Question

The structure present in all adult vertebrates is:
A. Notochord
B. The dorsal tubular nerve cord
C. Pharyngeal gill slits
D. All of these

Answer 1

Hint: The vertebrae are characterized by the presence of notochord, endoskeleton, pharyngeal gill slits, dorsal tubular nerve cord.

Complete answer:Vertebrata includes all the animals that have the backbone (called spinal cord) that is generally surrounded by the cartilage or bone. The presence of the backbone is the characteristic feature of all the vertebrates.
Vertebrates include birds, fishes, amphibians, reptiles, and mammals.
1. The first option that is Notochord is referred to as the “cartilaginous skeletal rod that helps in supporting the body at all phases of development”
2. The second option- Dorsal tubular nerve cord is found in the modified form as the central nervous system and is found in the dorsal position to the notochord.
3. The third option- Pharyngeal gill slits are the opening in the pharynx that later develops into the gills in the case of the bony fishes but in the case of the terrestrial animals, it is modified into the jaw and inner ear.
4. Since all these features are the characteristic traits of the vertebrates therefore, the correct option is D. All of these.

Additional information: Characteristic features of Vertebrate are as follows:
1. Presence of the endoskeleton that is made up of cartilages and bones.
2. The brain is well protected by the skull that is the cranium.
3. Closed circulatory system.

Note:The basis of classification like endoskeleton, gill slits, cranium have distinguished the organisms and helped in deciding the habitat in which different organisms can live.