Investigating Translation

Question 1

Describe the use of tracer experiments to investigate translocation in plants?

Answer 1

1. Supply the leaf with a radioactive tracer. This can be carbon dioxide with contains radioactive carbon14.
2. The radioactive carbon will be incorporated into organic substances during photosynthesis.
3. These move around the plant by translocation.
4. Movement can be tracked by a Gelger counter.

Question 2

Describe the use of ringing experiments to investigate transport in plants?

Answer 2

1. Remove the phloem.
2. Bulge forms on the source side of the ring.
3. This shows that there is a high pressure at the sources.
4. There fluid from the bulge has a high sugar concentration, which shows that sugars are transported in the phloem.
5. Tissues below the ring die as they can’t get organic substances.