Epithelial Tissue

Concept: Plant tissues are composed of cells that can be either living or dead at maturity, depending on their function. Step 1: Understanding different plant tissues
Parenchyma: These are simple permanent tissues composed of living cells with thin cell walls. They perform various functions like photosynthesis, storage, and secretion.
Meristematic tissues (Meristems): These are regions of actively dividing cells responsible for plant growth (e.g., at the tips of roots and shoots). Meristematic cells are living.
Sclerenchyma: This is a simple permanent tissue that provides mechanical support and strength to plants. Sclerenchyma cells are characterized by thick, lignified secondary cell walls. These cells are typically dead at maturity. Their primary function (support) is provided by their rigid cell walls, and they do not need to be metabolically active. Sclerenchyma includes fibers and sclereids (stone cells).
Companion cells: These are specialized parenchyma cells found in the phloem of flowering plants. They are living cells and are closely associated with sieve tube elements, providing metabolic support to them. Step 2: Identifying the tissue made of dead cells Based on the descriptions:
Parenchyma: Living cells.
Meristematic tissues: Living, actively dividing cells.
Sclerenchyma: Dead cells at maturity, providing structural support.
Companion cells: Living cells. Therefore, Sclerenchyma is the tissue made of dead cells among the options.

Step 1: Understand Epithelial Tissue Types.
Epithelial tissues are classified based on their shape and arrangement. The specific type of epithelial tissue that lines kidney tubules and ducts of salivary glands is ciliated columnar epithelium. This tissue is characterized by: Columnar cells: Tall, column-shaped cells that provide a large surface area for absorption or secretion.
Cilia: Hair-like structures on the free surface of the cells that help move substances along the surface (e.g., mucus in the respiratory tract).
Step 2: Analyze Each Option.
Option (1): Cuboidal epithelium — Incorrect, as cuboidal epithelium consists of cube-shaped cells and is not typically found in kidney tubules or salivary gland ducts.
Option (2): Stratified squamous epithelium — Incorrect, as stratified squamous epithelium consists of multiple layers of flat cells and is found in areas requiring protection, such as the skin and lining of the mouth.
Option (3): Ciliated Columnar epithelium — Correct, as this is the type of epithelium found in kidney tubules and salivary gland ducts.
Option (4): Glandular epithelium — Incorrect, as glandular epithelium is specialized for secretion and does not form the lining of kidney tubules or salivary gland ducts.
Step 3: Final Answer. $ $