Tall land plants have requirements different from those of aquatic plants. Which of these must tall land plants have that aquatic plants do not need?

Tall land plants require thick-celled walls primarily for support and to maintain their structure. Unlike aquatic plants, which are buoyed by water and do not need such robust cell walls to support their weight, terrestrial plants must withstand the forces of gravity. The thickness of the cell walls in land plants allows them to stand upright and resist external pressures, like wind.

In addition to structural support, thick-celled walls also help land plants minimize water loss in a terrestrial environment, which can be crucial for their survival. On the other hand, water supports aquatic plants, alleviating the need for such thickened cell structures.

Other choices, such as stomata for gas exchange and chlorophyll for photosynthesis, are also necessary for both land and aquatic plants, while aerial roots are not a universal requirement for all tall land plants.