DP Biology (last assessment 2024)
Question 18N.3.SL.TZ0.18
| Date | November 2018 | Marks available | [Maximum mark: 3] | Reference code | 18N.3.SL.TZ0.18 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Explain, Label | Question number | 18 | Adapted from | N/A |
18.
[Maximum mark: 3]
18N.3.SL.TZ0.18
The image shows a section through the ileum as viewed under the light microscope.
(a)
On the diagram, label the epithelial cell layer.
[1]
Markscheme
arrow pointing at an epithelial cell ✔
Accept a bracket label to show the epithelium epithelial cell layer
(b)
Explain how the epithelial cells are adapted for absorption.
[2]
Markscheme
a. microvilli/brush border to increase surface area ✔
b. numerous mitochondria for energy for active transport ✔
c. have transport proteins for specific nutrients ✔
d. single layer of cells/short distance allowing for diffusion ✔
Explanation must be included for each characteristic eg: “glucose, amino acids”
