NEET BIOLOGY

Detailed explanation-1: -The phylum Chordata contains all of the animals that have a rod-like structure used to give them support. In most cases this is the spine or backbone. Within Chordata there are five classes of animals: fish, amphibians, reptiles, birds, and mammals.

Detailed explanation-2: -Animals in the phylum Chordata share four key features: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

Detailed explanation-3: -The phylum chordata (animals with backbones) is divided into five common classes: fish, amphibians, reptiles, mammals and birds.

Detailed explanation-4: -Phylum Chordata belongs to the Kingdom Animalia and includes all the vertebrates, i.e., animals with a backbone, and several invertebrates, i.e., organisms without a backbone. They possess a bilaterally symmetrical body and are divided into three different sub-phyla.

Detailed explanation-5: -Like amphibians, reptiles are vertebrates (in the phylum Chordata) and most are ectothermal. Reptiles evolved from salamander-like creatures about 315 million years ago.