Correct Option
The correct option is (a) 1 only.
Explanation
In plants, permanent tissues are classified into simple (Parenchyma, Collenchyma, Sclerenchyma) and complex tissues. Aquatic plants (hydrophytes) exhibit specific anatomical adaptations to survive in water, primarily involving modifications in their simple permanent tissues to provide buoyancy.
Statement-wise Analysis
- Statement 1 is Correct. Aquatic plants require buoyancy to float on or near the water surface. This is achieved through the presence of large air cavities within the plant tissues. These cavities store gases and provide the necessary lift. Although the question prompt refers to the "Epidermis," the description in this statement accurately identifies the functional adaptation (air cavities) found in the parenchymatous tissue of aquatic plants.
- Statement 2 is Incorrect. The modified tissue containing large air cavities is not Sclerenchyma. Sclerenchyma consists of dead cells with thick, lignified walls (e.g., coconut husk) and provides hardness, stiffness, and mechanical strength, not buoyancy.
- Statement 3 is Incorrect. Aerenchyma is a specialized type of Parenchyma, not Collenchyma. Parenchyma cells modify to form Aerenchyma in aquatic plants. Collenchyma is a living mechanical tissue characterized by unevenly thickened cell walls (pectin and cellulose) that provides flexibility and support to growing parts of the plant.
Key Takeaway
Aerenchyma is a modified form of Parenchyma tissue found in aquatic plants. It possesses large air cavities that provide buoyancy, allowing the plants to float.