A1. A study was made to look at the effect of breastfeeding on infant health. The infants studied were all healthy at birth. They were classified as never breastfed, partially breastfed or only breastfed, based on their feeding status in the first three months of life. The frequency of health care use was assessed for each of these groups, for three illnesses (lower respiratory infection, middle ear infection and gastroenteritis).
The table below indicates the frequency of initial and follow-up visits to the doctor, prescription of medication and hospitalizations during the first year of life. Follow-up visits and medication were seldom needed for gastroenteritis.
(a) Using the data, identify the illness
(i) that causes the greatest healthcare use in the first year of life.
(ii) for which breastfeeding causes the greatest reduction in visits to the doctor.
(b) Compare the health effects of only breastfeeding with partial breastfeeding, using the data in the table.
(c) Suggest how the composition of breast milk and artificial milk may have contributed to these results.
A2. (a) State the energy content of 100 g of carbohydrate, fat and protein.
(b) Explain the possible health consequences of diets rich in fats.
(c) Outline the consequences of protein deficiency malnutrition.
A3. (a) List two dietary sources of vitamin D.
(b) Discuss exposure to sunlight as a source of vitamin D.
A4. Outline the concept of food miles.
B1. A study was carried out to assess the effects of high-intensity interval training on heart rate. 20 subjects were randomly assigned to two groups: training and control. They underwent a test in which the exercise became harder and harder until they reached the point of exhaustion (progressive incremental test). The training group then performed nine sessions of high intensity interval training on a cycle ergometer during three weeks (1 minute at 130 % of maximal aerobic work rate with 1 minute rest intervals until they felt they were at the point of exhaustion). The control group did not do any training. Both groups then repeated the progressive incremental test.
The graphs below show the mean heart rate curves during progressive incremental tests before and after training.
(a) State three factors that would have to be considered when selecting the subjects used in this study.
(b) Describe the relationship between workload and heart rate shown by the graphs.
(c) (i) Calculate the change in mean heart rate at a workload of 90 W in the training group before and after three weeks of training.
(ii) Deduce the effect of training on heart rate.
B2. (a) The diagram below shows an elbow joint.
(i) On the diagram, label a pair of antagonistic muscles.
(ii) State the function of the structure labelled A.
(b) Explain the role of ATP in the contraction of skeletal muscle.
B3. (a) Define tidal volume.
(b) Outline the effects of training on the pulmonary system.
B4. Discuss the need for warm-up routines.