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
The graph shows the breathing rate of a student before, during and for a period after exercise.
Explain fully the student's data. [4 marks]
This question combines ideas about respiration, gas exchange and homeostasis.
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.
Marking points are made from:
- there is an increase in breathing rate when exercise starts
- increases slowly, from 5 to 10 minutes, then more rapidly from 10 to 15 minutes
- it is because the muscles need more oxygen, collected at the lungs
- the oxygen is delivered to the student's muscles by the blood
- the volume of air breathed is also likely to have increased
- the breathing rate is at a steady rate from 15 to 20 minutes, as it meets the demands of the respiring muscles
- when exercise stops, the breathing rate does not return to normal straightaway
- the extra oxygen is required to remove lactic acid that has been produced during exercise
When describing the trends use data from the graph to support your answer.
Sample question 2 - Foundation
A student set up an experiment to investigate gas exchange in plants and animals.
He set up a series of boiling tubes. Each boiling tube contained hydrogencarbonate indicator.
Hydrogencarbonate indicator is used to show the concentration of carbon dioxide levels.
It becomes orange, then increasing yellow as carbon dioxide is added to it.
It becomes increasingly purple as carbon dioxide is removed.
The student's results are shown below.
Question
Explain the student's results fully. [4 marks]
This question combines ideas about photosynthesis and respiration, and also working scientifically.
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.
Marking points are made from:
- the tube containing neither snails nor plant leaves is set up as a control
- to see the extent to which the colour of hydrogencarbonate indicator would change without either organism
- the hydrogencarbonate indicator changes in colour slightly - it is more orange - because of (the low) carbon dioxide levels in the air
- plant leaves remove carbon dioxide for photosynthesis, so the hydrogencarbonate in this tube turns purple
- in the tube with the snails, the hydrogencarbonate turns yellow because of the carbon dioxide produced by respiration
Sample question 3 - Higher
Question
Describe and explain the metabolism of proteins and amino acids in animals. [6 marks]
This question combines ideas about digestion, protein synthesis, homeostasis and excretion.
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.
Marking points are made from:
- the size of protein molecules means that they must be broken down into amino acids to be absorbed into the blood
- 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 synthesised in the cytoplasm, in a ribosome, according to the instructions provided by a messenger molecule
- excess amino acids are taken to the liver and converted to ammonia
- ammonia is toxic are converted to urea, which is excreted by the kidneys
- protein and amino acids are used to provide energy at times of starvation
Sample question 4 - Higher
Question
Describe the way in which the energy released in respiration is used in animals. [6 marks]
This question combines ideas about respiration, cell biology, homeostasis and the circulatory system.
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.
Marking points are made from:
- all organisms need energy to carry out the seven life processes
- chemical reactions building up complex carbohydrates, proteins and lipids from the products of photosynthesis in plants require energy
- chemical reactions building up complex carbohydrates, proteins and lipids from the products of digestion in animals require energy
- for movement - in animals, energy is needed to make muscles contract, while in plants, it is needed for phloem transport
- heat released as by-product of respiration is distributed around the body by the blood of birds and mammals and helps to keep these animals warm and maintain a constant internal temperature
- used for cell division
- maintain constant conditions in cells and in the body - homeostasis
- used to transport molecules by active transport
- used to transmit nerve impulses
