The answer is chlorophyll.
The right answer is surprisingly E.
Quinones, flavoproteins, cytochrome c, and electrons are important elements, essential for the respiratory chain.
Oxygen in respiration plays a role of final acceptor of electrons (and turns into H2O), but there are other final acceptors of electron transport depending on the species (nitrates for Pseudomonas, Sulphites for Clostridium ...). This allows us to classify respiration in two: aerobic respiration (with oxygen) and anaerobic respiration (without oxygen but with another electron end acceptor).
The electrode is Magnesium. Mg(s). During the operation some of the Mg atoms turn into Mg2 ions and go into the solution.
All of the above
Differentiation and specialisation are basically the same thing, and are caused because differences in gene expression cause different proteins to be produced that make up different types of cells. This also allows for development- for example as you get older a different genes are expressed to make your hair go gray
Let me know if you have any questions!