This post-16 resource looks at root growth, with a focus on gravitropism. Roots are the hidden half of a plant, but they are responsible for providing the plant with all the water and minerals they need to grow. Understanding roots better can help scientists breed crops that use fertiliser more efficiently, and which can cope with either drought or water-logging. This research could be particularly important for small farmers in the developing world, especially as climate change affects their growing conditions.  

This experiment using agar plates and white mustard seeds allows students to visualise the development of roots, their root hair cells, and observe the zones of elongation and differentiation. They will then use a graticule to measure their length.  Students can then extend their investigations to observe the effect of an obstruction in the path of the roots, visualise the xylem in roots using food dye, and observe gravitropism in the roots.

The resource was inspired by Prof Malcolm Bennett's lecture at the Gatsby Plants Summer School, in which he asked whether actively breeding crops for root capacity help feed the developing world. The lecture was filmed and is available to view online from the Gatsby TREE online teaching resource collection. (Free registration required)

Watch Prof Malcolm Bennet's lecture online

This resource was developed by Dr Iona Martin of Colchester County High Girls School, after attending the Gatsby Plants Summer School 2013.