Describe two paths carbon dioxide can take through the carbon cycle.

When animals undergo the process of cellular respiration, they release carbon dioxide into the atmosphere. When animals die and start to decay aided by organisms called decomposers, carbon dioxide is also emitted into the atmosphere. When humans burn fossil fuels, carbon dioxide yet again enters the atmosphere. 

Wetlands form where water and land meet. a lake with a wetland fringe can fill in with decayed plant and animal material to become a wet meadow. a pond can fill in to become a bog or fen. sediment can fill in a river marsh to become a swamp.flooding of coastal lowlands from rising sea levels has created broad coastal marshes that are protected from wave action by barrier islands or reefs. coastal wetlands also form when rivers deposit sediment as they reach the ocean. plants then take root and hold the soil firm against the forces of tides and waves.

The arrangements of lipids in the membrane makes the cell semi permeable .