Question 1
Which statement about phloem is correct?
- It transports water and mineral ions.
- It transports sucrose and amino acids.
- It supports the plant.
- It absorbs water from the soil.
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Answer: B (1)
Question 2
State two functions of xylem and one function of phloem.
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- (xylem) transport of water / mineral ions (1)
- (xylem) support (1)
- (phloem) transport of sucrose / amino acids (1) ignore 'food' alone
Question 3
Describe where xylem and phloem are found in a cross-section of the stem of a non-woody dicotyledonous plant.
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- in vascular bundles (1)
- arranged in a ring near the outside of the stem (1)
- xylem on the inside and phloem on the outside of each bundle (1)
Question 4
Describe the position of the xylem and phloem in a cross-section of a root.
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- in the centre of the root (1)
- forms an X / star shape (1)
- phloem between the arms (of the X) (1)
Question 5
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanDescribe how the structure of a xylem vessel is related to its function.
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- thick walls (1)
- containing lignin, which strengthens / supports / stops the vessel collapsing (1) ignore details of lignification
- no cell contents, so water flows without obstruction (1)
- no cross walls / cells joined end to end, forming a long continuous tube (1)
Question 6
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanWhich feature of xylem vessels allows water to move up in a continuous column?
- thick walls
- lignin in the walls
- no cross walls between cells
- a nucleus in each cell
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Answer: C (1)