The table below describes four different ecosystems and the amount of energy converted into plant biomass each year in each ecosystem:
| Ecosystem | Description | Energy converted into plant biomass (kJ m−2 yr−1\text{kJ m}^{-2}\text{ yr}^{-1}kJ m−2 yr−1) |
|---|---|---|
| T | Subarctic coniferous forest | 15 000 |
| U | Managed glasshouse tomato crop | 92 000 |
| V | Semi-arid wild scrubland | 6 500 |
| W | Irrigated intensive alfalfa field | 38 000 |
Identify three abiotic (non-living) factors, other than light intensity, likely to affect the rate of photosynthesis in these ecosystems.
Ecosystems V (semi-arid wild scrubland) and W (irrigated intensive alfalfa field) experience the same macroclimate. Suggest two reasons, other than selective breeding of the crops, why more energy is converted into plant biomass in ecosystem W than in ecosystem V.
State what is meant by the term selective breeding.
Describe how you could use a quadrat to estimate the total dry plant biomass in Ecosystem V, which has a total area of 1200 m2\text{m}^2m2.
74 exam-style questions on Edexcel IGCSE Biology Food production. Each one has a worked solution and a mark scheme showing where the marks go.