A group of students investigates the effect of different concentrations of indole-3-acetic acid (IAA) on the elongation of oat coleoptile segments. They set up three experimental treatments:
- Treatment P: Coleoptiles incubated in a 10−6 mol dm−310^{-6}\text{ mol dm}^{-3}10−6 mol dm−3 IAA solution. This treatment contains 8 coleoptile segments with an initial length of 10 mm, incubated at 25∘C25^\circ\text{C}25∘C in a shaking water bath for 24 hours.
- Treatment Q: Coleoptiles incubated in distilled water (0 mol dm-3 IAA). This treatment contains 8 coleoptile segments with an initial length of 10 mm, incubated at 15∘C15^\circ\text{C}15∘C on a static lab bench for 24 hours.
- Treatment R: Coleoptiles incubated in a 10−2 mol dm−310^{-2}\text{ mol dm}^{-3}10−2 mol dm−3 IAA solution. This treatment contains 3 coleoptile segments with an initial length of 15 mm, incubated at 25∘C25^\circ\text{C}25∘C in a shaking water bath for 12 hours.