# Distinguish between analogous structures and homologous structures, using one named example of each to support your answer.

> IB DP Biology Higher Level (2023 syllabus) — A3.1 Diversity of organisms · Distinguish · 4 marks

## Mark scheme (4 marks)

1. Homologous structures share a common evolutionary origin / are derived from the same ancestral structure, even if they differ in function.
2. Analogous structures perform a similar function but do not share a common evolutionary origin / arose independently through convergent evolution.
3. A named, correct example of homologous structures, e.g. the pentadactyl limb found in humans (arm), whales (flipper), and bats (wing) — same underlying bone arrangement but different functions.
4. A named, correct example of analogous structures, e.g. the wings of a bird and an insect — both used for flight but evolved independently with no common structural ancestry.

## Key terms

- [analogous structures](https://www.gradenine.co.uk/glossary/analogous-structures)
- [homologous structures](https://www.gradenine.co.uk/glossary/homologous-structures)

## Related

- [Revision notes for IB DP Biology Higher Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Distinguish" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/distinguish-between-analogous-structures-and-homologous-da221d1e) · Published by Druglandscape Ltd.