Question

Left: A frog with its organs highlighted. Right: A frog skeleton.
Examine the physical characteristics of the frog and determine if it is a vertebrate or an invertebrate. Be sure to justify your answer.

Answer 1

The frog is a vertebrate.

Justification:
- The right image shows a clear internal bony skeleton with a skull and a series of vertebrae (a backbone). The presence of a vertebral column is the defining feature of vertebrates.
- The left image shows complex, internal organs (heart, lungs, digestive organs) that are supported and protected by an internal (endoskeleton) framework—typical of vertebrate anatomy.
- Frogs are members of the class Amphibia, which are all vertebrates.

In contrast, invertebrates lack a backbone and typically have either no rigid internal skeleton or an external skeleton (exoskeleton). The frog’s backbone and internal skeleton make it a vertebrate.