The primary purpose of the pulmonary system is to
a. prevent waste products from entering the heart
b. provide a location for the exchange of gases.
c. increase blood flow to the heart
d. increase the amount of carbon dioxide in the blood

Use the drop down menus to match each example to the fossil topic discussed then to show how the fossil record gives evidence of evolution

How many major plates cover the earth

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.