As an undergraduate research assistant in the lab of the famous Dr.S.Nameerf,you are assisting with a radioisotope tracer experiment.You expose a mature leaf on one side of the lower shoot of a sugar beet plant to ¹⁴CO₂ and then track the movement of the ¹⁴C atoms by radiography.Where are you least likely to detect ¹⁴C?

Question

Quizplus · Accepted Answer

The ¹⁴C atoms are expected to move from the treated leaf to the rest of the plant through phloem transport. As phloem moves primarily in the downward direction, it is unlikely for the ¹⁴C atoms to reach a mature upper leaf on the opposite side of the plant from the treated leaf. However, it is expected that some of the ¹⁴C atoms will reach the shoot apical meristem to promote plant growth, and also the roots, as they are the major organs responsible for nutrient uptake. The young leaf directly above the treated leaf may also show some presence of the ¹⁴C tracer, as it is connected to the same phloem transport system.

As an Undergraduate Research Assistant in the Lab of the Famous