iGCSE Biology (0610)-7.1 Diet – iGCSE Style Questions Paper 3

Question

(a) (i) Explain the term balanced diet.

   (ii) State three factors that influence a person’s nutritional needs.

  (b) Glucose is absorbed in the small intestine and transported in the blood. The kidneys
          filter the blood and reabsorb the glucose.
          If the blood contains more than 180 mg of glucose per 100 cm3, the kidney cannot
          reabsorb it all and some is present in the urine. This figure is called the renal
          threshold.
          A doctor suspects that a patient has diabetes because a urine test is positive for
          glucose.
          The patient takes a glucose tolerance test by drinking a solution of glucose. The doctor
          records the patient’s blood glucose concentration at 30 minute intervals for five and a
          half hours.
          The results are plotted on Fig. 2.1.

        (i) Draw a horizontal line on Fig. 2.1 to show the renal threshold.                                       [1]
       (ii) State the time period when the kidney will produce urine containing glucose.

      (iii) Sketch on Fig. 2.1 the blood glucose concentrations that the doctor might expect if
               he repeated this test on someone who does not have diabetes.                                            [1]

(c) People who do not have diabetes maintain their blood glucose concentration below
       180 mg per 100 cm³.
       Explain how the body does this.