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Question 18M.2.HL.TZ1.c

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Date May 2018 Marks available [Maximum mark: 7] Reference code 18M.2.HL.TZ1.c
Level HL Paper 2 Time zone TZ1
Command term Explain Question number c Adapted from N/A
c.
[Maximum mark: 7]
18M.2.HL.TZ1.c

Explain how organic compounds are transported within plants.

[7]

Markscheme

a. transported in/translocated in/loaded into phloem

b. in sieve tubes 

c. by mass flow 

d. from sources to sinks 

e. from leaves/other example of source to roots/other example of sink 

f. loading (of sugars/organic compounds) by active transport 

g. cause high concentration of solutes (in phloem/sieve tubes) 

h. water uptake (in phloem/sieve tubes) by osmosis/water diffuses into phloem 

i. rise in (hydrostatic) pressure at source (in phloem) 

j. creates a (hydrostatic) pressure gradient/higher pressure in source than sink 

k. flow can be in either direction/bidirectional

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