A species of birds from South America have feathers that are either blue, black, or both blue and black. There are only two alleles for the gene that codes for feather's color, A and U. Allele A controls black color, and the allele U controls blue color. The birds with blue and black feathers fully express the alleles A and U. Most likely, A and U are alleles. Dominant
Recessive
Codominant
Incomplete dominant

need points

Explanation:

:)

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.