A feeding study follows what happens to food eaten by a young fox.
| Outcome | Observation |
|---|---|
| P | Large food molecules pass out of the digestive system without being broken down. |
| Q | Absorbed food molecules are converted to carbon dioxide and water as energy is released. |
| R | Urea made from absorbed food substances passes out of the body. |
| S | Absorbed food molecules become part of new muscle. |
Give the letter of the outcome that contains undigested biomass.
Name the process represented by outcome Q.
State the route by which the substance in outcome R leaves the fox's body.
Give the letter of the outcome in which the biomass could be passed on to the next trophic level.
103 exam-style questions on AQA GCSE Biology 7.4 Trophic levels in an ecosystem, covering 7.4.1 Trophic levels, 7.4.2 Pyramids of biomass, and 7.4.3 Transfer of biomass. Each one has a worked solution and a mark scheme showing where the marks go.