Why is Blood Red?

The video explores why human blood is red, focusing on the role of red blood cells (RBCs) and hemoglobin. It explains that RBCs are abundant in blood and contain hemoglobin, a protein rich in iron that binds oxygen, giving blood its red color. The video also touches on the different blood colors in animals due to various pigments, such as hemocyanin in crabs and billiverdin in skinks. It concludes by encouraging viewers to donate blood and save lives.

What new insight or understanding did you gain from this video?