DP Biology (last assessment 2024)
Question 18N.3.HL.TZ0.2
| Date | November 2018 | Marks available | [Maximum mark: 5] | Reference code | 18N.3.HL.TZ0.2 |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Calculate, Describe, Label | Question number | 2 | Adapted from | N/A |
2.
[Maximum mark: 5]
18N.3.HL.TZ0.2
The micrograph shows a section through the root of a dicotyledonous plant (× 400).
(a)
Label tissues X and Y.
[2]
Markscheme
a. X: phloem ✔
b. Y: xylem ✔
(b)
Calculate the actual width along line A-B of the parenchyma cell shown.
[1]
Markscheme
A-B =
OR
17.5 μm ✔
Accept answers in the range of 17 to 19 μm
(c)
Describe the distribution of vascular tissues in the stem of dicotyledonous plants.
[2]
Markscheme
a. stem vascular tissue is in bundles ✔
b. «bundles» form a ring
c. phloem is towards outside «of bundle»
OR
xylem is towards centre «of bundle» ✔
Allow answers in an annotated drawing
