5. Use Of Biological Resources

Question 1

Describe process of making yoghurt from milk

Answer 1

• sterilise equipment to kill unwanted bacteria
• pasteurise milk at 85 degrees for 10-30min
• milk is homogenised
• milk is cooled to 30-40 degrees to stop good bacteria being killed
• inoculated with lactobacillus for 3-12h
• if its below the optimum there’s less production and bacteria stops growing
• thickened yoghurt is stirred + cooled to 5 degrees

Question 2

Why can lactose intolerant people eat yoghurt without being ill

Answer 2

Lactobacillus ferments the lactose to lactic acid so there’s no lactose present

Question 3

Health benefits of adding fruit to sweetened yoghurt, and having fat-free yoghurt

Answer 3

Fruit increases fibre and prevents constipation, natural sweetener stops excess sugar and vitamin C prevents scurvy
Fat-free yoghurt has no fat and reduces risk of heart disease

Question 4

Selective breeding

Answer 4

Procès by which humans breed plants or animals with desired characteristics to develop them