IB DP Biology: Command terms and keywords

IB Diploma Programme Biology (SL and HL) uses the standard IB command terms. Extended questions use levels of response marking. Precise use of biological terminology is essential—vague language loses marks.

Key command terms for Biology

Command term	What to do	Common mistake
State	Short answer	Overwriting
Define	Precise meaning	Vague definition
Describe	Detailed account of process/structure	Adding explanation
Explain	Reasons and causes; mechanisms	Only describing
Compare	Similarities and/or differences	Listing separately
Suggest	Apply to new context	Textbook recall only
Evaluate	Strengths and limitations; judgement	Description only
Discuss	Range of arguments; balanced conclusion	One-sided
Deduce	Conclusion from given information	Guessing
Outline	Brief account	Too much detail
Draw	Labelled, accurate diagram	Unlabelled or rough
Annotate	Add notes to diagram	No annotations

Biological keywords (use correctly)

Term	Use correctly	Avoid
Respiration	Release of energy from glucose	Breathing
Photosynthesis	Process; light-dependent and independent	”Making food”
Homeostasis	Maintenance of stable internal conditions	”Staying the same”
Osmosis	Water movement across membrane	Diffusion of water (be precise)
Diffusion	Net movement down concentration gradient	”Spreading out”
Active transport	Requires ATP; against gradient	Passive transport
Mitosis	Nuclear division; identical cells	Meiosis
Meiosis	Reduction division; gametes	Mitosis
Gene	Unit of heredity; codes for polypeptide	Allele
Allele	Variant of a gene	Gene
Enzyme	Biological catalyst; protein	Catalyst (add “biological”)
Denaturation	Permanent change to active site	Reversible
Ecosystem	Community + abiotic factors	Habitat
Habitat	Where an organism lives	Niche
Niche	Role of organism in ecosystem	Habitat

Tips for Biology exams

1. State—one word or short phrase; no expansion
2. Describe—structure, process, sequence; no “why”
3. Explain—mechanisms and causes; use “because”
4. Evaluate—strengths and limitations, then conclusion
5. Draw—use ruler; label clearly; show proportions
6. Past papers—check mark schemes for acceptable terminology

How Tutopiya helps

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Based on IB Diploma Programme Biology subject guide. Check the guide for syllabus-specific command terms.

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