DENDROLOGY

Detailed explanation-1: -invertebrate, any animal that lacks a vertebral column, or backbone, in contrast to the cartilaginous or bony vertebrates. More than 90 percent of all living animal species are invertebrates.

Detailed explanation-2: -As invertebrates lack an internal skeletal structure, they sometimes have an external skeleton that protects their soft bodies called an “exoskeleton.” In general, invertebrate success often comes from their ability to reproduce extremely quickly, unlike many vertebrates who take years to become fully grown.