Bonjour,
1. Arteries carry blood from the heart to the rest of the body, whereas veins carry blood from the rest of the body back to the heart.
2. Almost all arteries carry oxygenated blood and almost all veins carry deoxygenated blood.
3. Arteries have a thick elastic muscle layer, whereas the muscle layer for veins is much thinner.
Answer:
All human beings are 99.9 percent identical in their genetic makeup. Differences in the remaining 0.1 percent hold important clues about the causes of diseases.