Core Pracs

Change: herbicides etc… Organism: plant of same age, species, source Repeat: Each herbicide 4x, calculate mean, discard anomalies Measure: Time taken to decolorise DCPIP, use a colorimeter. Same: temperature (water bath), pH, light intensity Isolate chloroplasts in centrifuge Have tubes in the dark as a control

Change: Plant material on disk Organism: Same species of bacteria Repeat: 4x, calculate mean, discard anomalies Measure: area of inhibition Same: Concentration of plant material, temperature (water bath) Work next to a bunsen burner, disinfect and sterilize equipment before use, spread lawn of bacteria onto agar gel

Change: temperature (water bath) Organism: same species, same age, same mass Measure: Volume of oxygen produced in 30 seconds - initial rate of reaction. Q10 = rate at temp + 10/ rate at temp Same: volume of hydrogen peroxide, concentration of hydrogen peroxide Peas + hydrogen peroxide should be left in water bath separately for 10 minutes before combined.

. Change: 2 temperatures differing by 10 with water bath . Organism: provide excess triglyceride . Repeat: each temperature 5x, calculate mean, discard anomalies . Measure: Concentration of triglyceride every 30s for 15 minutes. . Same: concentration of lipoprotein lipase . Calculate initial rate by plotting graph of time vs concentration and calculating gradient of tangent. . Q10= Rate at T / Rate at T + 10

Replace trees that have been cut down Cut down older trees Replace with young trees

. To calibrate . Allows repetition . Returns colored liquid back to zero