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Question 18M.2.HL.TZ2.5c

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Date May 2018 Marks available [Maximum mark: 3] Reference code 18M.2.HL.TZ2.5c
Level HL Paper 2 Time zone TZ2
Command term Outline Question number c Adapted from N/A
c.
[Maximum mark: 3]
18M.2.HL.TZ2.5c

Every cell is surrounded by a cell surface membrane which regulates the movement of materials into and out of the cell.

(c)

Outline the process used to load organic compounds into phloem sieve tubes.

[3]

Markscheme

a. active transport/loading of sucrose/amino acids/organic metabolites 

b. sucrose moves by apoplastic / symplastic routes 

c. «loading» at source into companion cells «of sieve tubes» 

d. movement «of sucrose» through plasmodesmata 

e. high concentration of solutes in phloem leads to water movement by osmosis

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