Answer:
B. The available donors and acceptors will induce gene expression of their redox enzymes, thereby allowing their use
Explanation:
Electron transport chain is the important stage of cellular respiration where the electron is donated by certain redox molecules.
The ETC takes place in both the aerobic and anaerobic type of respiration wherein the aerobic respiration, oxygen is used as the electron acceptor whereas in the anaerobic respiration some other molecules like sulfate and nitrate are used.
In anaerobic respiration, the type of electron donors and the donor-acceptor molecules determine the fate of the chain as these molecules act as an inducer of the genes of redox enzymes and the genes for the enzymes are expressed.
Thus, Option-B is correct.
Answer:
Oxygen was not present on early earth
