Back to Biology
Biology · Respiration · Heat production
Germinating seeds release heat
Two insulated flasks. The first holds soaked germinating peas; the second holds dead seeds that have been boiled (control). Both have thermometers. Over 48 hours, only the live flask warms up — direct evidence that respiration releases energy as heat.
t = 0.0 h
LIVE seeds
20.0 °C
Δ 0.0 °C above ambient
DEAD seeds (control)
20.0 °C
Δ 0.0 °C above ambient
Exam-style questions
1. Why are the dead/boiled seeds used as a control?
2. Why rinse seeds in disinfectant first?
3. Equation summarising the reaction:
4. Why is the flask lined with cotton wool / inverted?