Why does skin tanning in response to UV radiation differ significantly among individuals with varying levels of constitutive melanin?

💡 Explanation

The tanning response differs due to variations in melanosome transfer efficiency, which is genetically influenced. Melanosome transfer—the mechanism by which melanocytes transfer melanin to keratinocytes—varies; therefore, some individuals tan more readily than others, rather than due to differences in melanocyte numbers or melanin production capacity alone.

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