Year 10 Science · Unit 1 · Lesson 5

Genetic Variation and Mutations

Foundation Worksheet

Name

Date

Class

Learning Goals

Match mutation types and causes to their correct definitions
Distinguish between mutation types, causes, and sources of genetic variation
Recall that mutations can be harmful, beneficial or neutral

Warm Up

Match each term to its definition

Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.

Term	Your answer	Definition
Substitution		A. A substance or factor that increases the rate of mutations in DNA
Insertion		B. The differences in DNA sequences between individuals of the same species
Deletion		C. A mutation where one base is replaced by a different base
Neutral mutation		D. A mutation that has no effect on the organism's survival or reproduction
Mutagen		E. A mutation where one or more bases are removed from the DNA sequence
Genetic variation		F. A mutation where one or more extra bases are added into the DNA sequence

Your Turn

Sort it!

Write each item from the pool into the correct category box below.

UV radiation from sunlight Independent assortment during meiosis One base replaced by another Cigarette smoke chemicals Random fertilisation Extra base inserted into sequence Crossing over during meiosis Ionising radiation (X-rays) Base removed from sequence Replication error not corrected by proofreading

Mutation type

Cause of mutation (mutagen)

Source of genetic variation (not mutation)

Show What You Know

1. Explain why insertion and deletion mutations are often more damaging to a protein than substitution mutations.

Recall 2 marks

2. Give one example of a beneficial mutation and explain why it was beneficial for the organism that carried it.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?