Without oxygen, organisms can just split glucose into two molecules of pyruvate.With oxygen, organisms can break down glucose all the way to carbon dioxide. This releases enough energy to produce up to 38 ATP molecules. Thus, aerobic-respiration releases much more energy than anaerobic respiration.That's what Respiration to generate engery.
The correct option is 3.
Enzymes are biological catalysts which speed up the rate of biochemical reactions inside the cells. Enzymes are very specific in action and they require specific conditions called optimum conditions for them to function optimally.
When the optimum conditions are not met, an enzyme's activity will be lowered or totally stopped.
Conditions that affect the optimum activity of an enzyme include: temperature, pH level and regulatory activity of regulatory enzymes and hormones.
Answer:
Porifera—gastrovascular cavity, coelomate.
Explanation:
Sponges do not contain digestive system but obtain nutrients through the diffusion process. Porifera is the most commonly asymmetrical in nature but can also have radial symmetry. Porifera has no coelom.
Lacking a true digestive system, they depend on the intracellular digestive processes of their choanocytes for their energy intake. Gas exchange, circulation, and excretion occur by diffusion between the water and the cells.
Reading background information because it gives ideas from the author himself.