Answer:
The toughest cuts have a lot of connective tissue and come from a heavily exercised muscle. (Exercise increases the amount of connective tissue within the muscles, making them tougher.) The tenderest cuts are those that have very little connective tissue and come from a little-used muscle.
Explanation:
Fundamentally, tender meats come from an animal's weaker muscles, or any relatively low-activity muscles that have fine-textured muscle fibers with relatively weak collagen. Poultry breasts, beef tenderloin, pork chops, and lamb racks are all considered tender meats.
