Question

unlike cartilage, bone
○ has an outer covering.
○ undergoes remodeling throughout life.
○ has a matrix that contains collagen.
○ has cells within lacunae.
○ is a connective tissue.

Explanation:

1. Analyze each option:

• Option "has an outer covering": Bone has a periosteum (outer covering), while cartilage (except for some with perichondrium in growth phases) generally lacks a distinct outer covering like bone's periosteum.
• Option "undergoes remodeling throughout life": Both bone and cartilage can undergo changes (cartilage can grow, repair to some extent), so this is not a unique difference.
• Option "has a matrix that contains collagen": Both bone and cartilage matrices contain collagen.
• Option "has cells within lacunae": Both bone (osteocytes) and cartilage (chondrocytes) have cells within lacunae.
• Option "is a connective tissue": Both bone and cartilage are connective tissues.

1. Conclusion: The key difference here is that bone has a distinct outer covering (periosteum) which cartilage does not have in the same way.

Answer:

A. has an outer covering.