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
• 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 conditions
• 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) × number counted
• What is a transect?

  A line used to sample organisms across a habitat
• How do scientists use a transect in sampling?

  Count organisms at intervals along the transect
• How do scientists carry out a transect on a sand dune?

  Place a tape measure and count plants at intervals
• Why is it important to repeat the transect process multiple times?

  To obtain valid data on species numbers
• What types of plants might be found on a sand dune?

  • Simple grasses
  • Small bushes
  • Small flowers
  • Trees
• What can be found in the vision workbook related to this topic?

  Questions on random sampling and transects
• What is the primary purpose of using quadrats and transects?

  To determine species abundance and distribution