active transport

Mark scheme

Marking points from the official mark scheme (May/June 2015). The mark or mark type is shown in brackets.

1. [max 4] (a)(i) 1. requires energy ;
2. [max 4] (a)(i) 2. from respiration R produced from respiration
3. [max 4] (a)(i) 3. movement of ions/molecules / substances / particles ;
4. [max 4] (a)(i) 4. (through) living/cell membrane ; Ig partially permeable
5. [max 4] (a)(i) 5. against concentration gradient / described ;
6. [max 4] (a)(i) 6. correct example, e.g. mineral ions and root hair cells/glucose and ileum A intestine for ileum
7. [max 3] (a)(ii) 1. water ;
8. [max 3] (a)(ii) 2. down (water) concentration / water potential gradient ;
9. [max 3] (a)(ii) 3. partially permeable membrane ;
10. [max 3] (a)(ii) 4. by diffusion ;
11. [max 3] (a)(ii) 5. passive / energy not required ;
12. [max 3] (b) 1. water uptake; Ig osmosis
13. [max 3] (b) 2. ref. water potential higher outside of cell/ref. concentration gradient ;
14. [max 3] (b) 3. increase in volume/cell swells ; Ig turgidity
15. [max 3] (b) 4. membrane cannot withstand pressure ; A no cell wall
16. [max 3] (b) 5. cell bursts ; A haemolysis