Question

Identify the incorrect statement about a single motor unit.- Fine motor skills depend on the development of small motor units.- The smaller the number of muscle fibers, the more precise the movement.- Muscle fibers of one motor unit intermingle with the fibers of another motor unit.- Some motor units include as many as 2000 muscle fibers.- The more neurons involved, the more powerful the contraction.

Answer 1

The following is a list of the events that occur during a muscle contraction. What is the correct sequence of these events?

1. Myosin cross-bridges bind to the actin.

2. The free myosin head splits ATP.

3. Calcium ion is released from the sarcoplasmic reticulum.

4. The myosin head pivots toward the center of the sarcomere.

5. Calcium ion binds to troponin.

6. The myosin head binds an ATP molecule and detaches from the actin.