Phenotype
Genotype makes up the genetic constitution of an individual. (Cannot observe with the naked eye)
Cell membrane - the thin layer of protein and fat that surrounds the cell, but is inside the cell wall. The cell membrane is semipermeable, allowing some substances to pass into the cell and blocking others.
Ileocecal sphincter tone decreases after distention of colon. This sphincter separates ileum and cecum and is under the control of vagus nerve.
