DP Biology (last assessment 2024)
Question 19N.2.HL.TZ0.5b
Date | November 2019 | Marks available | [Maximum mark: 2] | Reference code | 19N.2.HL.TZ0.5b |
Level | HL | Paper | 2 | Time zone | TZ0 |
Command term | Discuss | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19N.2.HL.TZ0.5b
This light micrograph shows skeletal muscle.
[Source: adapted from https://en.wikipedia.org/wiki/Skeletal_muscle#/media/File:Skeletal_
muscle_%E6%A8%AA%E7%BA%B9%E8%82%8C1.JPG, Urana/ 乌拉跨氪]
(b)
Discuss whether the tissue shown in the micrograph consists of cells or not.
[2]
Markscheme
a. «muscle fibres are» multinucleate/contain many nuclei «whereas cells are expected to have only one/so muscle fibers are an exception to the cell theory» ✔
b. one cell membrane/sarcolemma enclosing a whole muscle fibre «as expected for cells» ✔
c. very large/much larger/longer/than most cells ✔
d. muscle fibres formed by fusion of cells/are syncytia ✔
