RPs

• Reaction time required practical

  1. Hold a ruler (just) above the (open) hand of the other student

  2. Drop the ruler and other student catches it

  3. Record where the ruler is caught

  4. Read reaction time from table
• Sampling an area using a quadrat

  1. Calculate the area of the habitat

  2. Random placement of quadrat a suitable number of times (more than 10% of area)

  3. Record number of a particular species in each quadrat

  4. Calculate mean number of chosen species per quadrat (total number of species in all samples + total number of quadrats)

  5. Calculate mean number per m2 (x 4 if a 0.5m x 0.5m quadrat)

  6. Multiply number per m² by total area of habitat to get an estimate of the total population
• Improving the population estimate

  • Using a greater number of quadrats (more samples)
  • Ensuring true randomness of placement
• Sampling along a transect

  1. Mark out transect using a tape measure

  2. Place quadrat at regular intervals next to the transect

  3. Count number of individuals of each species present in quadrat

  4. Comment on why the population changes across the transect