NEET BIOLOGY

Detailed explanation-1: -Only five percent of all known living animal species are vertebrates or animals with backbones (Fig. 3.3). The vast majority of animal species (95 percent) are invertebrates. Among all animal species, one particular group easily claims the highest number of species: the insects.

Detailed explanation-2: -Invertebrates make up over 95 percent of the Earth’s animal species.

Detailed explanation-3: -To group all invertebrates together is an immodest proposal, since the definition of “invertebrate” is any animal without a spinal column-no less than 97 percent of all animal species on Earth.

Detailed explanation-4: -This is by far the largest group in the animal kingdom: 97 percent of all animals are invertebrates. So far, 1.25 million species have been described, most of which are insects, and there are millions more to be discovered.