Question

Without melanocytes, skin would a. be too thin. b. lack nerves. c. not tan. d. not be waterproof.

Short answer

c. not tan.

Step-by-step solution

Understanding melanocytes

Melanocytes are cells found in the basal layer of the skin, and they are responsible for producing melanin. Melanin is the pigment responsible for the color of our skin, hair, and eyes. The primary function of melanocytes is to protect the skin from the harmful effects of ultraviolet (UV) radiation by producing melanin.

Eliminate options not related to melanocytes function

Based on the understanding of melanocytes function, let's eliminate the options that are not related to them: a. Skin thickness: Skin thickness is determined by the different layers present in the skin and is not related to melanocytes' function. So, this option can be eliminated. b. Nerves in skin: The function of melanocytes is unrelated to the nerves found in the skin, so this option can also be eliminated. d. Waterproof skin: Skin waterproofing is primarily due to the presence of lipids (fats) in the outermost layer of the skin called the stratum corneum. Melanocytes are not responsible for these lipids, so this option can be eliminated.

Select the correct option

By eliminating the unrelated options, we are left with the correct option: c. Not tan. The tanning of the skin is caused by an increase in the production of melanin by melanocytes due to exposure to UV radiation. Without melanocytes, the skin would not be able to produce melanin and therefore would not tan when exposed to sunlight.

Key concepts

Melanin

Melanin is a natural pigment found in our bodies, originating from cells called melanocytes. It plays a crucial role in the coloration of our skin, hair, and eyes. The primary purpose of melanin is to provide pigmentation, giving color to these parts of our bodies.

Moreover, melanin acts as a protective shield against UV radiation. When our skin is exposed to the sun, melanocytes produce more melanin, effectively absorbing and dissipating the UV rays. This process helps prevent damage to our skin cells.

• Melanin is produced by melanocytes.
• Determines the color of skin, hair, and eyes.
• Offers protection against harmful UV rays.

Skin Pigmentation

Skin pigmentation refers to the color of our skin, which is primarily determined by the presence of melanin. The amount and type of melanin vary among individuals, resulting in different skin tones.

Each person has similar numbers of melanocytes, but the amount of melanin these cells produce can vary greatly. Factors such as genetics, hormonal changes, and sun exposure can affect melanin production, leading to changes in skin pigmentation.

• Affected by genetics and environmental factors.
• Increased exposure to sun can darken skin tone temporarily, known as tanning.
• Makes each individual's skin color unique.

UV Radiation Protection

Our skin is constantly exposed to ultraviolet (UV) rays from the sun, which can be harmful if absorbed in large amounts. Melanocytes provide a protective function by producing melanin, which acts as a natural sunscreen.

When UV rays penetrate the skin, they can cause damage to the DNA of skin cells, potentially leading to skin cancer. Melanin absorbs and scatters these rays, minimizing the risk of harm. This protective response becomes more robust with repeated exposure, which is why we tan.

• Melanin absorbs and reduces harmful effects of UV rays.
• Protects skin cells from DNA damage.
• Contributes to tanning as a natural defense mechanism.