Transport of water into the plant (OCR A-level Biology)

This detailed lesson describes the transport of water into the plant as well as the movement across the cortex to the endodermis and to the xylem. Both the engaging PowerPoint and accompanying resource have been designed to cover the first part of point 3.1.3 (d) as detailed in the OCR A-level Biology A specification.

The lesson begins by looking at the specialised features of the root hair cell so that students can understand how these epidermal cells absorb water and mineral ions from the soil. Moving forwards, students are introduced to key terminology such as epidermis and root cortex before time is taken to look at the symplast, vacuolar and apoplast pathways that water and minerals use to transverse the cortex. Discussion points are included throughout the lesson to encourage the students to think about each topic in depth and challenges them to think about important questions such as why the apoplast pathway is needed for the water carrying the ions. The main part of the lesson focuses on the role of the endodermis in the transport of the water and ions into the xylem. Students will be introduced to the Casparian strip and will learn how this layer of cells blocks the apoplast pathway. A step by step method using class questions and considered answers is used to guide them through the different steps and to support them when writing the detailed description.

This lesson has been specifically written to tie in with the next lesson on the pathways and mechanisms by which water and mineral ions are transported to the leaves and then out into the air surrounding the leaves.