Because identical twins begin as a single fertilized egg that then separates, identical twins share percent of genetic makeup.
a. 100
b. 75
c. 50
d. 25

According to the article, what valid claim came from the national research council? there is no association between fluoride exposure and increased cancer risk in humans. there is a possible link between fluoride exposure and increased cancer risk in humans. there is a definite link between fluoride exposure and increased cancer risk in humans.