AQA
A-Level
BIOLOGY
3.3 | Organisms Excange Substances
3.6 | Mass Transport in Plants
Time allowed
38 minutes
MARK SCHEME
Score Percentage
/32 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
, 1.(a) 1. In source / leaf sugars actively transported into phloem;
2. By companion cells;
3. Lowers water potential of sieve cell / tube and water enters by osmosis;
4. Increase in pressure causes mass movement (towards sink / root);
5. Sugars used / converted in root for respiration for storage.
Accept starch
4 max
(b) Respiration.
1
(c) 1. (About) 30 hours;
2. Time between peak 14C at top of trunk and bottom.
2
(d) Length of trunk (between top and bottom).
1
[8]
A-Level
BIOLOGY
3.3 | Organisms Excange Substances
3.6 | Mass Transport in Plants
Time allowed
38 minutes
MARK SCHEME
Score Percentage
/32 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
, 1.(a) 1. In source / leaf sugars actively transported into phloem;
2. By companion cells;
3. Lowers water potential of sieve cell / tube and water enters by osmosis;
4. Increase in pressure causes mass movement (towards sink / root);
5. Sugars used / converted in root for respiration for storage.
Accept starch
4 max
(b) Respiration.
1
(c) 1. (About) 30 hours;
2. Time between peak 14C at top of trunk and bottom.
2
(d) Length of trunk (between top and bottom).
1
[8]
