Chapter 5

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. Note that you will lose points if you ask for hints or clues!


1. Milk is a nourishing food that contains , fats, , vitamins and minerals.

2. Milk that has been treated to remove nearly all of its fat is described as . Milk that has had about half of its fat removed is described as . Milk that has been heated to remove much of its water, and preserve it, is described as .

3. Milk that has been heated to 720C for 15 seconds to destroy disease-causing microbes is described as . Milk that has been heated to a very high temperature (e.g. 1380C) for a few seconds to destroy microbes and bacteria which make milk go sour, is described as .

4. The presence of bacteria in milk can be demonstrated by the dye test.

5. Yoghurt is produced from pasteurized milk by the action of useful . These convert sugar in milk to an that thickens the milk. Making yoghurt is a way of milk.

6. Cheese is produced from pasteurized milk by the action of and useful bacteria.

7. Rennet makes the protein in milk clot as . The remaining liquid is called . Rennet can be obtained from , certain and genetically yeast cells.

8. Cheese-making bacteria the milk protein and affect the of the cheese.

9. Whey contains protein and sugar. If whey is poured into a river, the bacteria in the water feed on it and use up the water’s supply. This leads to a reduction in numbers and types of other .

10. Whey can be used to feed or it can be to some other useful product.