Question

Give reasons for the following.
1. Ventricles have thicker walls than auricles.
2. Openings of auricles into ventricles are
guarded by valves.
3. Arteries have thick walls.
4. Valves are present in veins but not in arteries.
5. Persons of blood group O are universal
donors.​

Answer 1

Explanation:

Because ventricles have to pump blood up-to a large distance so ventricles have a thick wall