What are melanosomes?

• A. Packets of color distributed to keratinocytes
• B. Immune cells in epidermis
• C. Organelles involved in collagen synthesis
• D. Enzymes that break down melanin

Answer: (A)

Melanosomes are pigment-containing organelles inside melanocytes that synthesize and store melanin, then transfer these pigment-filled vesicles to the surrounding keratinocytes. This transfer distributes color to the epidermis, hair, and eyes, and the melanin within keratinocytes helps shield DNA in the cell nuclei from UV damage. The other options describe different cell types or functions: immune cells in the epidermis are not pigment carriers, collagen synthesis is done by fibroblasts, and melanin-degrading enzymes are not what define melanosomes.