The answer is artery.
A blood vessel with a thick layer of smooth muscle and elastic fibers is artery. Even though both artery and veins are smooth muscle and elastic fiber. The difference is veins have valves, while arteries don't.
Explanation:
The cellular communication is an important aspect of unicellular and multicellular organisms in the environment. The cellular communication may differ in the bacteria, plants and animals but the mechanism of cellular communication remains the same.
The mechanism involves the receptors, change in the structure of receptors which triggers the signal to respond and then the response of the cell. Therefore the evolutionary biologists must look at this mechanism and the molecules associated with this mechanism.
The biologist can look at these receptors and the ligands which initiate the transduction process in the organisms.
Is known as Phloem. Its counterpart Xylem helps to transport water
The oxygen cycle can be found in all but the geosphere. There's oxygen in the atmosphere, so it has to be there, and the biosphere includes living things, which breathe oxygen, and water (hydrosphere) is made up of partly hydrogen, so there has to be oxygen there as well.
