REQUIRED PRACTICAL

• how do you use a microscope? (5)

  1. turn to the low power objective

  2. looking from the side turn the coarse adjustment knob until it is almost touching the slide

  3. look through and turn the coarse knob until the cell comes into focus

  4. turn to the high power objective

  5. use the fine adjustment knob to focus
• what is the method for the microscopy required practical?

  1. place a drop of water onto a slide

  2. peel some epidermal tissue from an onion and place on the slide

  3. add two drops of iodine onto the tissue

  4. lower a coverslip onto the slide

  5. blot with paper towel

  6. place on stage
• what is the method for the microbiology required practical? (5)


  1. clean and sterilize everything

  2. name the agar plate and divide into different sections

  3. place paper discs soaked in antiseptic and place these in the different sections

  4. incubate for 48 hours at 25℃

  5. measure the diameter of the clear zones and find the mean
• what are decontamination precautions in the microbiology practical?


  - passing the inoculation loop through a flame

  - wash hands before and after

  - sterilize workbench with disinfectant spray
• what is the method for the osmosis required practical? (6)

  1. cut and trim potato cylinders

  2. measure mass and length of the cylinders

  3. put the cylinders into different concentrations of sugar/salt solutions and one in distilled water

  4. leave for a chosen amount of time

  5. take out, blot with paper

  6. measure mass and length and record percentage change
• what is the food test for sugars?

  - place food sample in a water bath at 80℃ and add benedict's solution

  - positive result: blue → green, yellow, brick red
• what is the food test for starch?

  - add iodine solution

  - positive result: orange-brown → blue-black
• what is the food test for lipids?

  - add sudan iii and gently shake

  - positive result: forms a bright-red top layer
• what is the food test for proteins?

  - add biuret solution and gently mix

  - positive result: blue → pink/purple
• what is the method for the photosynthesis required practical? (5)

  1. place a 10cm piece of pondweed in a beaker of water

  2. cover the pondweed with an inverted filter funnel

  3. fill the cylinder with with water and position one meter away from the light source

  4. start the stop watch and record the number of bubbles released and the volume of gas produced in the measuring cylinder

  5. repeat at different distances from the light source
• what is the method for the enzymes practical? (7)

  1. heat water bath to 35℃

  2. add buffered solution

  3. add starch solution

  4. place a thermometer to monitor temperature

  5. add amylase solution

  6. start stopwatch and add a drop of mixture to iodine on a spotting tile and continue until the iodine turns orange

  7. record time and repeat with different pHs