Red blood cells:To understand the adaptation, our first question is actually, what is the function of red blood cells- oxygen transportTherefore, if we want efficient oxygen transport:1)no nucleus- gives us more space to carry oxygen molecules (a red blood cell can carry up to 4!)2)high surface area- so diffusion is more efficient3)contains hemoglobin- a key molecule! this is the molecule that has an 'affinity' for oxygen- affinity is almost like an attraction to oxygen so it hugs the oxygen tightly