NEETBotanyAnimal Kingdom
Which of the following statements correctly distinguishes members of Class Cyclostomata from members of Class Chondrichthyes?
Options
- ACyclostomes have a bony cranium and vertebral column, whereas Chondrichthyes have a cartilaginous skeleton.
- BCyclostomes possess paired fins for swimming, whereas Chondrichthyes lack paired appendages.
- CCyclostomes have an open circulatory system, whereas Chondrichthyes have a closed circulatory system.
- DCyclostomes lack scales on their body, whereas Chondrichthyes possess tough skin with minute placoid scales.
Correct answer
D. Cyclostomes lack scales on their body, whereas Chondrichthyes possess tough skin with minute placoid scales.
Step-by-step solution
Members of Class Cyclostomata (Division Agnatha) are jawless vertebrates whose bodies are devoid of scales and paired fins. In contrast, members of Class Chondrichthyes (Division Gnathostomata) have powerful jaws, paired fins, and tough skin containing minute placoid scales. The other options are incorrect because both Cyclostomata and Chondrichthyes possess a cartilaginous endoskeleton (cranium and vertebral column) and both have a closed type of circulatory system. Furthermore, it is Chondrichthyes that possess p