Unit 2 Lesson 4

Melva said, "I think all animals need blood vessels to move blood from one part of the body to another."

Zach said, "I think some animals need blood vessels to move blood from one part of the body to another."

Dennis said," I think no animals need blood vessels to move blood from one part of the body to another."

Answer and Explain on pg 115

1. Sit QUIETLY for 1 minute

2. Feel your pulse by placing the middle and index fingers of one hand on the artery in your neck or an artery in your wrist.

3. While sitting quietly, count the number of heartbeats you feel in 30 seconds. Multiply this number by two to calculate your pulse.

4. Record your data. 

5. Jog in place for 1 minute.

6. Immediately repeat steps 3 and 4

All animals must take in oxygen and eliminate carbon dioxide to survive. Oxygen must enter they body so the cells and tissues are able to use it for life processes. Some animals have respiratory systems and breathe like humans do. However, other animals perform gas exchange in different ways. Different Animals have different circulatory systems. The type of circulatory systems used often determines how quickly blood moves through the animal.