It was concluded that hot rock from the mantle was rising up through the lithosphere and pushing the sea floorâand the continents on either sideâapart. This finding provided the mechanism to explain the purposeful movement of Earthâs plates and led to the development of the first theory of plate tectonics. Today Cooper is among a new generation of geologists who study what could be called âpostâ plate tectonics. Taking the field up a notch, she investigates similar processes on other planets and asks why Earth has plate tectonics in the first place.
Many mutations have no effect at all. These are called silent mutations. But the mutations we hear about most often are the ones that cause disease. Some well-known inherited genetic disorders include cystic fibrosis, sickle cell anemia, Tay-Sachs disease, phenylketonuria and color-blindness, among many others.All of these disorders are caused by the mutation of a single gene.Most inherited genetic diseases are recessive, which means that a person must inherit two copies of the mutated gene to inherit a disorder.any mutations have no effect at all. These are called silent mutations. But the mutations we hear about most often are the ones that cause disease. Some well-known inherited genetic disorders include cystic fibrosis, sickle cell anemia, Tay-Sachs disease, phenylketonuria and color-blindness, among many others.
If a person inherits from a parent a genetic mutation that causes a certain disease, then he or she will usually get the disease. Sickle cell anemia, cystic fibrosis, and early-onset familial Alzheimer's disease are examples of inherited genetic disorders. In other diseases, a genetic variant may occur. A single gene can have many variants. Sometimes, this difference in a gene can cause a disease directly. More often, a variant plays a role in increasing or decreasing a person's risk of developing a disease or condition.