---
title: "Genetic Mutation"
description: "Explain mutation as a change in DNA sequence that arises without regard to an organism's needs, name causes such as copying errors, radiation and some chemicals, and distinguish neutral, harmful and b"
canonical: https://lightmysky.com/learn/science/genetic-mutation-mt_rOqo-8GeKt
source: https://lightmysky.com/learn/science/genetic-mutation-mt_rOqo-8GeKt.md
retrieved: 2026-11-12
---

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# Genetic Mutation

Explain mutation as a change in DNA sequence that arises without regard to an organism's needs, name causes such as copying errors, radiation and some chemicals, and distinguish neutral, harmful and beneficial effects

Subject: Science · Area: Ecosystems & Habitats · Ages 12 to 14
Page: https://lightmysky.com/learn/science/genetic-mutation-mt_rOqo-8GeKt

## Ready when they can

- Defines mutation as a change to DNA sequence that does not arise because an organism needs it
- Names copying errors and examples of mutagens, such as UV radiation and some chemicals
- Explains that mutations create new gene versions, while mixing existing versions creates new combinations
- Explains how an inherited beneficial mutation can become more common through natural selection

## Lesson: What Is a Genetic Mutation?

Genes are sections of DNA. A mutation is a lasting change in DNA's letter sequence. Letters can be replaced, added or removed. Mutations do not arise because an organism needs them. Here, random means that a change happens without regard to whether it will help.

*(drawing: Compare the same DNA section before and after. Its fourth letter changed from G to T.)*

DNA copying errors can become mutations if they are not corrected. Mutagens increase the chance of mutations. Examples include UV radiation from sunlight and some chemicals in tobacco smoke. Cells can repair DNA damage, so damage does not always leave a mutation.

**Example.** Mutations can be neutral, harmful or beneficial for survival or reproduction. Many have no effect on either, so they are neutral. In an imagined forest, a darker-shell mutation helps beetles hide from birds. Where colour makes no difference to survival or reproduction, it is neutral.

Mutation creates new gene versions. Mixing existing versions creates new combinations without a new mutation. Natural selection can make an inherited version more common if its carriers leave more surviving offspring. Spread is not guaranteed. In humans, mutations in eggs or sperm can be passed to children; a mutation only in skin cells is not normally inherited.

**Recap.** Mutations change DNA without regard to an organism's needs. They can be neutral, harmful or beneficial. Natural selection may make an inherited helpful version more common.

*Lesson and questions written for this dataset. OpenStax and Khan Academy records were studied for scientific background.*

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Chromosomes, Genes & DNA](https://lightmysky.com/learn/science/chromosomes-genes-and-dna-mt_6aJUzBYGNs)

## Opens up

- [Mutations and Their Effect on Proteins](https://lightmysky.com/learn/science/mutations-and-their-effect-on-proteins-mt_dTOQH3vGSz)
- [How Natural Selection Works](https://lightmysky.com/learn/science/how-natural-selection-works-mt_FuVEZ1Ac9s)