Question

the wall of the gut tube has layers of smooth muscle that run both circularly and longitudinally. the contraction of these muscles produces
deglutition.
defecation.
peristalsis.
mastication.

Explanation:

• Deglutition is swallowing, involving throat muscles, not gut smooth muscle layers.
• Defecation is the final elimination step, not the general contraction product of gut muscle layers.
• Peristalsis is the wave-like movement caused by alternating contraction of circular and longitudinal smooth muscle layers in the gut tube, moving food through the digestive tract.
• Mastication is chewing, done by skeletal muscles in the mouth.

Answer:

peristalsis.