Answer:
A. If the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt."
D. The rate of energy demand determines how the muscles will obtain energy, either from cellular respiration or from lactic acid fermentation if not enough oxygen is present.
Explanation:
It is important to consider that Kenny hikes all day but at a steady pace, whereas Janelle runs very fast. So Kenny's case, the supply of oxygen is sufficient to maintain aerobic respiration within the muscle cells. During this process only CO2, Water, and ATP are produced; therefore, there is no oxygen debt. We should keep in mind that the body shifts to anaerobic metabolism only when the supply of oxygen is limited.
In Janelle's case, running fast would need energy at higher rates and the supply of oxygen would not be sufficient to generate a high amount of ATPs. Therefore, to compensate for this deficiency, cells will start fermenting glucose to lactic acid and produce ATP and maintain energy demands. This lactic acid causes fatigue and this is why Janelle has aching and breathing hard. Breathing hard is also automatic reflux to inhale more oxygen and meet oxygen demands but even breathing hard would not be able to make it and the body will shift to anaerobic respiration automatically.
C. testable and observable
During ecological succession of an ecosystem new organisms begin to grow and the ecosystem begins to recover. This is the way ecosystems repair themselves after a disaster.
<span>specialized cells, thats what bone and blood cells are considered </span>
In plants, photosynthesis, occurring in chloroplasts, is an anabolic (bond-building) process whereby CO2 and H2O combine with the use of light (photon) energy. This yields O2 and sugar (i.e. glucose). This occurs in 2 phases: light-dependent and dark (Calvin cycle) reactions, which both continually recycle ADP/ATP and NADP/NADPH.
The catabolic (bond-breaking) process in plants is cellular respiration, in which glucose is broken down with O2 by glycolysis (cytoplasm only) and mitochondrial reactions (Krebs cycle and E.T.C.) to yield CO2 and H2O. These reactions recycle ADP/ATP and NAD/NADH. The CO2 and water produced by cellular respiration feed into the photosynthetic processes, and in turn, the O2 and glucose resulting from photosynthesis supply the respiratory reactions.
