Answer:
Aa
Explanation:
AA or Aa → Enough normal enzyme to make melanin in skin and hair → Normal skin and hair color aa → Defective enzyme for melanin production → Very pale skin and hair color (albino) Page 3 2.
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.
It refers to Calorific flow