Definition:
"Animals exhibit variations in the form, structure or composition of the chain of cuboidal cells which form a central lumen lined by microvilli that allow the passage of food, compared to control. Food passes from the posterior pharynx to the intestine where it is digested and then on to the rectum which processes the waste products for excretion (Wormatlas)." [WB:
WBPerson2021, WB:
WBPerson557]