second challenge to life on land was the distribution of water and other materials to each cell. In aquatic forms, transport occurs directly from the surrounding environment. On land, however, plants must get water and other materials from the soil.Body support
As plants evolved from aquatic to terrestrial environments, several obstacles stood in the way. One obstacle was structural support. In water, organisms are buoyant and the effects of gravity are minimal. Even among larger forms, like kelps, structures with gas-filled vesicles allow them to float. On land, however, if a plant is to grow tall, it needs to withstand the forces of gravity.
A third challenge during the transition to land involved bringing sex cells together. In water, sperm are able to swim directly to eggs. On land, this can only happen in moist environments.
hope this helps xxx
please get back to me if you need any other help or an explanation.
