Identical twins have exactly the same DNA, but they are not exactly alike. Each twin has his or her
own personality, talents, likes, and dislikes. There are even diseases that appear in one twin but not
the other, including arthritis, diabetes, autism, schizophrenia, cancer, and many others. The
differences between identical twins don't come from DNA-they all come from external factors.
Scientists often study twins to understand how genes and the environment work together to affect
traits. They compare traits in identical twins, who have identical DNA, and fraternal twins, who
share half their DNA, just like any siblings. If a characteristic appears more frequently in identical
twin pairs than in fraternal twin pairs, then it has an inherited component.
#1 What valuable information could a scientist gain from studying identical twins vs fraternal
twins.
A)If a disease has a greater chance of being inherited.
B)If fraternal twins do not get cancer.
C)The DNA of identical twins has a different structure
D)External environmnetal factors do not influence gene expression in identical twins.