Final answer:
Smooth ER is mainly present in lipid-forming cells like those in the ovaries and testes, which produce steroid hormones, and has functions in lipid synthesis, detoxification, and calcium storage.
Step-by-step explanation:
The smooth endoplasmic reticulum (SER) is vital for several cellular functions which include the synthesis of carbohydrates, lipids, and steroid hormones. Particularly, it is abundant in cells specialising in lipid synthesis like those in the female ovaries and male testes, which produce large quantities of steroid hormones. In addition, the smooth ER has roles in detoxification, storage of calcium ions, and the metabolism of some carbohydrates. For instance, Leydig cells in the testes have abundant smooth ER to facilitate the production of testosterone. It's also integral in muscle cells, such as the sarcoplasmic reticulum, for storing calcium ions vital for muscle contractions.