Biology A-Level
substitution
What substitution means in Biology A-Level, as defined for AQA.
Definition of substitution
Check what you remember
Read the wording for your board, then hide it and explain substitution in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
A change that replaces one base with another and therefore alters exactly one triplet, with every triplet before and after it unchanged.
Topics that use substitution
- Alteration of the sequence of bases in DNA can alter the (AQA A-Level)
Related terms
- amino acid sequence
- base analogues
- codons and anticodons
- DNA replication errors
- downstream codons
- frameshift
- premature stop codon
- R group interactions
Using substitution in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Biology questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
Start free
All Biology A-Level termsA week of Premium from your first lesson · Then the free plan continues · No card, no charge