1. What are valves (in a blood vessel) used for?
- To stop the blood from flowing
- To direct the flow of blood
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Other questions in this quiz
2. Which blood vessel has valves?
- The Titanic
3. What type of blood vessel carries blood away from the heart?
4. What do platelets do?
- Produce antigens and antibodies
- Help clot the blood
- Hold food
- Carries oxygen
5. Do red blood cells have a nucleus?
- Only the white ones
- Only some