In my opinion i think the main events of glycolysis. how many atp molecules are produces and consumed by glycolysis? what effect does the presence of oxygen have on the events that follow glycolysis?

Glycolysis uses 2 ATP and produce 4ATP. So the net gain is true.

Oxygen is used in the Electron Transport Chain as the final electron recipient from complex 4 cytochrome a₃.

Explanation:

Glycolysis is the process which is common in all forms of respiration where glucose is metabolized into pyruvate. This process is very essential to continue the next steps of different respiration. Glycolysis requires 2 molecules to process substrate level phosphorylation to convert glucose to glucose 6 phosphate and fructose 6 phosphate to fructose 1, 6 bisphosphate. But it produces 4 ATPs. Thus net gain is 2ATP.

In ETC, the hydrogen carriers NADH and FADH gives off the hydrogen to reduce the complex 1 and 2 respectively and itself gets oxidized. Thus the electron given off is transferred between 4 complexes to finally give off to oxygen to form water.

as in mitosis, dna replication occurs during interphase.   in meiosis, it occurs specifically in s phase of interphase 1.