Body Parts: Double-Jointedness, Hitchhiker's Thumb, and More

Can you stretch your thumb back to your arm? Is your pinkie straight or slightly bent? What determines the way your joints bend or don't bend? Read this book to find out! <br><br>Learn about the physical features you inherit in the What Traits Are in Your Genes? series--part of the Lightning Bolt BooksTM collection. With high-energy designs, exciting photos, and fun text, Lightning Bolt BooksTM bring nonfiction topics to life.