Alveolar walls are thin to enable the quick passage of oxygen in and out of the lungs. The lungs works hand-in-hand with the heart and also is responsible in converting blood that's de-oxygenated into an oxygenated blood that is usable by the organ systems of the body. The alveolar walls are also designed to have thin membranes so that it can expand and constrict quickly allowing us to breather properly.
Answer:
The correct answer is - per gram, the marathon runner's muscles would contain more myoglobin than the sprinter's muscles.
Explanation:
Marathon runners have smaller leg muscles and thinner quads and calves as marathon runners require slow-twitch muscles while in sprinters the fast-twitch muscle requires. Slow-twitch muscles of marathon runners have more amount of myoglobin, per gram than fast-twitch muscles.
Myoglobin acts as local oxygen storage that provides oxygen to the muscles in case of less oxygen supply than required temporarily and a marathon race is an intense exercise or activity that requires more oxygen.
One of the major elements of natural selection is that all species have genetic variation. Natural selection is a process when organisms adapt better to their environment. It is an essential key in evolution. There is a change in phenotype of a population over time.
House sparrows in the northern part of North America are larger than those found in the southern regions. The possible mechanism of microevolution is more likely to be responsible for this is natural selection. The answer would be letter B.
When your body turns your food into energy it can heat your body which is called cellular respiration. Not sure if this is what you were looking for?