Question

Which one has a perforated wall?
A. Tracheid
B. Vessel
C. Fibre
D. Sclereid

Answer 1

Hint: Plants are made up of various types of cells. Cells of similar structure and function are grouped to form tissues. Each of the components of tissues have different structures to bring about the maximum utilization of resources. Some have thick lignified walls or perforated walls or thin walls that help the tissues to perform their designated function efficiently.

Complete answer:
Option (a) is incorrect. Tracheids are a part of the xylem tissue of a plant. Thus, tracheids are only present in vascular plants. The tracheids have lignified walls that are devoid of perforation plates. Apart from transportation of water from roots, tracheids also provide structural support to the plant.
Option (b) is correct. Vessel elements are a part of the xylem tissue of plants. Vessel elements are found only in angiosperms or flowering plants. These cells originate from the vascular cambium and are very efficient in transporting water from the root to different parts of the plant. The cell walls of the vessel elements are lignified in nature with pit-like structures present on the cell walls. These structures are called perforations that connect vessel elements to form a continuous and tubular structure.
Option (c) is incorrect. Fibres are a type of sclerenchyma cells. They are slender and elongated cells with hard, thick lignified walls composed of cellulose and hemicellulose. These cells are dead cells and their principal function is providing mechanical support to the plant. Fibres are used to make fabrics and are thus of immense economic importance.
Option (d) is incorrect. Sclereids are a type of sclerenchyma. They are the reduced form of sclerenchyma with very hard and lignified cell walls. They provide mechanical support to the plant.

Hence, the correct answer is option (B).

Note: Cells of plants that have perforated walls are vessel elements. These cells form a part of the xylem tissues and are therefore responsible for conduction of water. The perforations on the walls of the vessel elements are interconnected and have different shapes. Vessels are found in angiosperms and absent in gymnosperms.