DENDROLOGY

Detailed explanation-1: -Glycolysis, which is the first step in all types of cellular respiration is anaerobic and does not require oxygen. If oxygen is present, the pathway will continue on to the Krebs cycle and oxidative phosphorylation. However, if oxygen is not present, some organisms can undergo fermentation to continually produce ATP.

Detailed explanation-2: -Glycolysis, lactic acid production (lactate fermentation), and fermentation are all processes that do not require any oxygen. These can occur without the presence of oxygen.

Detailed explanation-3: -Therefore, without the presence of oxygen, glycolysis is the only process that can occur, and only two ATP molecules may be produced for each glucose molecule.

Detailed explanation-4: -In organisms that perform cellular respiration, glycolysis is the first stage of this process. However, glycolysis doesn’t require oxygen, and many anaerobic organisms-organisms that do not use oxygen-also have this pathway.