3.3 biology

• Sampling


  Finding a representative part of a larger quantity
• Quadrat


  • Square frame of known area used for sampling the abundance and distribution of slow moving organisms or plants
• Pitfall trap


  • Sampling technique used to trap animals living on the soil surface or in leaf litter
• Paired statement key


  • Pairs of statements used to identify a species
• Abiotic


  Non-living or physical factors that affect the distribution of organisms such as light intensity, soil moisture, pH of soil or water and temperature
• Biotic


  Living factors that affect the distribution of organisms such as competition for resources, disease, food availability, grazing and predation
• Indicator species


  • A species whose presence or absence can indicate the level of pollution in an environment
• Ways to minimise error light intensity


  Hold meter up and away from your body so that you do not cast a shadow over the meter while taking the reading
• Ways to minimise error soil moisture


  Probe should be wiped clean before every use and between each sample site to prevent contamination
• Ways to minimise error pH


  Probe should be wiped clean before every use and between each sample site to prevent contamination
• Ways to minimise error soil temperature

  1. Thermometer should be inserted into the soil the same depth each time

  2. Thermometer should be left to adjust before the reading is taken