Six-mark questions
Six-mark questions will only appear in the Depth paper. There will be two six-mark questions in the Depth paper.
Six-mark questions are extended free-response questions, requiring the longest answers. It is wise to plan your answer rather than rushing straight into it. Without a plan it is easy to stray away from the key point and lose marks, get steps in a process in the wrong order or forget key bits of information.
To gain six marks, you will need to:
- use appropriate scientific words and terms
- write your answer in full sentences, not bullet points
- write clearly, linking ideas in a logical way
- maintain a sustained line of reasoning, rather than a random list of statements and sentences
- support explanations using scientific knowledge and understanding
Six-mark questions are marked using a levels-based mark scheme. An answer that is not clear and logically sequenced, and which does not give a coherent argument supported by evidence, will be limited to the lower levels. Similarly, if the question asks you to discuss both sides of an argument, or explain two observations, you will be limited to the lowest level if your answer only considers one of them (no matter how brilliantly written or comprehensively explained that one is).
These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.
Sample question 1 - Foundation
Question
Compare aerobic and anaerobic respiration, including the reactants, products and energy output of each process. [6 marks]
This question will be marked in pairs of points. You are asked to compare the two types of respiration so each point you make must be a comparison.
For one correct comparison you will earn two marks, for two correct comparisons you will earn four marks and for three or more correct comparisons you will earn six marks. You must make comparisons between the reactants, products and energy output of each process as stated in the question.
- Aerobic respiration occurs in the presence of oxygen, BUT anaerobic respiration occurs without oxygen. [2 marks]
- Aerobic respiration produces lots of ATP, BUT anaerobic respiration produces a small amount of ATP. [2 marks]
- Aerobic respiration produces water and carbon dioxide, BUT anaerobic respiration produces lactic acid in animal cells, ethanol and carbon dioxide in yeast. [2 marks]
The last point can be written in the form of equations as long as each equation is clearly labelled as aerobic or anaerobic respiration.
- Aerobic reparation: Glucose + oxygen → carbon dioxide + water [1 mark]
- Anaerobic respiration (yeast): Glucose → carbon dioxide + ethanol [1 mark]
- Anaerobic respiration (animal cells): Glucose → lactic acid [1 mark]
Sample question 2 - Foundation
Question
Explain how technological developments in microscopes have helped us to understand more about aerobic respiration. [6 marks]
Some points to include are:
- cells are too small to see with the naked eye
- light microscopes help us to see cells and features of cells that are very small
- electron microscope was developed after the light microscope
- higher magnification than light microscopes
- higher resolution than light microscopes
- can see much more detail inside of cells (sub-cellular structure)
- can see mitochondria structure in more detail
- mitochondria are the organelles that carry out aerobic respiration
- scientists can develop explanations of how the structure of mitochondria relates to their role in aerobic respiration
Sample question 3 - Higher
Question
Discuss the potential benefits, risks and ethical issues associated with the use of stem cells in medicine. [6 marks]
Possible points to include:
Benefits
- Stem cells can grow into any form of tissue so they could be used to replace damaged tissues or cells.
- If a person's own stem cells are used then the body will not reject the stem cells or any tissues grown from them, unlike if they had an organ transplant from another person.
Risks
- The success of stem cell treatments is not fully understood and so the patient might not get any better.
- Mutations in stem cells that could cause cancer or viruses that have infected the stem cells, could be passed on to the patient.
Ethical concerns
- If embryonic stem cells are used then the embryo has to be destroyed to obtain the cells. Some people view this as a loss of life. Other people see it as vital to help people that are suffering.
- The full risks of stem cell therapies are not all known and so more research needs to be done to determine any side effects.
