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 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.

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 (ideally six).

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.

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


Draw a Punnett square for a cross between a male with genotype BB for brown eyes and a female with genotype bb for blue eyes. Analyse your results in terms of percentages. [6 marks]

  • two marks for correct Punnett square
  • 100% of the offspring have brown eyes
  • 0% of the offspring have blue eyes
  • 100% of the offspring are heterozygous
  • 0% of the offspring are homozygous recessive
  • 0% of the offspring are homozygous dominant

Sample question 2 - Higher


Henderson Island in the Pacific Ocean is very small and has eight endangered species of birds. Rats live on the island and eat 95% of the birds' eggs. Scientists hope to kill all of the rats on the island by using a poison.

In Wales, a population of rats resistant to the poison was discovered in the 1960s.

Write an account to explain how this resistance developed and spread throughout Britain.

Suggest why using poison as a method of control on Henderson Island might be more successful. [6 marks]

The six marks will be awarded if all six of these points are made:

  • a mutation in one or more genes caused variation in the rat population
  • one variety became resistant to poison
  • this was an advantage to the resistant individuals
  • due to natural selection/ survival of the fittest they were able to breed
  • this allowed the resistant gene to be passed on to the offspring of the surviving rats
  • success in Henderson Island will depend on the smaller population (small island) and killing all the rats initially


Sample question 3 - Higher


A heterozygous male for tongue rolling marries a homozygous recessive female. Complete a Punnet square to show their possible offspring. Analyse your results as percentages and proportions. [6 marks]

  • two marks for correct Punnett square (other letters allowed)
  • 50% (0.5) of the offspring could tongue roll
  • 50% (0.5) of the offspring couldn't tongue roll
  • 50% (0.5) of the offspring are heterozygous
  • 50% (0.5) of the offspring are homozygous recessive