One to four mark questions will start with command words such as 'describe' or 'explain'. Some command words are easy to understand such as:
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). For example, 'The graph shows a steep linear increase for the first three hours 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 '[2 marks]'. It is essential that you give two different answers if a question is worth two marks. Sometimes you can gain a second mark by giving the units in a calculation or stating specific data points, eg 'During the first two years the number of lions decreased by seven.'
You will be expected to write in more depth for three and four mark questions. They might ask you about a process such as the carbon cycle or the method you would use in an experiment.
While the examples below are given as bullet points, you should always write your answers in full sentences.
These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.
Give two differences between plant and animal cells. [2 marks]
Any two from:
Describe the effect of temperature on the rate of reaction of the enzyme. [3 marks]
The rate of reaction increases as the temperature increases up to the optimum temperature. 
As temperatures increase above the optimum the rate of reaction decreases to 0. 
The enzyme is now denatured and won't work. 
Define the term stem cell. [1 mark]
A stem cell is an undifferentiated cell. 
Name the type of cell in plants that can differentiate into different types of cell. [1 mark]
Meristem cell or meristematic cell. 
Note that you must be specific. It isn't sufficient to call it a 'stem cell', as stem cells occur in animals.
Compare the location of the genetic information in a prokaryote and eukaryote cell. [2 marks]
The genetic information in a eukaryotic cell is enclosed in a nucleus. 
The genetic information in a prokaryotic cell is loose in the cytoplasm.