Migrating Birds Often Cross the Gulf of Mexico in a Single

Multiple Choice

Migrating birds often cross the Gulf of Mexico in a single flight,and their flight muscles demand extreme endurance.An examination of the muscles used to perform this activity would show that they

A) have low reserves of glycogen (metabolic fuel) .
B) have high levels of ATPase activity.
C) are well-supplied with blood vessels.
D) have few mitochondria.
E) have low levels of myoglobin.