In aquatic plants, large air sacs give them buoyancy effects. These sacs are surrounded by which one of the following types of tissues?

In aquatic plants, buoyancy is provided by a specialized tissue known as aerenchyma. Aerenchyma is a modified form of parenchyma tissue characterized by large air sacs or intercellular cavities [1]. These air spaces facilitate the exchange of gases and provide the necessary buoyancy for plants to float or remain upright in water. While parenchyma is a versatile ground tissue that typically acts as 'filler' in soft plant parts, its adaptation into aerenchyma is specific to hydrophytes [1]. In contrast, collenchyma provides mechanical support to growing parts, and sclerenchyma consists of dead cells with lignified walls for structural rigidity [1]. Since aerenchyma is composed of parenchyma cells with large air cavities, the sacs are surrounded by parenchymatous tissue [1].

Sources

1. [1] https://en.wikipedia.org/wiki/Ground_tissue