What Are Bones Made Of

About this printable What Are Bones Made Of science reading passage, NGSS-aligned (Grades 3-5)

This engaging 250-word reading passage introduces Grade 4 students to the structure and function of bones, aligned with NGSS standard 4-LS1-1 and Disciplinary Core Idea LS1.A. Students discover that bones are not dry and dead like they appear in pictures, but are actually living parts of the body with important jobs. The passage explains the hard outer layer that provides strength and protection, and the softer inside called bone marrow that produces blood cells. Students learn how bones grow as they grow and can even heal themselves when broken. The passage includes audio integration for accessibility, bold key vocabulary terms with immediate definitions, and relatable examples. Supplementary materials include a simplified differentiated version for struggling readers, Spanish translations of both passages, an 8-question multiple-choice quiz testing recall and comprehension, writing activities requiring application of concepts, and two graphic organizers (Structure and Function Table, Main Idea and Supporting Details Table) to help students organize their understanding. This comprehensive resource helps students build foundational understanding of bones as living, active structures essential for body support, protection, movement, and blood cell production.

Written by Workybooks TeamPublished by Workybooks

Sample passage and quiz from What Are Bones Made Of

When you see a picture of a skeleton, bones look white, hard, and dry. But the bones inside your body are very different. Bones are living parts of your body, just like your skin, heart, and muscles. They are alive and working every day to keep you healthy and strong.

Each bone has two main parts. The outside of a bone has a hard layer called compact bone. This layer is very strong and protects the bone. It gives your body shape and helps you stand, walk, and move. The compact bone is like a hard shell that keeps the bone safe.

Inside the bone is a softer part called bone marrow. Bone marrow is like a soft sponge. It has an important job—it makes blood cells that travel through your body. Blood cells carry oxygen to all your body parts and help you fight germs when you are sick. Without bone marrow, your body could not make new blood cells.

Because bones are alive, they can do amazing things. Bones grow as you grow taller and bigger. When you are a baby, your bones are small and soft. As you get older, your bones grow longer and harder. If you break a bone, special cells work together to heal the bone and make it strong again. This can take several weeks, but your living bones can fix themselves!

Interesting Fact: An adult human has 206 bones, but a baby is born with about 300 bones! As babies grow, some of their smaller bones join together to form bigger, stronger bones.