Question

The main purpose that the aerenchyma serves in Parenchyma is ____.

• A. Offers flexibility
• B. Renders Buoyancy
• C. Provides structural framework
• D. Provides mechanical support

Hint:

To connect the word to its function, look at the name: "Aer-" stands for Air. The tissue acts exactly like a built-in life jacket or swim bladder filled with air, keeping the aquatic plant floating effortlessly.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Parenchyma cells can adapt their internal spacing and structure to match the specific physiological demands of their environment, such as aquatic living conditions.

Step 2: Detailed Explanation:
Aerenchyma is a modified form of parenchyma tissue found predominantly in hydrophytes (aquatic plants like Lotus and Hydrilla). In this tissue, the cells arrange themselves to surround unusually large, interconnected internal air cavities or spaces. These hollow pockets trap gases and air, which provides buoyancy to the plant, helping its leaves and stems float on or near the water's surface to maximize sunlight absorption for photosynthesis.

Step 3: Final Answer:
The main purpose of aerenchyma is to render buoyancy to aquatic plants.

Answer 2

Aerenchyma is a parenchyma modification found mainly in water-dwelling plants, and each option describes a different possible physical benefit; matching the tissue's actual structure (large air-filled cavities) to the right benefit will identify the correct purpose.

1. Offers flexibility: Flexibility in plant tissue usually comes from having living cells with only slightly or unevenly thickened walls (as in collenchyma), not from the presence of large air spaces, so this is not the primary role of aerenchyma.
2. Renders Buoyancy: Aerenchyma cells are arranged around large interconnected air spaces that trap gas within the tissue. This trapped air reduces the overall density of the plant part, allowing leaves and stems of aquatic plants like lotus and hydrilla to float on or near the water surface, which keeps them close to sunlight for photosynthesis. This buoyant function is exactly what the large air cavities are built for.
3. Provides structural framework: A structural framework role is generally associated with tissues that have solid, thickened cell walls; aerenchyma's defining feature is the opposite, large hollow spaces, which would weaken rather than reinforce a rigid framework.
4. Provides mechanical support: Mechanical support against physical stress is the job of tissues like collenchyma and sclerenchyma, which have thickened walls; aerenchyma's air-filled design trades away structural strength in favour of buoyancy.

Since the tissue's defining large air cavities directly reduce density rather than add strength or rigidity, its purpose is clearly linked to floating.

Therefore, the correct answer is Renders Buoyancy.