Final answer:
To tell the difference between an invertebrate and a vertebrate, you can examine their skeletal structure, observe their locomotion, and study their reproductive methods.
Step-by-step explanation:
To tell the difference between an invertebrate and a vertebrate, you can examine their skeletal structure. Vertebrates have a backbone made of bone or cartilage, while invertebrates lack a backbone. You can also observe their locomotion - vertebrates typically have more complex and specialized modes of movement compared to invertebrates. Lastly, you can study their reproductive methods. Most invertebrates reproduce sexually and go through larval stages, while vertebrates have different reproductive strategies.