Six-mark questions
Six-mark questions are extended open response questions. These require longer answers than the structured questions with fewer marks. It is wise to plan your answer rather than rushing straight into it, otherwise you may stray away from the key points.
Six-mark questions are marked using a levels-based mark scheme because they are open ended. To gain full marks, you need to:
- support explanations using scientific knowledge and understanding
- use appropriate scientific words and terms
- write clearly, linking ideas in a logical way
- maintain a sustained line of reasoning, rather than getting lost or bogged down
You are likely to see command words such as:
- 'describe' - you need to give an account but no reason
- 'explain' - you must give reasons or explanations
- 'devise' - you must plan or invent a procedure using your scientific knowledge and understanding
- 'evaluate' - you must review information, including identifying strengths and weaknesses, and make a supported conclusion
Six-mark questions may be synoptic questions. These questions bring together ideas from two or more topics. For example, a question about atoms could include ideas about atomic structure, isotopes, radiation and nuclear reactions.
Remember that the topics covered in the first paper are assumed knowledge for the second paper, so questions in the second paper may need knowledge and understanding of those topics too.
The answers shown here give marking points as bullet points. You do not usually need to include all of them to gain six marks, but you do need to write in full sentences, linking them logically and clearly.
Writing six-mark answers with Dr Alex Lathbridge
Listen to the full series on BBC Sounds.
How to write six-mark answers in your science GCSE exams.
Sample question 1 - Foundation
Question
Arnav collects two sets of information about sound and ultrasound.
One is a table and the other is a diagram.
| Wave | Type of wave | Uses |
| Sound | Longitudinal | Talking to each other, listening to blood flow, listening to music |
| Ultrasound | Transverse | Breaking down kidney stones, measuring blood flow, X-ray of bones, cooking food |
| Wave | Sound |
|---|---|
| Type of wave | Longitudinal |
| Uses | Talking to each other, listening to blood flow, listening to music |
| Wave | Ultrasound |
|---|---|
| Type of wave | Transverse |
| Uses | Breaking down kidney stones, measuring blood flow, X-ray of bones, cooking food |
Describe and explain what is wrong in the table and the diagram. [6 marks]
OCR Gateway Science, GCE Physics, Paper B752, June 2015.
The labels for rarefaction and compression are the wrong way round. Compression is where the particles are more concentrated. Longitudinal waves change gradually and do not have bands.
A number of things are wrong in the table: ultrasound is not a transverse wave, sound is not used to measure blood flow, ultrasound is not used for X-ray of bones and ultrasound is not used to cook food. Ultrasound is a longitudinal wave and is used to measure blood flow, X-rays are used to X-ray bones, and microwaves and infrared are used to cook food.
Answering tip: Briefly plan the key points you want to include in your answer. For example:
- errors in diagram - look at the labels
- errors in table - check type of wave and uses
- explain the errors
Sample question 2 - Higher
Question
Chantal does some experiments using light.
She shines a beam of white light through a prism.
Look at the diagram.
The white light disperses to produce a visible spectrum of colours.
Explain why the white light disperses, and why the colours deviate by different amounts. [6 marks]
OCR Gateway Science, GCE Physics, Paper B752, June 2015 - Higher.
The dispersion of light suggests that light slows down when entering the glass. Different colours have different speed changes, refractive indexes, frequencies and wavelengths.
The colour deviation suggests that violet light slows down most and has a higher frequency and a shorter wavelength. Violet light also has the highest refractive index and highest frequency.
Answering tip: Briefly plan the key points you want to include in your answer. For example:
- speed of light in air and glass
- differences between colours - mention refractive index
- why violet changes direction the most
Sample question 3 - Higher
Question
Ultrasound can be used on humans.
Becky has her body fat measured using ultrasound on her arm. The diagram shows the output from the ultrasound probe.
Ultrasound reflects strongly at different layers inside the arm.
The body fat layer is just below the skin.
The different tissue layers in the arm are:
- fat-muscle layer
- muscle-muscle layer
- muscle-bone layer
Why is ultrasound used rather than surgery or X-rays to measure body fat?
Explain what the probe's output shows, and how it can be used to find the thickness of body fat in Becky's arm. [6 marks]
OCR Gateway Science, GCE Physics, Paper B752, June 2015 - Higher.
Ultrasound is used instead of surgery because it is non-invasive and does not cause damage to people or leave any scars. Ultrasound is quick and accurate and can be used to measure fat thickness in different parts of the body.
Ultrasound is used instead of X-rays because it can produce images of soft tissue and does not damage living cells.
In the diagram, each peak is at a tissue boundary. Waves reflect from tissue boundary - the first peak shows the thickness of body fat. The other peaks show reflections at different depths/distances. For example, peaks A, B and C are at different depths in the body. Peak A is at 5 to 7 mm, where the ultrasound is reflected at the fat-muscle layer. So the thickness of fat in the arm is 5 to 7 mm.
Answering tip: Briefly plan the key points you want to include in your answer. For example:
- advantages of ultrasound vs surgery/X-rays
- reflection of waves at boundaries
- work out which layer is fat-muscle and give depth
