Sampling Organisms

• What are abiotic factors?

  Non-living environmental factors affecting organisms
• How do abiotic factors affect organisms?

  They influence the number of different organisms
• What technique do scientists use to determine the number of organisms in an area?

  Sampling
• What are the two methods of sampling mentioned?

  • Random sampling
  • Sampling along a transect
• What is random sampling used for?

  To compare numbers of organisms in areas
• What is a quadrat?

  A square frame for sampling organisms
• How is a quadrat used in sampling?

  It is placed on the ground to count organisms
• What hypothesis might scientists investigate using random sampling?

  Fewer ferns are found in light than dark
• How do scientists select random locations for quadrat placement?

  Using random numbers to choose locations
• Why is it important to place the quadrat multiple times?

  To ensure valid and representative results
• What can happen if the quadrat is placed only once?

  It may not represent the whole area
• What is the equation for estimating total population size?

  Total population size = total area / area sampled × organisms counted
• What is the purpose of sampling along a transect?

  • To investigate species changes across a habitat
  • To measure distances between organisms
  • To compare different habitats
• What is a transect?

  A line used for sampling organisms
• How do scientists use a transect in sampling?

  They count organisms at intervals along it
• How do species change on a sand dune?

  They change as you move inland from the sea
• What should be done after placing the first quadrat on a transect?

  Count the different plants in the quadrat
• Why is it important to repeat the transect process multiple times?

  To obtain valid data on species changes