Question

The branched sclereids present in hydrophytes are
A.Osteosclereids
B. Trichosclereids
C. Macrosclereids
D. Astrosclereid

Answer 1

Sclereids are highly condensed dead sclerenchyma cells with very thin cavities. They may also be branched. They contribute stiffness to the parts in which they occur. Sclereids are of several types, these include- brachysclereids, macrosclereids, osteosclereids, astrosclereids, trichosclereids, and filiform sclereids.

Complete answer: Option A- Osteosclereids: Osteosclereids is also known as bone cells. It is a type of sclereid, formed at the hypodermal layer in seeds, fruits, and leaves of some plants (dicots). It was first detected in the seed coat of Pisum during the maturation. These are the columnar cells that are dilated at the ends.
Option B- Trichosclereids: Trichosclereids refers to hard needlelike branched cells found in some species of plants. They fulfill the objective of conserving the plant from herbivores. They usually are nearly 6 mm long, but in some species, they grow to as long as 1 cm.
Option C- Macrosclereids: Macrosclereids refers to rod-shaped sclereids. They are generally found on the outer layer of the seed coat. They have very heavy secondary walls and there is practically no lumen. Examples of plants where Macrosclereids are found- leguminous plants like peas, beans, and lentils.
Option D- Astrosclereids: Astrosclereids refers to branched, pointed, irregular (often star-shaped) sclereids. Astrosclereids are not a widespread type of sclereid. They are only found in specialized tissues like the floating leaves of water lily.
So, the correct Option is D- Astrosclereids

Note: Sclereids refers to a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls. They form small bundles of durable layers of tissue in maximum plants. The existence of several sclereids from the cores of apples and generate the gritty texture of guavas.