This book is part of a book series called Healthy Habits .

This book has been graded for interest at 10-13 years.

There are 64 pages in this book. This book was published 2010 by Rosen Central .

STEPHANIE WATSON is an independent scholar who has written and contributed to numerous works, including World of Genetics and Science and Its Times . She is the author of The Urinary System , and coauthor of The Endocrine System , both in Greenwood's Human Body Systems series.