AP BIOLOGY

Detailed explanation-1: -Sclerenchyma cells form the permanent tissue in plants. Sclerenchyma is composed of dead cells, therefore they form a stiff and hard layer. Sclerenchyma is present mainly around the vascular bundle in the veins of leaves. They form a hard covering around the seeds and nuts.

Detailed explanation-2: -They are commonly found in soft tissues, e.g. cortex, phloem, the pulp of fleshy fruits, fruit walls and seed coats. They are found in shells of nuts, fruit pulp of pear, guava, etc., tea leaves and seed coat of legumes. They provide structural support and mechanical strength to plant organs.

Detailed explanation-3: -Assertion: Sclereids are found in fruit walls of nuts, pulp of fruits like guava, pear and sapota and seed coats of legumes. <br> Reason: Sclereids are spherical, oval or cylindrical, highly thickened dead cells with narrow lumen.

Detailed explanation-4: -They often occur in bundles or strands and can be found almost anywhere in the plant body, including the stem, the roots, and the vascular bundles in leaves.

Detailed explanation-5: -Hard and stony shells of fruits and seed coats are characterized by the presence of sclereids which is a type of sclerenchyma tissue. The cells of sclereids are highly thickened and possess lignified cell wall which is responsible for the hardness of fruits and seed coats.