Q: The vertebrate endoskeleton is made of bone and what tough, flexible tissue?


Read this paragraph and choose the correct option from the provided answers:

The vertebrate endoskeleton is made of bone and cartilage. Cartilage is a tough, flexible tissue that contains a protein called collagen. Bone is a hard tissue consisting of a collagen framework that is filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. A bony endoskeleton allows an animal to grow larger and heavier than a cartilage endoskeleton would. Bone also provides more protection for soft tissues and internal organs.

 Choices:

- cuticle

- collagen

- synovial tissue

- cartilage


A:
cartilage