Paper 1 Exam Qs

Question 1

Explain how the pregnancy test strip works to show a positive result. (6 marks)

Answer 1

• (as) urine passes through reaction zone
• HCG hormone binds to the mobile HCG antibody (in the reaction zone)
• (passes up the stick) HCG hormone binds to the immobilised HCG antibodies in the results zone
• (the other) antibodies which do not attach to HCG
• bind to antibodies in control zone
• blue dye appears in both control and results zones (to show positive result)

Question 2

Explain how the swimmer’s body responded to running on the treadmill. (5 marks)

Answer 2

• heart rate increased to pump more blood to the muscles and lungs
• this allowed more oxygen and glucose to be delivered to the muscles
• removes carbon dioxide and lactic acid from the muscles more quickly
• breathing rate increased to bring more oxygen into the lungs and remove carbon dioxide
• the oxygen was used for aerobic respiration, which releases energy for muscle contraction

Question 3

Describe the steps involved in producing a large quantity of monoclonal antibodies for this antigen. (6 marks)

Answer 3

• mouse lymphocytes are stimulated to produce a specific antibody
• the lymphocytes are combined with a specific type of tumour cell
• this creates a hybridoma cell that can divide and produce antibodies
• single hybridoma cells are cloned to create many identical cells
• these cloned cells all produce the same specific antibody
• large quantities of the antibody are then collected and purified