Question

Uneven thickened primary walls with elongated cells is called ____.

• A. Collenchyma’s tissues
• B. Phloem tissues
• C. Xylem tissues
• D. Parenchyma tissues

Hint:

Key structural markers to differentiate simple permanent tissues at a glance: - Parenchyma: Uniformly thin walls (living). - Collenchyma: Unevenly thickened primary walls at corners (living). - Sclerenchyma: Uniformly highly thickened lignified secondary walls (dead).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Simple permanent tissues are classified as parenchyma, collenchyma, or sclerenchyma depending on the nature of their cell wall depositions and cell vitality.

Step 2: Detailed Explanation:
Collenchyma tissue consists of living, elongated cells with primary cell walls that show uneven thickening, particularly localized at the corners. This heavy localized deposition is made up of cellulose, hemicellulose, and pectin. Because it consists of living cells with localized flexible thickening, collenchyma provides mechanical support and elasticity to young, growing plant organs (like petioles and young green stems) without restricting their expansion.

Step 3: Final Answer:
Cells with unevenly thickened primary walls are characteristic of Collenchyma tissues.