Osteoblast EM

This EM shows an area of bone formation. Osteoblast cells are depositing osteoid, which is then calcified through calcium hydroxyapatite deposition into bone. Note the presence of collagen fibers next to the osteoblasts. What type of collagen do osteoblasts synthesize? What organelle is particularly abundant in the cytoplasm of the osteoblast? Why would you expect this to be the case?