Question

Grittiness of pear fruit is caused by
A. Sclereids
B. Raphides
C. Collenchyma
D. Dead parenchyma cells

Answer 1

Hint: Pear are commonly produced fruit produced around the world and they are harvested in the summer months up to October. The pear tree belongs to the species of genus Pyrus in the family Rosaceae.

Complete answer:
Pear are the trees and shrubs that bear pomaceous fruits which are known as the pear. The tree is medium in size and it is native to the coastal and mildly temperate regions of Europe, North Africa and Asia. The fruit is composed of the upper end of the flower stalk and is known as the calyx tube. The fruits are fleshy and contain a core. The flesh of the fruit exhibits a grittiness which is due to the presence of sclereids or stone cells.
-The sclereids are reduced sclerenchyma cells. They are the cells with highly thickened, lignified cellular walls. These cells form the small bundles of tough durable layers of tissues in the plants. Due to the numerous number of sclereids present in fruits like pear, the flesh of the fruit has a distinct grittiness. The sclereids are in general isodiametric, forked or are elaborately branched and are grouped into bundles. They are found in the epidermis, ground tissues and vascular tissues.
-Raphides are crystals of needle shaped and are made up of calcium oxalate or calcium carbonate. They are found in specialized plant cells or crystal chambers which are known as idioblasts.
-Collenchyma are the tissues that are composed of elongated living cells of uneven primary thick walls. It provides structural strength, flexibility to the petiole, leaves and the stem in young plants.
-Dead parenchyma cells are mature cells which arise from the thin walled cells and make the photosynthetic tissues in plants, pulp of fruits and endosperm of the seeds.

Hence, the correct answer is option (A).

Note: Pear is a pomaceous fruit and belongs to the family of Rosaceae. The flesh of the fruit bears a grittiness which is due to the presence of sclereids in the flesh of the fruit. Sclereids are also known as stone cells and are sclerenchyma cells.