JAMB - Biology (2001 - No. 43)
The stem of a typical aquatic plant usually has many
air cavities
intercellular space
water cavities
water conducting cells
Explanation
Aquatic plants have large air cavities in their stems, leaves, and roots, which are called aerenchyma. Aerenchyma is a spongy tissue that creates air channels and gaps in the plant. These air cavities help the plant float and provide buoyancy.