Paper 1

• Microscopy


  1. Peel off an epidermal layer on the onion using forceps

  2. Mount onto the microscope slide with a drop of water using a pipette, making sure the tissue lies flat

  3. Add 2 drops of iodine solution to stain the cells

  4. Place the cover slip on by first placing one edge down on the slide and slowly lowering the other side of the cover slip using forceps

  5. Remove any excess stain by soaking it with paper towels

  6. Place the slide on the stage of the microscope

  7. Turn the nosepiece to select a low power objective

  8. Set up the microscope - don't look into the eyepiece yet. Instead, use the coarse adjustment knob to raise the stage until the cover slip just touches the objective

  9. Look into the eyepiece and turn the coarse adjustment knob to move the stage away until the image comes into focus

  10. Turn the nosepiece to select a high power objective

  11. Repeat the same process as above and then look into the eyepiece and turn the fine adjustment knob until the image comes into focus

  12. Make a labelled drawing of a few of the cells you can see, including any features eg. cell wall, nucleus. Write down the magnification

  13. Repeat these steps using a prepared slide
• Microbiology

  1. Spray the bench you are working on with disinfectant then wipe dry with paper towels

  2. On the bottom of the agar plate (not the lid) mark with a wax pencil / permanent marker: 3 segments, a dot in the middle of each segment, your initials, date, name of bacteria

  3. Wash your hands with antibacterial handwash

  4. Place the different antiseptics onto different filter paper discs

  5. Lift the lid of the agar plate at an angle carefully and use forceps to place each filter paper disc onto the dots. Note down the antiseptic applied to each zone

  6. Tape the lid onto the agar plate securely, but loosely enough that oxygen can still reach the bacteria

  7. Place the agar plate in the incubator at 25°C for 48 hours

  8. Measure the diameter of the clear zones after 48 hours using a ruler. Take a second measurement at 90 degrees from your first measurement and take a mean for the diameter. Do not remove the lid when taking measurements

  9. Record the results in a table
• Osmosis

  1. Use a cork borer to cut 5 potato cylinders

  2. Trim the cylinders using a sharp knife and a ruler to the same length (about 3 cm)

  3. Accurately measure and record the length and mass of each cylinder

  4. Measure 10 cm3 of the 1.0M sugar solution and transfer to the first boiling tube and label

  5. Repeat step 4 for other concentrations of the solution and distilled water

  6. Add one potato cylinder (of known mass and length) to each boiling tube

  7. Prepare a table

  8. Leave the cylinders in the boiling tubes overnight in a test tube rack

  9. Remove the cylinders from the boiling tubes and carefully blot them dry with paper towels

  10. Measure the length and mass of each cylinder and record your measurements in the table. Calculate the percentage changes for each cylinder

  11. Plot a graph of change in mass (in g) against the concentration of sugar solution

  12. Plot a graph of change in length (in mm) against the concentration of sugar solution
• Enzyme experiment


  1. Place one drop of iodine solution into each depression on the spotting tile

  2. Place labelled test tubes containing the buffered pH solutions, amylase solution and starch solutions in the water bath

  3. Allow the solutions to reach 30 °C

  4. Add 2cm3 of one of the buffered solutions to a test tube

  5. Use the syringe to place 2 cm3 of amylase into the buffered pH solution

  6. Use another syringe to add 2 cm3 of starch to the amylase/buffer solution

  7. Immediately start the stop clock and leave it on throughout the test

  8. Mix using a glass rod

  9. After 10 seconds, remove one drop of the mixture with a glass rod and place this drop on the first depression of the spotting tile with the iodine solution
• Photosynthesis experiment


  1. Set up the apparatus above, placing the funnel upside down in the beaker. However, do not insert the measuring tube into the beaker until the pondweed has adjusted

  2. Cut a piece of pondweed around 7 cm long and use forceps to place it in the beaker

  3. Using a ruler, place the lamp 15 cm away from the beaker containing the pondweed. The lamp does not have to be placed like it is in the diagram, as long as it is directed at the pondweed in the beaker

  4. Leave the apparatus for around 10 minutes to allow the pondweed to adjust

  5. Position the boiling tube upside down in the beaker, over the upside-down funnel. We will use the boiling tube to count the number of bubbles released, which is oxygen gas

  6. Count the number of bubbles in the boiling tube after one minute

  7. Repeat the count five times, recording your results in a table
• Benedicts test for sugars

  • set up a water bath using a bunsen burner
  • add food sample to test tube with a few drops of benedicts solution
  • put the test in test tube in the water bath at 80 degrees for 5 mins and note down colour changes
  • if positive should go green --> brick red
  • if negative light blue
• iodine solution for starch

  • add food sample to test tube
  • add a few drops of iodine
  • note down any colour changes in your table of results.
  • if positive goes blue-black
  • if negative orange-brown
• biruet soloution for protein

  • add food sample to test tube
  • add a few drops of biruet a and b
  • shake the solution gently and note down any colour change in your table of results.
  • if positive purple/lilac
  • if negative blue
• sudan lll test for fats

  • equal amounts of food and water
  • drops of sudan lll are added and the test tube is shaken
  • if positive a red ring will form on the surface of the water.