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: -Invertebrates are animals without a backbone or bony skeleton. They range in size from microscopic mites and almost invisible flies to giant squid with soccer-ball-size eyes. This is by far the largest group in the animal kingdom: 97 percent of all animals are invertebrates.

Detailed explanation-3: -5 % of animal species are vertebrates. Flatworms, arthropods, sponges, insects are a few examples of Invertebrates. Mammals, fish, reptiles, amphibians, and birds are examples of Vertebrates.