Body Parts: Double-Jointedness, Hitchhiker’s Thumb, and More
Body Parts: Double-Jointedness, Hitchhiker’s Thumb, and More
From the Series Lightning Bolt Books ® — What Traits Are in Your Genes?
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 about how your genes… Read More →