NEET BIOLOGY

Detailed explanation-1: -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-2: -Chordates do not have an exoskeleton; they have an endoskeleton, which is an internal skeleton. The chordate skeleton includes structures called vertebrae in a subphylum of organisms called vertebrates, which includes humans, fish and amphibians.

Detailed explanation-3: -Chordates are also bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit metameric segmentation.

Detailed explanation-4: -They have well developed vertebral column forming the main axis of their internal skeleton, which may be of bones or cartilage.

Detailed explanation-5: -Of the approximately 50, 000 living chordates, 97% are vertebrates-animals whose skeletons include a backbone. Three features are present in all chordates. These include a stiffening rod, called a notochord that in many members (e.g., the vertebrates) is replaced during development by a bony, vertebral column.