Which statement about melanosomes is correct?

• A. They generate energy for the cell.
• B. They store calcium.
• C. They are responsible for cell division.
• D. They produce pigment inside cells.

Answer: (D)

Melanosomes are pigment-containing organelles within pigment-producing cells called melanocytes. They host the enzymatic steps that synthesize melanin from tyrosine, with enzymes like tyrosinase driving the reaction. The pigment is then stored inside the melanosome and can be transferred to neighboring keratinocytes, contributing to skin and hair color and providing some protection from UV radiation. This role is distinct from energy production, which occurs in mitochondria; calcium storage, primarily handled by the endoplasmic reticulum and mitochondria; and cell division, which relies on the nucleus and cytoskeletal machinery. So the defining function of melanosomes is producing pigment inside cells.