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 loose 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:

  1. identify exactly what the question is asking (perhaps by underlining key parts)
  2. identify what the link between the two parts of the question is
  3. make a short plan of these links (which will form the basis of your answer)
  4. 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 that the biodiversity is lower on the school field. This is because…

Explain how and why questions often have the word 'because' in their answer. Describe questions don't.

Edexcel questions courtesy of Pearson Education Ltd.

Sample question 1 - Foundation


Describe how digested food molecules move from the small intestine to the heart. [2 marks]

A description linking two of the following things:

  • food molecules are absorbed/diffuse
  • into blood/plasma
  • into capillaries
  • in veins (to the heart)


Sample question 2 - Higher

Yeast use both aerobic and anaerobic respiration to release energy.


i) Which organelle in the yeast cell is the site of aerobic respiration? [1 mark]

The word equation for anaerobic respiration in yeast is:

glucose → alcohol + carbon dioxide

ii) Describe how aerobic respiration is different from anaerobic respiration in yeast. [2 marks]

i) mitochondrion/mitochondria

ii) A description including any two from the following:

Aerobic respiration:

  • uses oxygen
  • produces water
  • releases more energy
  • does not produce/release alcohol
  • anaerobic respiration occurs in the cytoplasm


Sample question 3 - Higher

Diagram showing the arteries in and around the heart

The diagram shows the coronary arteries surrounding a human heart.

The coronary arteries deliver blood to the muscle cells in the heart.

The coronary arteries can become narrowed or blocked by fatty deposits.

Suggest how the narrowing of the coronary artery may affect how the heart functions and how this may affect other body cells. [6 marks]

Your answer should include some of the following points:

Effect on heart:

  • less blood flow (through the coronary artery)
  • to cardiac/heart muscle/muscle cells
  • heart muscle cells die/do not work as effectively
  • may cause a heart attack/angina
  • less forceful contraction

Effect on rest of body:

  • less/slower blood flow to body cells/organs
  • lactic acid builds up which may casue cramp
  • causes fatigue/tiredness
  • less oxygen in the blood

Effect on heart cells and/or body cells:

  • less oxygen
  • less glucose
  • less aerobic respiration
  • less energy released
  • body cells start/increase anaerobic respiration
  • fewer waste products removed