Answer:
The periosteum is one source of precursor cells which develop into chondroblasts and osteoblasts that are essential to the healing of bone. Other sources of precursor cells are the bone marrow (when present), endosteum, small blood vessels, and fibroblasts.
The answer for this question is false.
This process requires large volumes of water to pass through absorption surfaces to get enough oxygen into their bodies using their mouths and gills. These body parts work like a pump to keep water moving over the gas absorption surfaces of the gills.