Fact 1: Cartilage is a tough tissue that contains a protein called collagen.

Fact 2: Many collagen fibrils come together and form a collagen and forma collagen fiber.

Given the two facts above, answer the question "Cartilage is a tough tissue made up of:" with the following options: 
- a cuticle
 - bones
 - Joules
 - neurons
 - the skin
 - loose soil
 - fibrils
 - muscle


 

       fibrils  