Question 23M.1.HL.TZ2.29
| Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.1.HL.TZ2.29 |
| Level | HL | Paper | 1 | Time zone | TZ2 |
| Command term | Question number | 29 | Adapted from | N/A |
What is a benefit of having xylem vessels close to phloem sieve tubes in plants?
A. Sugars can flow in both xylem vessels and phloem.
B. Water can be supplied more easily to the phloem.
C. A high concentration of solutes can be established at the source.
D. Hydrostatic pressure can be established to move sugars to the source.
[1]
B
This question asked the candidates to state the benefit of having xylem vessels close to sieve tubes in plants. The correct response is that water can be supplied more easily to the phloem. Some G2 comments suggested that D is also correct as sugars can move in both directions through sieve tubes, but this was considered incorrect as movement is always away from the source, even if that source was at one time a sink.