Definition
A 'metamere' is a repeating structural unit along the body of some animals, also known as a segment or somite. Think of it like the repeating train cars of a long train 🚂. This segmentation is seen in annelids (segmented worms), arthropods (like insects), and chordates (including vertebrates). Each metamere may contain similar components like muscles, nerves, and blood vessels. Segmentation allows for more efficient movement and specialization of body regions. Understanding metameres is crucial in developmental biology. It helps explain how body plans are formed.