Bone matrix contains the protein ……………... while that of cartilage contains that protein…………

Explanation

To answer the question, we need to identify the proteins present in the matrices of bone and cartilage. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Identify the Matrix of Bone**: The first part of the question asks about the bone matrix. The matrix is the structural framework of the bone that provides strength and rigidity.

2. **Determine the Protein in Bone Matrix**: The protein that is predominantly found in the bone matrix is called **osteoprotein**. This protein contributes to the hardness and rigidity of the bone.

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