Understand exactly what examiners want when they use specific command words
Command words tell you what type of answer the examiner wants. Using the wrong approach loses marks even if your knowledge is correct. A "describe" answer won't get full marks on an "explain" question.
Critical: Many students lose marks not because they don't know the content, but because they don't answer in the way the command word requires.
These command words ask you to remember and write down facts from your knowledge.
What it means: Give a short, simple answer with no explanation needed.
What to do: Write a brief fact, name, or term - usually one word or short phrase.
State the chemical symbol for sodium.
Na
Sodium is represented by Na because it comes from the Latin word natrium.
Too much information - "state" only needs the fact.
What it means: Give the correct name or label for something.
What to do: Provide a specific term, name, or label from your studies.
Identify the process by which plants make food.
Photosynthesis
What it means: Write a number of brief points with no detail.
What to do: Give several short answers, usually as bullet points or numbered list.
List three renewable energy sources. [3 marks]
1. Solar energy
2. Wind energy
3. Hydroelectric energy
Solar energy is renewable because the sun will keep shining for billions of years and we can use solar panels to convert sunlight into electricity.
Too much explanation - "list" only needs the names.
What it means: Give the precise meaning of a term.
What to do: Write a clear, accurate definition - be specific and use scientific language.
Define the term "ecosystem". [2 marks]
A community of living organisms interacting with each other and their physical environment.
It's like when animals and plants live together somewhere.
Too vague and informal - needs scientific precision.
These command words ask you to show you understand concepts by describing or explaining them.
What it means: Give the key features or characteristics of something.
What to do: Write WHAT happens, but not WHY. Include observations and details.
Describe what happens during photosynthesis. [3 marks]
Carbon dioxide and water are taken in by the plant. Light energy is absorbed by chlorophyll. Glucose and oxygen are produced.
Plants need photosynthesis because it allows them to survive by making their own food, which is important for their growth.
This explains WHY photosynthesis happens, not WHAT happens.
Key Point: Describe = What you see or what happens. No reasons needed.
What it means: Give reasons WHY something happens or HOW something works.
What to do: Make a clear statement, then give the reason using words like "because", "so", "therefore".
Explain why metals conduct electricity. [3 marks]
Metals contain free electrons that are not attached to any particular atom. These free electrons can move through the metal structure. When a voltage is applied, the electrons flow, creating an electric current.
Metals have free electrons that can move.
This describes the situation but doesn't explain WHY this allows conduction.
Pro Tip: For every mark, try to include a statement + reason. Use linking words: because, so, therefore, this means that, as a result.
What it means: Give the main points without going into too much detail.
What to do: Provide a brief summary of the key features or steps.
Outline the stages of mitosis. [3 marks]
Chromosomes condense and become visible. They line up at the cell equator. The chromosomes separate and move to opposite poles of the cell.
What it means: Apply your knowledge to a new situation - there may be more than one correct answer.
What to do: Make a reasonable proposal based on your scientific understanding.
Suggest why desert plants have thick, waxy leaves. [2 marks]
The thick, waxy coating reduces water loss through evaporation. This is an adaptation to survive in the dry desert environment.
Note: "Suggest" questions test if you can apply your knowledge to unfamiliar situations. Use scientific reasoning.
These command words ask you to use your knowledge in practical ways.
What it means: Prove something is true by working through the steps or logic.
What to do: Provide clear working and logical steps that lead to the conclusion.
Show that the acceleration of the object is 5 m/s². [2 marks]
a = (v - u) / t
a = (20 - 0) / 4
a = 5 m/s²
What it means: Draw a simple diagram showing the key features.
What to do: Create a clear, labeled drawing - doesn't need to be artistic, but must be accurate.
Sketch a graph showing how the speed of an object changes with time when it accelerates uniformly from rest. [2 marks]
A straight line starting from origin (0,0) sloping upward. Axes labeled "Speed" (y-axis) and "Time" (x-axis).
Remember: Always label axes on graphs and key parts on diagrams. Use a ruler for straight lines.
What it means: Fill in missing information in a sentence, table, or diagram.
What to do: Add the correct word, number, or label to finish the task.
Complete the word equation: magnesium + oxygen → _____
magnesium oxide
These higher-level command words ask you to examine, judge, or make decisions about information.
What it means: Break down information into parts and examine relationships or patterns.
What to do: Identify key points, show connections, and explain significance.
Analyse the data in the table to explain the trend in population growth. [4 marks]
The population increased from 100 to 500 between years 1-3, showing exponential growth. After year 3, growth slowed to reach 600 by year 5, suggesting the population approached carrying capacity. This pattern is typical when resources become limited.
What it means: Judge the importance or quality of something, considering both sides.
What to do: Present advantages and disadvantages, then reach a reasoned conclusion.
Evaluate the use of nuclear power as an energy source. [6 marks]
Advantages: Nuclear power produces large amounts of energy from
small amounts of fuel with no CO₂ emissions during operation, helping combat
climate change. It provides reliable baseload electricity regardless of
weather.
Disadvantages: Nuclear waste remains radioactive for thousands
of years requiring expensive long-term storage. There is a risk of catastrophic
accidents as seen at Chernobyl and Fukushima. Initial construction costs are
very high.
Conclusion: While nuclear power offers a low-carbon energy
option, the high risks and costs suggest it should be part of a mixed energy
strategy rather than the sole solution.
Structure for Evaluate: Point 1 (advantage) + explain → Point 2 (disadvantage) + explain → Balanced conclusion
What it means: Give good reasons to support a decision or statement.
What to do: Explain why your answer or choice is correct with clear reasoning.
Justify why copper is used for electrical wiring. [3 marks]
Copper is an excellent conductor of electricity due to its free electrons. It is ductile so can be drawn into thin wires. It is also relatively cheap and abundant compared to alternatives like silver.
What it means: Present multiple viewpoints or aspects of a topic in detail.
What to do: Explore different perspectives, evidence, or arguments without necessarily reaching a conclusion.
Discuss the impacts of deforestation. [6 marks]
Deforestation has multiple environmental impacts. It reduces biodiversity as
habitats are destroyed, threatening species with extinction. Loss of trees
decreases CO₂ absorption, contributing to climate change. Soil erosion increases
without tree roots to hold soil in place, leading to reduced fertility and
increased flooding.
Economic impacts include loss of potential medicines from undiscovered species
and reduced income for indigenous communities. However, deforestation can
provide short-term economic benefits through timber sales and land for
agriculture, though these are often unsustainable.
These command words require mathematical working.
What it means: Work out a numerical answer using mathematical operations.
What to do: Show your working, include units, give answer to appropriate significant figures.
Calculate the speed of a car that travels 150 m in 10 s. [3 marks]
speed = distance / time
speed = 150 / 10
speed = 15 m/s
15
No working shown, no units - may only get 1 mark instead of 3.
Always remember: Formula → Substitution → Working → Answer with units
What it means: Find the answer using data, graphs, or calculations.
What to do: May involve reading from a graph, measuring, or calculating - show your method.
Determine the gradient of the line on the graph. [2 marks]
gradient = rise / run
gradient = 40 / 8 = 5
What it means: Find an approximate value - exact precision not required.
What to do: Round numbers to make calculation easier, show your method.
Estimate the answer to 48.7 × 9.3
50 × 10 = 500
These command words relate to practical and experimental work.
What it means: Design an experiment or investigation.
What to do: Include variables, method, equipment, safety, and how to make it fair.
Plan an investigation to find out how temperature affects the rate of enzyme activity. [6 marks]
Variables: Independent - temperature; Dependent - time for
reaction; Control - enzyme concentration, pH, substrate concentration
Method: Set up water baths at 20°C, 30°C, 40°C, 50°C, 60°C. Add
enzyme to substrate and time how long reaction takes.
Fair test: Use same volumes, same enzyme concentration, repeat
three times and calculate mean.
Safety: Wear goggles, be careful with hot water baths.
What it means: Find the size or amount of something using equipment.
What to do: Use appropriate measuring equipment and record with correct units and precision.
Measure the length of the line.
7.4 cm
What it means: Say what you think will happen based on scientific knowledge.
What to do: Use patterns, trends, or scientific principles to forecast an outcome.
Predict what will happen to the rate of reaction if the temperature is increased from 30°C to 50°C. [2 marks]
The rate of reaction will increase because particles have more kinetic energy and collide more frequently with greater energy.
These command words ask you to look at similarities and differences.
What it means: Identify similarities and differences between two or more things.
What to do: Make direct comparisons - use comparative words like "whereas", "but", "while".
Compare plant and animal cells. [4 marks]
Both plant and animal cells have a nucleus, cytoplasm, and cell membrane. However, plant cells have a cell wall whereas animal cells do not. Plant cells contain chloroplasts for photosynthesis while animal cells do not. Plant cells have a large permanent vacuole but animal cells have small temporary vacuoles.
Plant cells have a cell wall and chloroplasts. Animal cells have a nucleus and cytoplasm.
This describes each separately but doesn't compare them directly.
Comparison Structure: Both have X. However, A has Y whereas B has Z. A does this while B does that.
What it means: Explain the key differences between two things.
What to do: Focus on what makes them different from each other.
Distinguish between speed and velocity. [2 marks]
Speed is a scalar quantity measuring only how fast something moves. Velocity is a vector quantity that includes both speed and direction of motion.
If the question says "describe", don't give reasons. Save explanations for "explain" questions.
"Explain" needs reasoning and detail. One short sentence usually isn't enough.
"Evaluate" requires both advantages and disadvantages - you need balance.
Always show your working - you can still get method marks if your answer is wrong.
Calculations need units. "15" is wrong, "15 m/s" is correct.
"Compare" means make direct links, not describe each thing separately.
Top Tip: Read the command word twice before you start writing. Check you're answering in the right way.
| Command Word | What to Include | Don't Include |
|---|---|---|
| State | The fact only | Explanations |
| Describe | What happens | Why it happens |
| Explain | Reasons and causes | Just descriptions |
| Calculate | Working + units | Just the answer |
| Evaluate | Both sides + conclusion | One-sided argument |
| Compare | Direct comparisons | Separate descriptions |
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