A biologist placed a single-celled organism in a solution with a pH different from its usual surroundings. The pH inside the cell was at the optimum level before the transfer.
Which observation is the best evidence that homeostasis occurred?
The pH inside the cell moved away from the optimum at first and then returned close to its original value
The cell continued to carry out reactions after it was transferred
The enzymes inside the cell worked more slowly immediately after the transfer
The pH of the surrounding solution stayed unchanged throughout the investigation
76 exam-style questions on AQA GCSE Biology 5.1 Homeostasis, covering 5.1 Homeostasis. Each one has a worked solution and a mark scheme showing where the marks go.