Outline the characteristics that are used to place an organism into the kingdom Animalia, and identify one kingdom whose members share at least one of these characteristics.

IB DP Biology Standard Level (2023 syllabus) — A3.1 Diversity of organisms · Outline · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

1. Multicellular – composed of many cells
2. Eukaryotic – cells contain a membrane‑bound nucleus
3. Heterotrophic – obtain organic nutrients by ingestion, cannot photosynthesise
4. Kingdom Protista – shares the eukaryotic characteristic with Animalia

Examiner tips

Use the exact terms ‘multicellular’, ‘eukaryotic’, ‘heterotrophic’; list each as a separate point to show full marks
Give a clear justification for the chosen kingdom – e.g. Protista are eukaryotic

Common mistakes

Writing ‘cellular’ instead of ‘multicellular’; omitting the word ‘heterotrophic’; choosing a kingdom that does not share any of the listed traits

Mark scheme (4 marks)

Animals are multicellular / composed of many cells
Animals are eukaryotic / cells contain a membrane-bound nucleus
Animals are heterotrophic / obtain organic nutrients by ingestion / cannot photosynthesise
Identification of one kingdom that shares at least one characteristic with Animalia, with a valid justification — e.g. Fungi (eukaryotic and multicellular / heterotrophic); Plantae (eukaryotic and multicellular); Protista (eukaryotic)

Key terms in this question

kingdom Animalia · kingdom