Biology A-Level
relatedness
What relatedness means in Biology A-Level, as defined for AQA.
Definitions of relatedness
Exam boards and our study guides word this term in slightly different ways. Learn the version your board uses.
Check what you remember
Read the wording for your board, then hide it and explain relatedness in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
The fewer the differences in base or amino acid sequences, the more recently the organisms shared a common ancestor and the more closely related they are.
Organisms sharing a small group also share a recent common ancestor, and sharing a genus would make them more closely related still.
Topics that use relatedness
- Investigating diversity (AQA A-Level)
- Species and taxonomy (AQA A-Level)
Related terms
- amino acid sequence comparison
- biological species concept
- classification tables
- common names
- convergent similarity
- direct DNA investigation
- domain to species
- eight taxonomic levels
Using relatedness 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