Question 21M.2.HL.TZ1.2b
| Date | May 2021 | Marks available | [Maximum mark: 2] | Reference code | 21M.2.HL.TZ1.2b |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Compare and contrast | Question number | b | Adapted from | N/A |
Compare and contrast mitochondria and chloroplasts in terms of the substrates they use and the products they produce.
[2]
a. ATP produced by both / ADP used by both ✔
b. oxygen produced by chloroplasts and used by mitochondria ✔
c. carbon dioxide produced by mitochondria and used by chloroplasts ✔
d. carbon/organic compounds built up in chloroplasts/anabolism and broken down in mitochondria/catabolism ✔
Do not award mpd for statements about carbohydrates or glucose (because the pyruvate used by mitochondria is not a carbohydrate).
To answer this question, candidates had to know that chloroplasts photosynthesize and mitochondria respire aerobically. They then had to compare or contrast the substrates or products of these two processes. The mean mark was 0.6 out of 2, showing that many candidates failed to do this. Well-prepared candidates had no difficulty.
