Question

Which one is made of dead cells :

• A. Parenchyma
• B. Meristematic tissues
• C. Sclerenchyma
• D. Companion cells

Hint:

In plants:
{Living tissues} for growth, photosynthesis, storage: Parenchyma, Collenchyma, Meristems, Phloem (sieve tubes need companion cells).
{Dead tissues} for support and water transport: {Sclerenchyma} (fibers, sclereids) and Xylem vessels/tracheids. Sclerenchyma cells have very thick, hard walls that provide strength, and they are dead when they perform this function.

Answer 1

The Correct Option is C

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.