B)
Because it flows. I dunno about you, but that sounds like a liquid to me! Sorry if i'm wrong.
The term that refers to all areas of Earth where all life exists is call the Biosphere
The final acceptor of electrons in the electron transport chain is "C" , that is oxygen.
The electron transport chain is composed of a series of electron carriers that operate together to transfer electrons from donors, like NADH and FADH2, to acceptors such as O2.
The electrons flow from carriers with more negative reduction potentials to those with more positive potentials and eventually combine with O2 and H+ to form water.
The difference in reduction potentials between oxygen and NADH is large, about 1.14 volts and makes possible the release of a great deal of energy.
True... is this the question or...
Building models doesn't actually help scientists observe phenomena. Scientists build models to describe how nature and systems operate then make observations to see if their models match what they observe. Models which don't match what they observe are either alterated or scrapped. Good models are kept and used by the scientific community.
