Answer:
four oxygen molecules
Explanation:
The hemoglobin molecule has four binding sites for oxygen molecules: the iron atoms in the four heme groups. Thus, each Hb tetramer can bind four oxygen molecules.
Biology is the study of natural science (nature) and it is important to humans cause we learn about it
<span>D) They are nonlobed, simple leaves and are attached oppositely on the branch.</span>
the temperature will start to rise and it is probably becoming sunny
