The answers would be:
1. Cell wall
2. Vertebrates contain a backbone, while invertebrates do not.
The cell wall is found in a plant cell. This is one of the features of a plant cell that makes it different from animal cells. Other features in the plant cell that is not in the animal cell are presence of chloroplasts and a large vacuole.
2. The word vertebrate comes from vertebrae, which are the bones that make up our spine or in other words, backbone.
The word invertebrate can be broken down to give you a more obvious explanation: In - means without.