Xylem experiment

Question 1

Observing xylem vessels in living plant stems

Answer 1

• Place celery stalks into water with strong dye for 24 hours
• In one specimen, make transverse cuts across the stem with a blade on a white tile
• Draw position of xylem vessels, which show as coloured spots
• In another specimen, make longitudinal cuts through region where you expect xylem vessels
• Draw xylem vessels which show as coloured lines

Question 2

How does experiment compare to micrographs of longitudinal and transverse sections?

Answer 2

Less detailed, only gives position of xylem, not other tissues, but shows the movement of water
happening in living tissue

Question 3

What are the limitations of this method on observing plant transport tissues?

Answer 3

Can only see xylem – cannot be modified to show phloem.
To get good sections where xylem vessels can be clearly seen is largely dependent on how sharp blade is and having a steady hand.
If longitudinal sections are cut in wrong place in stems then you won’t see any xylem.