So by looking at the seismic waves from earthquakes the scientist learned about the crust and the mantle but they also learned about the outer and inner core. To do this you have to look at a different kind of waves, the S (secondary waves) waves that also get released by an earthquake.
Answer:
The two strands are held together by hydrogen bonds between the bases, with adenine forming a base pair with thymine, and cytosine forming a base pair with guanine.
Explanation: hydrogen bonds
By looking at a gene set up or a punnet square,a gene that's dominant would be represented by a capital letter and recessive traits are represented by lowercase letters for example brown eyes are considered a dominant trait which can be represented as BB for homozygous, and Bb for heterozygous. Since blue eyes are recessive they would be bb.