Seedlings are grown at two temperatures with or without competing grass. Water and light are controlled.
Table
| Temperature in ∘C^{\circ}\mathrm{C}∘C | Mean mass without grass in g | Mean mass with grass in g |
|---|---|---|
| 15 | 8 | 4 |
| 25 | 12 | 6 |
Which statement is supported by the table?
Grass halves mean mass at 15∘C15^{\circ}\mathrm{C}15∘C but not at 25∘C25^{\circ}\mathrm{C}25∘C.
Higher temperature reduces mean mass only when grass is present.
Higher temperature removes the effect of grass on mean mass.
Grass halves mean mass at both temperatures used in the investigation.
39 exam-style questions on Edexcel GCSE Biology 9.1 Ecosystems and interdependence, covering 9.1.1 Levels of organisation in ecosystems, 9.1.2 Abiotic and biotic factors, 9.1.3 Importance of interdependence, 9.1.4 Parasitism and mutualism, and 9.1.5 Determining number of organisms in an area. Each one has a worked solution and a mark scheme showing where the marks go.