Six-mark questions
Six-mark questions are often the questions that people find the most difficult. In all longer answer questions, but especially the six mark ones, it is important that you plan your answer and do not just rush into it. After all, you would plan an essay or short story before starting. 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. Remember to write your answer in full sentences, not bullet points.
Six-mark questions will start with command words such as 'describe', 'evaluate' or 'explain'.
Some command words are easy to understand such as:
- 'calculate' or 'determine' for maths questions
- 'choose' for multiple-choice questions
- 'complete' to fill in a gap in a table or graph
- 'define' to give the meaning of an important word
- 'suggest' where you use your knowledge in an unfamiliar situation
The command words 'describe' and 'explain' can be confusing. If you are asked to describe a graph, you will be expected to write about its overall shape, whether it is linear or curved, the slope of gradients etc. If you are asked to explain why a pattern or trend is seen in a graph, you will be expected to use your science knowledge not just say what you see (which is a description), eg The graph shows the pH of milk decreases. It does this because…
Explain how and why questions often have the word 'because' in their answer. Describe questions don't.
The number of marks per question part is given in this form ‘[6 marks]'. It is essential that you give as many different points in your answer as possible.
The examiner looks for a 'level of response' in six-mark questions. If you list some simple statements without a logical structure you will be limited to a maximum of two marks. A better answer for four marks would demonstrate your understanding, but may miss some details. Only answers that have a logical sequence with relevant detail would achieve six marks.
Sample question 1 - Foundation
Question
Cystic fibrosis is caused by a recessive allele (f). Huntington’s disease and cystic fibrosis are caused by a dominant allele (H). Explain what is meant by the terms allele, recessive and dominant, homozygous and heterozygous, and genotype. Link your explanations to the inheritance of cystic fibrosis and Huntington’s disease.
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
This question has many parts to it. You need to keep track of what you have included in your answer so that you don’t miss anything out. If you don’t answer all parts of the question then you can’t get top marks!
Level 3 (5-6 marks)
A well-structured, detailed description of how Huntington's disease and cystic fibrosis are inherited using the terms and their correct definitions.
Level 2 (3-4 marks)
A description of how Huntington's disease is inherited. All terms are correctly explained.
Level 2 (1-2 marks)
An attempt at describing how Huntington's disease cystic fibrosis are inherited, although some information may be missing. Some terms are used correctly.
0 marks
No response or no response worthy of credit
The following is a list of valid points that should be included in your answer:
- an allele is a version of a gene
- the genotype is the combination of alleles that you inherit
- the characteristic associated with a recessive allele will only be seen in an organism if the organism has two copies of the recessive allele
- therefore to have cystic fibrosis you must inherit two copies of the recessive allele
- if you have two copies of the same allele you are homozygous
- you would have the genotype ff
- the characteristic associated with a dominant allele will always be seen if the dominant allele has been inherited
- therefore, to have Huntington's disease you would only need to inherit one copy of the dominant allele from one of your parents
- if you have two different alleles then you are heterozygous. For Huntington’s disease this would mean you have the genotype Hh
Sample question 2 - Foundation
Question
Discuss the advantages and disadvantages of both sexual and asexual reproduction.
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
Level 3 (5-6 marks)
Several points about both sexual and asexual reproduction with clear explanations of how they are advantages or disadvantages.
Level 2 (1-2 marks)
Some advantages and disadvantages of sexual or asexual reproduction. The two methods are not compared sufficiently.
0 marks
No response or no response worthy of credit.
The following is a list of valid points that could be included in your answer. Remember that it is important that you do not bullet point them, but link your ideas together.
The advantages of sexual reproduction:
- Produces genetic variation in the offspring
- The species can adapt to new environments due to variation, which gives them a survival advantage
- A disease is less likely to affect all the individuals in a population
The disadvantages of sexual reproduction:
- time and energy are needed to find a mate
- it is not possible for an isolated individual to reproduce
The advantages of asexual reproduction include:
- the population can increase rapidly when the conditions are favourable
- only one parent is needed
- it is more time and energy efficient as you don’t need a mate
- it is faster than sexual reproduction
The disadvantages of asexual reproduction include:
- it does not lead to genetic variation in a population
- the species may only be suited to one habitat
- disease may affect all the individuals in a population
Sample question 3 - Higher
Question
Scientists have been studying an area of Mexico that is covered with black rocks. Most of the rocks in other areas are grey. The black rocks were formed about 1,000 years ago when a volcano erupted. They found that most of the mice that lived on this rock were black in colour.
Explain how the population of mice in this area became mostly black, but in other areas there are many more grey mice.
OCR Gateway, GCE Biology, Paper J247 - Higher, 2016.
You will need to talk about BOTH black and grey mice in your answer to this question, you should include WHY there are different populations of mice because the question says ‘explain how’.
Level 3 (5-6 marks)
Discusses the populations of both black and grey mice and explains the differences using relevant ideas about natural selection.
Level 2 (3-4 marks)
Discusses the populations of both black and grey mice and explains the differences. Shows a reasonable understanding of the mechanisms behind natural selection.
Level 2 (1-2 marks)
Some attempt at explaining the populations of black and grey mice. Some information may be missing.
0 marks
No response or no response worthy of credit.
The following is a list of valid points that could be included in your answer:
- The process of natural selection.
- Grey mice can camouflage on grey rocks.
- They will not be seen easily by predators.
- The grey mice can survive in the grey rock areas.
- Grey mice reproduce and pass on the alleles for grey fur.
- The offspring inherit this characteristic.
- The population remains full of mice with grey fur.
- In the area with black rocks, the mice are only well camouflaged if they have the allele for black fur.
- The mice with the black fur allele survive but any of the mice with the allele for grey fur will not.
- The allele for black fur colour is passed onto offspring in the black rock areas because this characteristic is best suited for the environment.
