Tag: classification of organisms

• Vertebrates are animals that have a backbone or spinal column, also called vertebrae.
• The five most well-known classes of vertebrates are mammals, birds, fish, reptiles, amphibians. They belong to the phylum Chordata.
  

The vertebral column, also known as the backbone or spine, is a bony skeletal structure found in vertebrates. It is formed from individual bones called vertebrae, which houses the spinal canal, a cavity that encloses and protects the spinal cord. Therefore, (d) is the correct answer. 

All chordates are characterised by three primary chordate features the presence of a notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. The notochord, later on, gives rise to a bony vertebral column, which surrounds and protects the spinal cord. So, the correct answer is option B.

All vertebrates have a living endoskeleton. The characteristic of vertebrates without exception is the presence of a brain. The brain is set inside a bony box called as the cranium. Cranium is made up of eight bones. It protects the human brain from mechanical injury.
Therefore, the correct answer is option B.

• The heart of vertebrates is ventrally placed.
• The body of vertebrates consists of serially arranged vertebrae which comprises of a major part of their axial exoskeleton, the vertebral column or the backbone.
• The coelom of vertebrates is large and well developed and it is of enterocoelous type.