Q32 — Shiverer Mutation — Optic Nerve Myelin
The shiverer mutation is known to affect the Central Nervous System (CNS), causing tremors and early death in mice. To investigate its effects, the optic nerve — which, unlike all other nerves, is histologically equivalent to the CNS — was cut transverse and stained for lipids (A – wild type, B – mutant).
Transverse optic nerve cross-sections stained for lipids: A — wild type, B — shiverer mutant.
Using the information and image, determine whether the following statements are true or false:
A. Picture A contains multiple Schwann cells.
B. Ion channels of neurons in Picture B were directly affected by the mutation.
C. The shiverer mutation severely compromises oligodendrocytes.
D. In Picture A we could see the nucleus in place of the asterisk, if we stained the sample with DAPI.
Question reproduced from IBO 2022, Theoretical Paper 1, licensed under CC BY-NC-SA 4.0 — attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)