Understanding Human Blood Color

The video addresses the common misconception that human blood is blue. It explains that diagrams often use blue to represent deoxygenated blood, which can lead to confusion. The video clarifies that veins appear blue due to light absorption and reflection under the skin, not because the blood is blue. Human blood is red due to the presence of red blood cells containing hemoglobin, which binds oxygen. While oxygen-rich blood is brighter red, it remains red regardless of oxygen levels. The video also notes that while many animals have red blood, not all do.

Why do some people mistakenly believe that human blood is blue?

• Because veins appear blue under the skin

• Because of the color of the heart

• Because blood is blue when it lacks oxygen

• Because of the color of the skin

What is the role of hemoglobin in red blood cells?

• To clot the blood

• To fight infections

• To bind and transport oxygen

• To give blood its blue color

How does the oxygen content affect the color of human blood?

• Oxygen content does not affect blood color

• More oxygen makes blood appear brighter red

• Less oxygen makes blood appear green

• More oxygen makes blood appear blue

Which of the following statements is true about the color of human blood?

• Human blood is green under the skin

• Human blood is always red

• Human blood is blue when deoxygenated

• Human blood changes color with temperature

Do all animals have red blood?

• No, only mammals have red blood

• No, not all animals have red blood

• Yes, but only when oxygenated

• Yes, all animals have red blood