Ethnic differences in skin color are primarily caused by differences in the
quantity of melanin produced
quantity of hemoglobin in the blood
UV radiation exposure
number of keratinocytes
number of melanocytes
The Correct Answer is A
A. quantity of melanin produced: Ethnic variations in skin color are due to differences in the amount and type of melanin synthesized and distributed by melanocytes. While all humans have roughly the same number of melanocytes, the activity level of these cells determines pigment intensity.
B. quantity of hemoglobin in the blood: Hemoglobin contributes to skin tone by giving a reddish or pinkish hue, especially in lighter skin. However, it does not account for the baseline differences in ethnic skin color.
C. UV radiation exposure: Sun exposure can increase melanin production temporarily, leading to tanning. However, long-term ethnic differences are genetically determined rather than solely influenced by environmental UV exposure.
D. number of keratinocytes: Keratinocytes are the primary cells of the epidermis and act as recipients of melanin granules from melanocytes. Their number does not vary significantly among ethnic groups and does not explain differences in skin color.
E. number of melanocytes: The number of melanocytes is relatively consistent across all ethnicities. It is the rate of melanin synthesis and the type of melanin produced that create the observed differences in skin pigmentation.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is B
Explanation
A. reticular layer:The reticular layer is the deeper part of the dermis, composed mainly of dense irregular connective tissue. It provides strength, elasticity, and houses structures such as glands, nerves, and blood vessels, making it part of the skin.
B. hypodermis:The hypodermis, also known as the subcutaneous layer, lies beneath the dermis and is made up of adipose and connective tissue. It anchors the skin to underlying structures but is not technically considered part of the skin itself.
C. dermis:The dermis is one of the two main layers of the skin, lying beneath the epidermis. It contains connective tissue, blood vessels, and sensory receptors that support and nourish the epidermis.
D. epidermis:The epidermis is the outermost layer of the skin made of keratinized stratified squamous epithelium. It provides a protective barrier against environmental damage, pathogens, and water loss.
Correct Answer is B
Explanation
False:Supporting cells in nervous tissue that can divide are glial cells, not neurons. Glial cells maintain, protect, and support neuronal function, and they retain the ability to reproduce throughout life. Neurons are specialized cells responsible for transmitting electrical impulses, and they have a very limited ability to undergo cell division once mature. Damage to neurons usually results in permanent loss of function.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.