What is essential for transport of oxygen in red blood cells?

Iron reacts with oxygen to produce iron oxide (rust). this reaction is represented in an equation as 4fe + xo2 → 2fe2o3. identify the value of x that will balance the equation.

The intervention of extraterrestrials has been used to explain the bermuda triangle, a region of the atlantic ocean where ships and planes are frequently lost, leaving no evidence behind. how would this explanation best be characterized?

Aristotle classified animals according to their a. habitat and mating behavior c. mating behavior and relatedness b. habitat and physical differences d. physical differences and mating behavior