How do I answer a 'Describe and Explain' question?
Failing to distinguish between these two important command words can result in a lot of lost marks! ‘Describe’ involves writing a literal description of the data that is in front of you, may it be a graph or a table.
Although at times it might seem basic, it is important you state the obvious. For example, if a graph shows a strong positive correlation, you simply say ‘The greater the [insert X axis title], the greater the [insert Y axis title]’. If the data deviates from a trend, you should note the value at which it changes and describe whether it ‘flattens off’, ‘decreases’ or ‘increases’.
In order to achieve full marks in these questions you must remember to EXPLAIN. Explaining requires a reason. A brilliantly simple technique that will set you on the right track to doing this is to write ‘because’ after your description. Easy peasy!
A classic example question is “Looking at the graph given, describe and explain the effect of light intensity on the rate of photosynthesis”
So… Step 1) Describe the first trend
Up to the point of x lm/sr the rate of photosynthesis increases as light intensity increases.
Step 2) Explain the first trend
This is because light is the rate limiting factor.
Step 3) Describe the second trend
After x lm/sr, there is a plateau (levelling off) of the curve and the rate of photosynthesis remains the same.
Step 4) Explain the second trend
This is because a second factor is now limiting, such as the concentration of CO2.
