Answer:
A wetland is a distinct ecosystem that is flooded by water, either permanently or seasonally, where oxygen-free processes prevail.[1] The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants,[2][3] adapted to the unique hydric soil
Only 1 to 2% of the sunlight reaching the earth is used by the plants to make sugars.
The sunlight that reaches the plants are distributed in many ways. Some of the sunlight are reflected by the green leaf, some are absorbed by the structural and non chlorophyll cells and only a small fraction of the sunlight is actually used to carry out photosynthesis.
The answer is semi-permeable!
Diffusion happens in living systems for example it explains the movement of carbon dioxide in leaves. Plants absorbs water from the soil by osmosis through their roots hair cell. Animals molecules enter the body cells and waste products are removed.
Friction is the force you are asking about or gravity or plate techtonics