What is a mosaic in genetics?
Q: What is a mosaic in genetics?
A: A mosaic in genetics refers to the presence of two different genotypes in an individual which developed from a single fertilized egg.
Q: How does an individual develop multiple genotypes?
A: An individual develops multiple genotypes due to mosaicism, which may result from crossing-over during mitosis, a gene mutation or a chromosomal mutation during development, or X-inactivation in female mammals.
Q: What is X-inactivation in female mammals?
A: X-inactivation is a phenomenon where one of the two X chromosomes in female mammals is randomly switched off in cells, resulting in the expression of only one of the X chromosomes.
Q: Who discovered the phenomenon of mosaicism?
A: The phenomenon of mosaicism was discovered by Curt Stern, who demonstrated in 1936 that recombination, which is normal in meiosis, can also take place in mitosis, resulting in somatic mosaics.
Q: What are somatic mosaics?
A: Somatic mosaics are organisms that contain two or more genetically distinct types of tissue.
Q: What are the causes of mosaicism?
A: Mosaicism can be caused by crossing-over during mitosis, a gene mutation or a chromosomal mutation during development, or X-inactivation in female mammals.
Q: What is the significance of mosaicism in genetics?
A: Mosaicism is significant in genetics because it can result in individuals with a wide range of phenotypes, which can have important implications in fields such as medicine and evolutionary biology.
