Water has not always been as available or as safe to drink as it is today. During the nineteenth century there were many public health concerns resulting in the passing of a number of Acts of Parliament, notably the Public Health Act of 1848. Since then it has been accepted that it is important to monitor the sufficiency and wholesomeness of water supplies, not just for the protection of the public, but also to ensure that the wider interests of the community and the environment are met.

1. What is the primary energy source of living organisms on earth?

2. How is light from the sun transformed into the chemical energy used by living organisms on earth?

3. What is the chemical equation for photosynthesis?

4. What living organisms are responsible for photosynthesis?What cell organelle is responsible for the absorption of light in the photosynthesis process in plants and algae?

5. Are there chloroplasts in cyanobacteria?

6. Which chemical element is at the center of the chlorophyll molecule?

7. How do chloroplasts multiply?

8. What evidence is there to support the hypothesis that chloroplasts and mitochondria were primitive prokaryotes that developed a relationship of mutualism with primitive anaerobic eukaryotic cells?

9. What are the main structures of chloroplasts?

10. In which chloroplast structure are chlorophyll molecules found?