Genes Say: jeenz These aren't the blue pants that hang in your closet! These genes hang out all lined up on thread-like things called chromosomes (say: kro-moh-soamz). Genes are made up of segments of DNA and they determine physical traits, including the color of your eyes and whether your hair is straight or curly. You inherited your genes from your parents, which is why someone might say you have your mother's smile. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.