Why would your muscle cells need to be supplied with more food when there is a lack of oxygen than when there is plenty of oxygen present?

In order for your body to go through the life processed needed to live, you would need a source of energy to supply the "workers" for the task. It his case the source of energy is good since many different organic and inorganic materials can enter the cell after being digested, if necessary, to create the energy needed.

1.fossils 2.analogous organs 3.homologous organs