Three- and four-mark questions
You will be expected to write in more depth for three- and four-mark questions. They might ask you about a process such as digestion or ventilation or compare differences, such as with blood vessels.
Remember to try to answer in complete sentences.
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
Describe how a sample of food could be tested for reducing sugars.
[4 marks]
- grind up the food or dissolve the food in water
- transfer to a test tube and add 1 cm3 of Benedict's solution
- heat the test tube in a water bath for five minutes
- a colour change to red or brown, or through any of the intermediate stages of green → yellow → orange, demonstrates that a reducing sugar is present in the food sample
In an exam, you would not be penalised if the method you described was slightly different - for instance, if you had suggested using 2 cm3 of Benedict's solution instead of 1 cm3.
However, do try to specify a level of detail in your answer rather than be vague, for instance about the volume of Benedict's solution used.
Sample question 2 - Foundation
Question
Describe the differences between arteries and veins. [4 marks]
Marks are awarded for a comparison of each characteristic.
Four marking points from:
- structure: arteries have a thick wall of muscular, elastic and connective tissue, while the layers in the walls of veins are thinner
- blood flow: arteries have a narrow lumen, while veins have a wide lumen - blood in arteries is pumped under pressure, while (because of the low pressure) veins have valves to prevent the back flow of blood
- direction of flow: arteries take blood away from the heart, while veins take blood back to the heart
- oxygenation: arteries transport oxygenated blood, except for the pulmonary artery, while veins transport deoxygenated blood, except for the pulmonary vein
Sample question 3 - Higher
Question
Explain the changes that occur in the thorax as a person breathes in. [3 marks]
Three marking points from this sequence:
- the ribs move upwards and outwards
- the diaphragm flattens
- with the increase in volume in the thorax, the air pressure is lowered
- the pressure is now lower than the air pressure
- so air moves into the lungs passively
Question
Describe the digestion of starch in the body. [4 marks]
Four from:
- starch digestion begins in the mouth
- the enzyme, amylase that is released is contained in saliva
- amylase catalyses the breakdown of starch into maltose
- in the duodenum, pancreatic amylase contains enzymes that continue the digestion of starch and maltose
- starch digestion is completed by enzymes in the ileum (these are actually in the wall of the ileum)
- human amylases work best around neutral/slightly alkaline pHs and these are created by the secretion of sodium hydrogencarbonate
