State the principal dietary sources and describe the importance of: (a) carbohydrates (b) fats and oils (c) proteins (d) vitamins, limited to C and D (e) mineral ions, limited to calcium and iron (f) fibre (roughage) (g) water

Explain why it is more energy efficient for humans to eat crop plants than to eat livestock that have been fed on crop plants

Describe the functions of the types of human teeth in physical digestion of food