Sampling organisms

• What should you be able to describe by the end of the video?

  Using quadrats and transects for species abundance
• What are abiotic factors?

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

  They influence the number of different organisms present
• 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 a quadrat?

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

  Place it on the ground and count organisms
• What hypothesis is investigated regarding ferns?

  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 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 abiotic factors along a line
• What is a transect?

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

  Count organisms at intervals along the line
• How do species of plants change on a sand dune?

  They change as you move inland from the sea
• What should be done to ensure valid results when sampling along a transect?

  Repeat the process multiple times
• What types of plants might be found on a sand dune?

  • Grasses
  • Small bushes
  • Small flowers
  • Trees
• Where can you find additional questions on sampling methods?

  In the vision workbook linked above