practicals

• MICROSCOPY- apparatus:

  • light microscope
  • slides
  • cover slips
  • forceps
• MICROSCOPY- method:

  1. set up the microscope
  2. place the onion in iodine on the slide with the cover slip on top
  3. view it under the microscope at low magnification
  4. then view it at high magnification
• OSMOSIS- apparatus:

  • potato
  • paper towels
  • solutions with different concentrations of salt solution
  • beakers
  • balance
• OSMOSIS- method:

  1. pour the solutions into different beakers and label them
  2. measure the mass of each potato chunk using the balance
  3. place each one in a separate beaker
  4. leave the potato chunks for a certain amount of time
  5. remove the potato chunks and use a paper towel to remove excess liquid
  6. measure the mass of the potato chunks again
  7. calculate the percentage change in mass
• FOOD TESTS- starch:

  1. put a small piece of the food on a spotting tile
  2. add two drops of iodine solution to the food
  3. if the iodine goes blue-black, then the food contains starch
• FOOD TESTS- glucose:

  1. mix a small sample of the food with benedict's solution in a boiling tube
  2. heat the mixture
  3. if the solution goes brick-red, the food contains glucose
• FOOD TESTS- protein:

  1. mix a small sample of food with biuret solution
  2. leave for around 2 minutes
  3. if the mixture goes a pale purple, the food contains protein
• POPULATION SIZE- apparatus:

  • quadrat
  • tape measures/ rulers
• POPULATION SIZE- method:

  1. randomly place the quadrat on a section
  2. record the number of the plant in each quadrat
  3. calculate the mean number of population size per m^2 for your sample area
  4. calculate the estimated population size for your sample area