DP Biology (first assessment 2025)
Question 20N.1B.SL.TZ0.2c
| Date | November 2020 | Marks available | [Maximum mark: 3] | Reference code | 20N.1B.SL.TZ0.2c |
| Level | SL | Paper | 1B | Time zone | TZ0 |
| Command term | Explain | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 3]
20N.1B.SL.TZ0.2c
(c)
Explain the differences between the results shown for vein and artery.
[3]
Markscheme
a. veins have thinner walls (than arteries);
b. veins sustain lower (blood) pressure (than arteries);
c. when stretched, veins become longer (than arteries);
d. veins have less muscle/elastic (fibre in their) walls (than arteries);
e. veins have lower elasticity/recover less/remain more stretched (than arteries after weights removed);
Accept inverse for arteries in all cases.
Do not accept a listing of numerical values without explanation.
Examiners report
In part (b) many candidates suggested that the samples should be of the same thickness.
