Question 22N.1A.HL.TZ0.30
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1A.HL.TZ0.30 |
| Level | HL | Paper | 1A | Time zone | TZ0 |
| Command term | Question number | 30 | Adapted from | N/A |
An electron micrograph of a mitochondrion is shown.
The distance between the inner and outer membranes, which are shown by the box, is always very small. What is the advantage of this small distance?
A. Enables a high concentration of electrons to build up quickly
B. Enables a high concentration of protons to build up quickly
C. Allows fast diffusion of glucose into the mitochondrion
D. Allows fast diffusion of reduced NAD out of the mitochondrion
[1]
B
This question had an even higher discrimination index of 0.75 and as in question 27 about half of candidates answered it correctly. The discrimination index shows that it tended to be the better-prepared candidates who could identify the advantage of the small space between the inner and outer membrane of the mitochondrion. Teachers sometimes comment that images included in questions are not necessary. Interestingly both questions 27 and 30 had a diagram or micrograph that arguably was not needed, but both questions proved highly effective.
