The answer is; glycolysis
This process converts glucose molecule to pyruvate. It is an oxygen-independent pathway, unlike the Krebs cycle. Glycolysis occurs in the cell cytoplasm while the Krebs cycle (aerobic pathway) occurs in the mitochondria. In the presence of oxygen, the product of glycolysis, i.e pyruvate, is fed to the Krebs cycle. If oxygen is unavailable the pyruvate is converted to lactate.
Malignant tumors are classified according to the type of cells that give rise to them.
The main reason for the difference in the mass extinction occurring today and previously is the pace of the current extinction. The extinction is taking place globally and involves hundreds of species at the same time. In less than 50 years, we have lost numerous species. In contrast to this, previously during the mass extinction, only a few species were lost, and other managed to survive. But, not the status is opposite due to the magnitude of the extinction.
