DP Biology (first assessment 2025)
Question 21M.2.SL.TZ1.2a
| Date | May 2021 | Marks available | [Maximum mark: 2] | Reference code | 21M.2.SL.TZ1.2a |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | State | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
21M.2.SL.TZ1.2a
(a)
State two structural similarities between mitochondria and chloroplasts.
1.
2.
[2]
Markscheme
a. (a loop of) DNA ✔
b. 70S ribosomes ✔
c. double membrane ✔
d. electron transport chains/enzyme complexes in (internal) membranes ✔
e. enzymes in a region of fluid/in stroma and matrix ✔
f. large area of (internal) membrane/cristae and thylakoids ✔
Only two answers should be marked – the first on each line.
Do not award marks for functions rather than structures, for example ATP production.
Allow spaces inside cristae and thylakoids for mpf.
Examiners report
Surprisingly few candidates achieved two marks for this question, with many thinking that these organelles were cells with cell membranes, cell walls or even nuclei.
