Map

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

PromptYour 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: "Mutation, meiosis and fertilisation all contribute to variation.". Use one specific example from the lesson.

Band 32 marks

2. Apply this idea to a new example: "Mutation creates new alleles.". Show your reasoning clearly.

Band 43 marks

3. Analyse why this idea matters for understanding Fertilisation, Meiosis and Mutation as Causes of Genetic Variation: "Meiosis and fertilisation mainly reshuffle existing alleles.".

Band 54 marks

6. Extend: Apply the Idea

Band 5/65 marks

A student gives a memorised answer about Fertilisation, Meiosis and Mutation as Causes of Genetic Variation 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 Fertilisation, Meiosis and Mutation as Causes of Genetic Variation?

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 Fertilisation, Meiosis and Mutation as Causes of Genetic Variation?

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: Mutation, meiosis and fertilisation all contribute to variation.

Band 32 marks
Success criterion 2

Prove that you can: Mutation creates new alleles.

Band 43 marks
Success criterion 3

Prove that you can: Meiosis and fertilisation mainly reshuffle existing alleles.

Band 54 marks

One thing I still need help with: