In an electromyography (EMG) read out, all motor units can look slightly different because:. a. every muscle has a varying number of motor units so they can generate different frequencies.
b. every muscle has a varying number of motor units so they can generate different frequencies.
c. each motor unit can generate a different amount of recruitment. each motor unit can generate a different amount of recruitment.
d. every muscle has one motor unit so they have slightly different frequencies. every muscle has one motor unit so they have slightly different frequencies.
e. each motor unit can innervate a different number of muscle fibers. each motor unit can innervate a different number of muscle fibers.

a. every muscle has a varying number of motor units so they can generate different frequencies.

e. each motor unit can innervate a different number of muscle fibers.

Explanation:

Electromyography (EMG) is a diagnostic procedure used to measure the response of muscles and nerves to electrical activity. A motor unit is composed of one motor neuron and muscle fibers it innervates. The number of muscle fibers in each motor unit can vary among different muscles and even among motor units within the same muscle. Each motor unit is known to innervate a variable number of muscle fibers, but each single muscle fiber is innervated by only one motor.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.