Eye color is also determined by genes. Brown eyes are dominant, and blue eyes are recessive. What must be true for two brown-eyed parents to produce a blue-eyed child?
A) One person passes on the blue-eye allele.
B) They each pass on the blue-eye allele.
C) One person's parents are blue-eyed.
D) One person's grandparents are blue-eyed.

answer:

C) One person's parents are blue-eyed.

Explanation:

You need a working HERC2 and a working OCA2 to have brown eyes. Because the two genes depend on each other, it is possible for someone to actually be a carrier of a dominant trait like brown eyes. And if two blue eyed parents are carriers, then they can have a brown eyed child.

I think that it's D because grandparents can pass down genes.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation:

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products