Aphids are small insects that feed on the sap of rose plants. Ladybirds eat aphids.
A gardener counts the number of aphids and ladybirds on her rose plants each month.
The Table shows her results.
Table
| Month | Mean number of aphids per plant | Mean number of ladybirds per plant |
|---|---|---|
| March | 5 | 0.2 |
| April | 40 | 0.5 |
| May | 120 | 2.0 |
| June | 60 | 6.0 |
| July | 15 | 4.0 |
| August | 10 | 1.0 |
Name the type of relationship between the ladybirds and the aphids.
Give the month when the number of aphids was highest.
Explain why the number of ladybirds increased between April and June.
Explain why the number of aphids decreased between May and July.
111 exam-style questions on OCR GCSE Biology 4.1 Ecosystems, covering 4.1.1 Cycling of materials in ecosystems, 4.1.2 Microorganisms in cycling materials, 4.1.3 The carbon and water cycles, 4.1.4 Factors affecting decomposition, 4.1.5 Levels of organisation in an ecosystem, 4.1.6 Abiotic and biotic factors affecting communities, 4.1.7 Interdependence and competition, 4.1.8 Trophic levels, 4.1.9 Pyramids of biomass, and 4.1.10 Efficiency of biomass transfers. Each one has a worked solution and a mark scheme showing where the marks go.