B2 REVISION – Organisms in their environment Physical Factor How does it affect organisms? Temperature Nutrients Amount of light Availability of water O2 and CO2 availability Key definitions: Mean: Median: Mode: Reproducible data: Valid data: Quadrats What is a quadrat? What do we use it for? How do you use it? What is random sampling? Transects What is it? Explain how do you use a transect Is it random? 1

Factors That Affect Organisms Temperature Nutrient availability Amount of light Water availability Oxygen availability Carbon dioxide availability

Quadrats

Random Sampling 50 10, 30 50, 20 70, 40 30, 70 etc

Transect

Validity of the Method Are they using the correct method? Are they sampling in a systematic or random way?

Reproducibility of the Data Can other people carry out the experiment? Would they get the same results?

Sample Size A large sample makes data more valid and reproducable