Edexcel International A-level Biology: Command words and keywords

Pearson Edexcel International A-level Biology uses the command words defined in the specification. Mark schemes reward syllabus terminology and correct response to command words. Extended questions use levels-based marking.

Command words

Command word	What to do	Common mistake
State / Name / Give	Recall; short answer	Overwriting
Identify	Choose from information given	Adding explanation
Define	Precise biological meaning	Vague
Describe	What/how; no “why”	Adding explanation
Explain	Why/how; use “because”	Only describing
Suggest	Apply to new context	Textbook recall
Compare	Similarities and differences	Listing separately
Evaluate	Judge; conclude with evidence	No conclusion
Assess	Judge importance; conclude	Description only
Discuss	Explore aspects; conclude	One-sided
Calculate	Work out; show working; units	Missing working
Draw / Label	Diagram; accurate labels	Inaccurate

Keywords examiners look for

Cells and molecules

Term	Use correctly	Avoid
Mitochondrion	Aerobic respiration	Ribosome
ATP	Energy currency	”Energy”
Substrate	Molecule enzyme acts on	”Chemical”
Active site	Substrate binding region	”Slot”
Osmosis	Water; partially permeable	Including solutes
Active transport	Against gradient; energy	Without membrane
Transcription	DNA → mRNA	Translation
Translation	mRNA → protein	Transcription
Allele	Form of a gene	Gene
Genotype	Genetic makeup	Phenotype
Phenotype	Observable characteristic	Genotype

Genetics and evolution

Term	Use correctly	Avoid
Linkage	Genes on same chromosome	”Together”
Natural selection	Differential survival	”Evolution”
Selection pressure	Factor favouring alleles	”Pressure”
Speciation	New species formation	”Evolution”

Practical

Term	Use correctly	Avoid
Independent variable	What you change	”Input”
Dependent variable	What you measure	”Output”
Control variable	Kept constant	”Control”
Reliability	Repeatability	Accuracy
Validity	Fair test	Reliability

Tips for Edexcel A-level Biology

1. Underline the command word before answering
2. Explain—cause–effect; structure–function
3. Suggest—apply to the specific scenario
4. Use syllabus terms—check the mark scheme
5. Past papers + mark schemes show acceptable wording

How Tutopiya helps

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Based on Pearson Edexcel International A-level Biology specification. Check the latest specification for your exam series.