5.22—Core Practical 12 - temperature and organism development

To test temperature effects on development, place comparable seeds or eggs at different temperatures while keeping light, water, pH, oxygen, food, age and time controlled. Measure growth or hatching rate rather than a final count alone.

Use replicates, calculate an average rate, record the temperature reached, and look for an optimum rather than assuming a straight trend. Living organisms require humane handling and suitable end conditions.

Seedling growth rate can be calculated as average height change divided by days; brine-shrimp hatching rate is hatched eggs divided by hours. Both may rise to an optimum then fall.

A difference between treatments is not causal if another variable changed with temperature. Small sample sizes, uneven starting material or poor welfare can undermine the conclusion.