This is why natural selection acts on phenotypes instead of genotypes. A phenotype is an organism's physical traits, while a genotype is an organism's genetic makeup. This may sound counter-intuitive since the genetic makeup does get<span> passed on from generation to generation through reproduction.</span>
A simple example is a connection between the circulatory and respiratory systems. <span>As </span>blood<span> circulates through your body, it eventually needs fresh oxygen </span><span>from the air. When the </span>blood<span> reaches the lungs, part of the </span>respiratory system<span>, the </span>blood<span> is re-oxygenated.</span>
a
due to the comedy of the Earth and beautiful hydration of the earth beneath
Im thinking C. The skeletal system but not 100% sure.
