Final answer:
Primarily, cells involved in the storage of calcium, like muscle cells and osteocytes, have a well-developed sarcoplasmic reticulum or a rich bone matrix respectively, to store and regulate calcium ions necessary for various cellular functions.
Step-by-step explanation:
Cells that are primarily responsible for the storage of calcium most likely possess a large amount of well-developed sarcoplasmic reticulum (SER) in the case of muscle cells, or a substantial bone matrix in the case of osteocytes.
In muscle cells, the sarcoplasmic reticulum serves as a storage site for calcium ions, which are crucial for triggering the coordinated contractions of the muscle cells.
Similarly, osteocytes within bones are networked together and are surrounded by bone matrix that contains massive amounts of calcium in the form of hydroxyapatite, calcium carbonate, and calcium phosphate. This allows for the regulation of blood calcium levels, with bones releasing calcium when levels drop too low.