Food and ecosystems - Maths questions
Maths questions will appear throughout both exam papers (Breadth and Depth), and at both Foundation tier and Higher tier.
Don't forget to take a ruler and a calculator into the exams.
Maths questions often start with the command word 'calculate', followed by a blank space for your working. It is important that you show your working – don't just write the answer down. You might earn marks for your working even if you get the answer wrong.
Always include the correct units for your answer, unless they are already given on the answer line. This may earn you an additional mark.
Check carefully to see if the question tells you to round your answer to a particular number of significant figures or decimal places. And don't forget to check your rounding.
If the question does not tell you to round your answer but it has lots of decimal places, you should give your answer to the same number of significant figures as the data in the question. For example, if two significant figures are used in the question, then usually your answer should also be given to two significant figures.
Other command words you might see in maths question include:
- 'predict' (look at some data and suggest an outcome – don't just guess, look at trends in the data and use your scientific knowledge and understanding to make a sensible suggestion)
- 'estimate' (suggest a rough value without doing a calculation – don't just guess, use your scientific knowledge and understanding to make a sensible suggestion)
- 'show' (write down the details, steps or calculations to prove that an answer is correct)
Maths questions might include tables and graphs as well as calculations. When drawing a graph, make sure you:
- put the independent variable (the factor you changed) on the x-axis
- put the dependent variable (the factor you measured) on the y-axis
- construct regular scales for the axes
- label each axis with the quantity and units, eg time (s)
- plot each point accurately
- decide whether the origin (0,0) should be used as a data point
- draw a straight or curved line of best fit if appropriate
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
Two students recorded the number of birds they saw in one hour in two gardens.
The owners of garden A put out food on their bird table every day for five days. The owners of garden B moved out a month ago. No food has been put out in garden B in the last month. On day 5 they couldn't get into garden B so no results were recorded.
Table 1 shows the number of birds in each garden seen during a single hour.
| Day 1 | Day 2 | Day 3 | Day 4 | Day 5 | |
| Garden A | 7 | 5 | 4 | 5 | 4 |
| Garden B | 1 | 2 | 1 | 2 | No results |
| Garden A | |
|---|---|
| Day 1 | 7 |
| Day 2 | 5 |
| Day 3 | 4 |
| Day 4 | 5 |
| Day 5 | 4 |
| Garden B | |
|---|---|
| Day 1 | 1 |
| Day 2 | 2 |
| Day 3 | 1 |
| Day 4 | 2 |
| Day 5 | No results |
Calculate the mean for both gardens. [2 marks]
To calculate a mean all the values must be added up and then divided by the total number of values.
Garden A: 7 + 5 + 4 + 5 + 4 = 25 ÷ 5 = 5
Garden B: 1 + 2 + 1 + 2 = 6 ÷ 4 = 1.5
Sample question 2 - Foundation
Question
The table below shows the results from an ecological experiment.
| Quadrat | Number of species |
| 1 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 2 |
| 5 | 2 |
| 6 | 1 |
| Quadrat | 1 |
|---|---|
| Number of species | 1 |
| Quadrat | 2 |
|---|---|
| Number of species | 3 |
| Quadrat | 3 |
|---|---|
| Number of species | 4 |
| Quadrat | 4 |
|---|---|
| Number of species | 2 |
| Quadrat | 5 |
|---|---|
| Number of species | 2 |
| Quadrat | 6 |
|---|---|
| Number of species | 1 |
What is the median result? [1 mark]
| A | 1 |
| B | 2 |
| C | 3 |
| D | 4 |
| A |
| 1 |
| B |
| 2 |
| C |
| 3 |
| D |
| 4 |
B
To calculate this place the set of numbers in increasing order of size. The median is the middle number. In increasing order of size: 1, 1, 2, 2, 3, 4. The answer is therefore 2.
Sample question 3 - Higher
Question
A student measured the change in mass of potato cylinders placed in different concentrations of salt solution. Their results are shown below.
| Concentration (mol dm-3) | 0.0 | 0.1 | 0.2 | 0.3 | 0.4 |
| Average change in mass (%) | +10 | +2 | -3 | -6 | -8 |
| Concentration (mol dm-3) |
|---|
| 0.0 |
| 0.1 |
| 0.2 |
| 0.3 |
| 0.4 |
| Average change in mass (%) |
|---|
| +10 |
| +2 |
| -3 |
| -6 |
| -8 |
Plot these points on graph paper and draw a line of best fit. [4 marks]
Your graph should look like this.
Axes and scales correct – 1 mark.
All points plotted correctly – 2 marks or 2 to 3 points plotted correctly – 1 mark.
Appropriate line of best fit – 1 mark.
You should have concentration on the horizontal axis and percentage mass change on the vertical axis. The vertical axis has a positive and negative scale. Your divisions on your scales should be regular. Your axes should be labelled and include units.
All points should be plotted accurately.
You should have drawn an appropriate line of best fit. In this case, it is a curve.
Sample question 4 - Higher
Question
In an osmosis experiment, after 45 minutes, a potato cylinder had lost 2.4 g in mass.
Calculate the rate of water loss from the potato cylinder in grams per hour. [2 marks]
3.2 g h-1
45 minutes = 0.75 h
The water lost in 0.75 h is 2.4 g
Therefore, 2.4/(0.75 ) g of water would be lost in 1 hour
The rate of water loss is 3.2 g per hour, or written more scientifically, 3.2 g h-1.
More guides on this topic
- What happens during photosynthesis? - OCR 21st Century
- How do producers get the substances they need? - OCR 21st Century
- How do producers transport substances they need? - OCR 21st Century
- How are organisms in an ecosystem interdependent? - OCR 21st Century
- How are levels maintained within an ecosystem? - OCR 21st Century
- How are populations affected by conditions in an ecosystem?
