Final answer:
The subject of this question is Biology and the grade level is High School.
Step-by-step explanation:
The subject of this question is Biology and the grade level is High School.
The description given in the question is referring to calcified cartilage in long bones.
This area consists of a few cells thick and is mostly made up of dead chondrocytes because the extracellular matrix around them has calcified, preventing diffusion of nutrients into the matrix.