Oligodendrocytes are cells in the brain that produce myelin in the central nervous system. Myelin regulatory factor (MyRF) is a transcription factor that is required by oligodendrocytes in order to produce myelin. Researchers investigated the importance of MyRF by having mice learn how to run on complex wheels (there were many gaps in the wheel thus making it difficult to run on-see graph below).

-Mice that lacked the MyRF genes (P-MyRF (−/−)) and mice that had functional MyRF genes (P-MyRF (+/−)) ran on the complex wheel and their speed was recorded (see accompanying figure). What group of mice learned how to run on the complex wheel more easily?
A) mice with nonmyelinated axons
B) mice with myelinated axons

Question

Oligodendrocytes are cells in the brain that produce myelin in the central nervous system. Myelin regulatory factor (MyRF) is a transcription factor that is required by oligodendrocytes in order to produce myelin. Researchers investigated the importance of MyRF by having mice learn how to run on complex wheels (there were many gaps in the wheel thus making it difficult to run on-see graph below).
 
-Mice that lacked the MyRF genes (P-MyRF (−/−)) and mice that had functional MyRF genes (P-MyRF (+/−)) ran on the complex wheel and their speed was recorded (see accompanying figure). What group of mice learned how to run on the complex wheel more easily?
A) mice with nonmyelinated axons 
B) mice with myelinated axons

Quizplus · Accepted Answer

Myelin is necessary for efficient transmission of neural signals, and oligodendrocytes produce myelin. MyRF is required for oligodendrocytes to produce myelin. Therefore, mice with functional MyRF genes (P-MyRF (+/−)) who can produce myelin more easily would learn how to run on the complex wheel more easily. Therefore, mice with myelinated axons learned how to run on the complex wheel more easily.

Oligodendrocytes Are Cells in the Brain That Produce Myelin in the Central