Linking questions
Linking questions span different topics. In linking questions, it is important that you plan your answer and 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.
One way to answer linking questions is to follow these steps:
- identify exactly what the question is asking (perhaps by underlining key parts)
- identify what the link between the two parts of the question is
- make a short plan of these links (which will form the basis of your answer)
- include as much information as you can to obtain full marks (see below)
The number of marks per question part is given in this form [4 marks]. It is essential that you give four different answers if a question is worth four marks. Sometimes you can gain an additional mark by giving the units in a calculation or stating specific data points, eg After twenty-four hours the pH of the milk at room temperature had decreased by 1.2.
Linking questions will start with command words such as 'Describe...' 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 confused. 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 effect of temperature on enzymes. This is because...
Explain how and why questions often have the word 'because' in their answer. Describe questions don't.
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 the transport systems in animals and plants. [4 marks]
This question combines ideas about transport in plants and animals.
The following is a list of valid points that could be included in your answer. Each one would represent a mark. In your answer, it is important that you do not bullet point them, but link your ideas together.
- transport in animals is in blood vessels, while in plants it is in the xylem and phloem
- blood is pumped around the body by a heart in most/many animals - in plants, the force for xylem transport is evaporation of water from the leaves, while in the phloem it is transported in sieve tubes using energy from respiration
- plants have two systems, and transport is in several directions, while in animals, there is a one-way flow
- in animals, dfferent substances are transported in the same blood system, while in plants, the two systems transport different substances
Sample question 2 - Foundation
Question
The graph shows the effect of alcohol on the risk of developing one form of heart disease:
The death rate was estimated relative to people who did not drink.
Discuss what the results show. [6 marks]
This question combines ideas about alcohol, the circulatory system, the nervous system and endocrine system and techniques used in epidemiology.
The following is a list of valid points that could be included in your answer. Each one would represent a mark. In your answer, it is important that you do not bullet point them, but link your ideas together.
Six points from:
- low intake of alcohol reduces the rate of heart disease
- up to 30 g in women
- 63 g in men
- the risk then increases at a faster rate in women
- you would need to know more about the data collected/the quality of data collected
- the data shows that drinking may be of benefit in terms of heart disease, but doesn't take into account other effects of alcohol, eg on the nervous and endocrine systems
Sample question 3 - Higher
Question
Explain how the protein eaten in a piece of meat enters the body and is used by the body's cells. [6 marks]
This question combines ideas about digestion, circulation and genes and protein synthesis.
The following is a list of valid points that could be included in your answer. Each one would represent a mark. In your answer, it is important that you do not bullet point them, but link your ideas together.
Six points from:
- protein are large molecules and must be broken down into amino acids to be absorbed into the blood
- protein digestion begins in the stomach with the enzyme pepsin
- pepsin requires acidic conditions, provided by hydrochloric acid
- digestion is continued in the small intestine, in alkaline conditions
- amino acids are absorbed across the wall of the ileum, and active transport is required
- amino acids are taken to the liver in the blood and distributed to the cells
- in the cells, amino acids are assembled into body proteins
- using instructions in the genetic code
- proteins are synthesised in the cytoplasm, in a ribosome, according to the instructions provided by a messenger molecule
Sample question 4 - Higher
Question
Glyphosate is a herbicide, or weed killer. It is often sprayed on crops, including soya and wheat, genetically modified for herbicide-resistance crops to increase yields.
Some scientists are concerned about the use of glyphosate. Data they have plotted on the use of glyphosate since its introduction and rates of diabetes in the USA is shown below:
Discuss the positive and negative aspects of using glyphosate on crops. [6 marks]
This question combines ideas about diabetes, genetic modification, improving yields of crops and correlation and cause.
The following is a list of valid points that could be included in your answer. In your answer, it is important that you do not bullet point them, but link your ideas together.
Valid points would include
- weeds compete with crops for light, mineral ions and water
- weeds therefore reduce yields of crops
- if herbicide resistant crops are grown, crops can be sprayed - the crops are unaffected, but weeds killed and crop yield increases
- there is a correlation between the increase in glyphosate use and an increase in the number of people diagnosed with diabetes
- the increase in diabetes is greater than predicted/modelled from 1980s values
- but correlation doesn't mean that glyphosate is certain to be the cause
- a link would imply that glyphosate affects the crop in some way/remains in the crop
- some other factor/dietary factor may be involved
- scientists should look for a possible mechanism by which glyphosate could cause diabetes
