1. Which of the following represents the CORRECT order of eventsin a motor neuron when I decide that I want to wiggle myfinger?

A. An action potential reaches the end of the motor neuroncausing the influx of calcium through ligand-gated calcium channelsand the fusion of vesicles containing acetylcholine with thepresynaptic membrane

B. An action potential reaches the end of the motor neuroncausing the influx of calcium through voltage-gated calciumchannels and the fusion of vesicles containing acetylcholine withthe presynaptic membrane

C. An action potential reaches the end of the motor neuroncausing the influx of sodium through ligand-gated sodium channelsand the fusion of vesicles containing acetylcholine with thepresynaptic membrane

D. An action potential reaches the end of the motor neuroncausing the influx of sodium through voltage-gated sodium channelsand the fusion of vesicles containing acetylcholine with thepresynaptic membrane

2. During endochondral ossification, osteoblast is derived fromwhich cell type?

A. Articular cartilage

B. Fibroblast

C. Chondrocytes

D. Mesenchymal stem cells

3. Which of the following is TRUE about muscle contraction?

A.Hydrolysis of ATP to ADP and Pi “cocks” the myosin head to ahigh energy state

B.Rigor mortis (continued contraction) occurs when there is anexcess of ATP binding to the myosin head.

C.The binding of ATP to the myosin head causes myosin heads tobind to actin.

D.Each cycle of the sliding filament model (Cross-bridge cycle)leads to lengthening of the sarcomere