Salmon returning to spawn in their native stream undertake a journey that requires extreme endurance.An examination of the muscles used to perform this activity would reveal
A) mostly smooth muscle fibers.
B) a high number of gap junctions.
C) mostly glycolytic fibers.
D) many mitochondria per cell.
E) pale color of the cells

Question

Quizplus · Accepted Answer

The extreme endurance required for salmon to return to their native stream to spawn suggests that they have muscles with a high capacity for oxidative metabolism, which is supported by the presence of many mitochondria in each cell. This enables them to sustain prolonged activity for long distances. The other choices - smooth muscle fibers, gap junctions, glycolytic fibers, and pale color of the cells - do not match the characteristics of musculature supportive of prolonged endurance exercise.

Salmon Returning to Spawn in Their Native Stream Undertake a Journey