Final answer:
The gritty texture in pears is caused by small, thick-walled cells called sclereids, a type of sclerenchyma cell.
Step-by-step explanation:
The gritty texture in pears is due to the presence of sclereids, which are a type of sclerenchyma cells. These cells, unlike their counterparts, collenchyma cells, are often dead at maturity and have thickened secondary cell walls with deposits of lignin, an important component of wood. While fibers are elongated cells, sclereids are smaller and are responsible for the characteristic gritty texture found in pears. In addition to their role in plants, humans utilize sclerenchyma fibers in the production of items such as linen and rope.