Mutations - Edexcel IGCSE

**TES: Understanding the Impact of Mutations on Phenotype
**Objectives:

3.35B: Understand how a change in DNA can affect the phenotype by altering the sequence of amino acids in a protein.
3.36B: Understand how most genetic mutations have no effect on the phenotype, some have a small effect, and rarely do they have a significant effect.
3.37B: Understand that the incidence of mutations can be increased by exposure to ionizing radiation (e.g., gamma rays, x-rays, ultraviolet rays) and some chemical mutagens (e.g., chemicals in tobacco).

**Lesson 1: Introduction to Genetics and Mutations
*** Introduce the concept of genetics and how genes control the traits and characteristics of living organisms.

• Explain that mutations are rare, random changes in genetic material that can be inherited.
• Give examples of different types of mutations, such as point mutations, deletions, and insertions.
• Discuss how mutations can occur naturally or be caused by environmental factors, such as ionizing radiation and chemical mutagens.

**Lesson 2: DNA, Proteins, and the Impact of Mutations
*** Review the concept of DNA and how it codes for the production of proteins.

• Explain that a change in DNA can affect the phenotype by altering the sequence of amino acids in a protein.
• Use examples to demonstrate how a change in a single amino acid can have significant effects on the function of a protein.
• Discuss how most genetic mutations have no effect on the phenotype, but some can have small or significant effects.

Lesson 3: The Incidence and Consequences of Mutations
*** Review the concept of mutations and how they can affect the phenotype.

• Discuss the ways in which the incidence of mutations can be increased, such as exposure to ionizing radiation and chemical mutagens.
• Explore the potential consequences of genetic mutations, including the role they play in evolution and the potential for harmful effects on health.
• Use case studies or real-world examples to illustrate the importance of understanding mutations and their potential impacts.