Intermediate Level

Tracking active uptake of minerals by plant roots

Introduction

This is a thinking exercise only, rather than a practical protocol, but provides a data set to analyse as described on the student sheet.

Lesson Organisation

Hand out the student sheets (289 KB). Talk through the protocol. Allow students to work through the questions. The later questions are more demanding and some students may need more support.

Apparatus And Chemicals

For each group of students:

Copies of the student sheet
Graph paper
Pencil
Ruler

Health & Safety

Read our health and safety guidelines

Technical Notes

The rate of uptake of sulfate ions is faster in aerobic conditions, which suggests that the presence of oxygen improves the ability of the seedlings to take up sulfate ions. As oxygen is used in respiration (the process by which energy is made available) it is reasonable to suggest that the data support the hypothesis that mineral uptake by plants is an active process. However, the data for anaerobic conditions suggest that, in this experiment at least, diffusion can account for the uptake of some of the sulfate ions.

The half-life of radioactive sulfur is 88 days, and the course of this investigation is 4 hours. Therefore, although the data for sulfate uptake will be a slight underestimate – it is only slight.

Health & Safety checked, September 2009

Downloads

Download a student sheet with questions and answers here (289 KB).

Related practicals

Estimating rate of transpiration from a plant cutting
Investigating the effect of minerals on plant growth

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