Acknowledgements; Contents; Introduction; Unit 9A Inheritance and selection; Unit 9B Fitness and health; Unit 9C Plants and photosynthesis; Unit 9D Plants for food; Unit 9E Reactions of metals and metal compounds; Unit 9F Patterns of reactivity; Unit 9G Environmental chemistry; Unit 9H Using chemistry; Unit 9I Energy and electricity; Unit 9J Gravity and space; Unit 9K Speeding up; Unit 9L Pressure and moments; Scientific investigations; Glossary/index