Search results
Results from the WOW.Com Content Network
Ionizing radiation can cause biological effects which are passed on to offspring through the epigenome.The effects of radiation on cells has been found to be dependent on the dosage of the radiation, the location of the cell in regards to tissue, and whether the cell is a somatic or germ line cell.
Excessive solar radiation causes direct and indirect DNA damage to the skin and the body naturally combats and seeks to repair the damage and protect the skin by creating and releasing further melanin into the skin's cells. With the production of the melanin, the skin color darkens, but can also cause sunburn.
The first modern humans had darker skin as the indigenous people of Africa today. Following migration and settlement in Asia and Europe, the selective pressure dark UV-radiation protecting skin decreased where radiation from the sun was less intense. This resulted in the current range of human skin color.
Melanocytes are melanin-producing neural crest-derived [3] cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), [4] the inner ear, [5] vaginal epithelium, [6] meninges, [7] bones, [8] and heart found in many mammals and birds. [9] Melanin is a dark pigment primarily responsible ...
Types of mutations that can be introduced by random, site-directed, combinatorial, or insertional mutagenesis. In molecular biology, mutagenesis is an important laboratory technique whereby DNA mutations are deliberately engineered to produce libraries of mutant genes, proteins, strains of bacteria, or other genetically modified organisms.
The Fitzpatrick scale has been criticized for its Eurocentric bias and insufficient representation of global skin color diversity. [9] The scale originally was developed for classifying "white skin" in response to solar radiation, [2] and initially included only four categories focused on white skin, with "brown" and "black" skin types (V and VI) added as an afterthought.
Melanism is the congenital excess of melanin in an organism resulting in dark pigment. Pseudomelanism, also called abundism, is another variant of pigmentation, identifiable by dark spots or enlarged stripes, which cover a large part of the body of the animal, making it appear melanistic. [2]
Overexposure to ultraviolet radiation is known to cause skin cancer, [19] make skin age and wrinkle faster, [20] mutate DNA, [21] and impair the immune system. [22] Frequent tanning bed use triples the risk of developing melanoma, the deadliest form of skin cancer, according to a 2010 study.