2.80 Geotropism

• The word 'geo' refers to gravity and 'tropic' refers to growth response therefore this means growth responses to gravity.
• For instance, if an emryonic root was growing from a seed, it wood grow downwards. This is knows as 'positive' geotripism.
• On the contrary, the embryonic shoot grows upwards towards the surface of the soil. This is known as 'negative' geotropism.
• An experiment involves taking a germinating seed, rotating it anticlockwise.
• We will see that the shoot will grow upwards, showing 'negative' geotropism whereas the embryonic root will grow downards, showing 'positive' geotropism.