Bio P1 PPQs

• Describe how the student should adjust the microscope to see the cells on Slide A more clearly.

  Turn the (fine focusing) knob until the cells are in focus.
• Explain what a non-communicable disease is.


  Is not caused by a pathogen so is not spread from person to person.
• Explain how CHD can cause a heart attack.

  restricted blood flow (so) less oxygen reaches heart so (heart muscle / cells) cannot respire enough.
• Explain how lifestyle and medical risk factors increase the chance of developing CHD.

  smoking – high bp / cholesterol / fatty deposition

  • obesity – lack of exercise / high bp / cholesterol / fatty deposition / diabetes

  • lack of exercise – obesity / bp /diabetes

  • bad diet – obesity / cholesterol / diabetes
• Suggest two ways the method could be improved to measure the rate of photosynthesis more accurately.

  • Measure the volume of gas released
  • Increase length of time.
• Describe how the student could change the method to investigate the effect of carbon dioxide concentration on the rate of photosynthesis. You should include: • how to change the independent variable • two control variables

  • use different concentrations of sodium hydrogencarbonate solution
  • distance from light source
  • temperature of solution
• Suggest why the student calculated the percentage (%) change in mass of each piece of carrot.

  To control the starting mass of the carrots as they are not all the same mass.
• Explain why the mass of the carrot in the 0.6 mol/dm3 sugar solution changed.

  mass decreased (due to) loss of water by osmosis through a partially permeable membrane (as) concentration of sugar solution is greater than concentration of sugar (solution) inside cells / carrot
• The student repeated the investigation using boiled pieces of carrot. The pieces of carrot did not change in mass. Suggest why.

  The cells membrane was damaged
• Describe what happens in each of the three stages of the cell cycle.

  • Increase in number of organelles
  • DNA replicates
  • One set of chromosomes moves to each end of cell
  • Nucleus divides
  • Cell membrane divides to form two identical daughter cells
• Give two advantages and two disadvantages of therapeutic cloning in medical treatments.

  Advantages:

  • cells unlikely to be rejected by the patient
  • would reduce waiting time for organ transplants
  • Disadvantages:
  • may transfer (viral) infection
  • potential life is killed / destroyed
• Give one reason for what is happening to the number of bacteria at each of the stages.

  (A) (no change in population size) because no / limited cell division / reproduction

  (B) (rapid increase in population size) as cells dividing rapidly as (plentiful) supply of nutrients / food

  (C) (population size stays the same) as rate of cell death equals rate of cell division

  (D) (population size decreasing) as cells dying due to nutrients running out
• Describe why there are air holes in the cap of the culture bottle.

  As Bacteria need oxygen to respire
• Some people who take beta blockers get out of breath when they exercise. Explain why beta blockers can have this effect during exercise.


  -During exercise the body needs to transfer more energy during respiration so the rate of respiration would increase meaning more oxygen would be needed.

  -As the beta blockers reduce heart rate so the heart can not supply oxygen

  -Breathing rate increases to increase rate but cannot fully compensate for for changing functions of the heart