What is the difference between an artery and a vein? 1 An artery carries blood away from the heart; a vein carries blood to the heart.
2 An artery is responsible for carrying blood; a vein is responsible for gas exchange.
3 An artery is responsible for gas exchange; a vein is responsible for carrying blood.
4 An artery carries blood to the heart; a vein carries blood away from the heart.

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.