When it comes to the animal kingdom, there are two main categories: vertebrates and invertebrates. Vertebrates, like humans, have a backbone and spinal column that provides support and protection for their bodies. In contrast, invertebrates do not have a backbone or spinal column, which means they lack a key structural feature that vertebrates possess.

One of the main things that an invertebrate lacks is a backbone. This means that invertebrates have a different body structure than vertebrates, with no internal skeleton to support their bodies. Instead, invertebrates rely on other structures, such as exoskeletons or hydrostatic skeletons, to provide support and protection.

Another thing that invertebrates lack is a spinal cord. The spinal cord is a crucial part of the vertebrate nervous system, transmitting signals between the brain and the rest of the body. Invertebrates have a different nervous system structure, with nerve cords and ganglia that serve a similar function to the vertebrate spinal cord.

In addition to lacking a backbone and spinal cord, invertebrates also lack certain other features that are common in vertebrates. For example, invertebrates do not have lungs or gills for breathing. Instead, many invertebrates respire through their skin or rely on specialized structures like tracheae or book lungs.

Overall, what an invertebrate lacks compared to a vertebrate is a backbone, spinal cord, and certain other specialized structures. Despite these differences, invertebrates are a diverse and fascinating group of animals that have adapted to a wide range of environments and lifestyles.

For more information on invertebrates and the differences between vertebrates and invertebrates, you can visit websites like National Geographic or Encyclopedia Britannica.

Sign Up