Tube Number | Kept in: | Contents of tube | Colour at start | Colour at end | Conclusion/explanation |
1 (left) | light | snails | orange | yellow | respiration only - by animals |
2 | snails and pondweed | orange | respiration by animals and plants balanced by photosynthesis by plants | ||
3 | pondweed | red | photosynthesis exceeds plant respiration | ||
4 | dark | snails | yellow | animal respiration only | |
5 | snails and pondweed | yellow | both plant and animal respiration | ||
6 (right) | pondweed | yellow | plant respiration only |