Final answer:
Hard mechanical texture necessitates grinding with molars, which is a part of mechanical digestion occurring in the mouth and stomach to prepare food for chemical digestion.
Step-by-step explanation:
The texture characterized by a hard exterior that needs grinding/rotary chewing to break apart is called hard mechanical. This type of texture typically requires the use of molars for mechanical digestion, which is the physical process of breaking down food into smaller pieces without changing its chemical structure. Mechanical digestion includes mastication (chewing), and it occurs mainly in the mouth and stomach, where food is prepared for chemical digestion.
The act of chewing, especially with molars, is central to mechanical digestion. Molars are broad and flat, designed specifically for crushing and grinding foods such as nutmeats into a pulp. This preparatory phase of digestion enhances the surface area and mobility of the food, facilitating subsequent chemical digestion wherein nutrients are broken down and absorbed.