Coloured-Water Investigation

What is Coloured-Water Investigation?

A practical investigation in which a freshly cut leafy shoot, or a celery petiole, is stood in water containing a suitable stain such as eosin or red food colouring. After an hour or more the stem is cut into thin transverse sections and examined. The stain is found in the xylem, and the coloured strands can be followed into the leaf veins, which supports the conclusion that water travels through the xylem. The observation is the position of the colour; the conclusion that water moves in the xylem is an inference drawn from it.

This definition is part of the Transport in Flowering Plants chapter in Cambridge O Level Biology.

Concepts related to Coloured-Water Investigation

• xylem
• transverse section
• observation versus inference