Which of the following repeating units make up a protein?
a. fatty acids
b. peptide acids
c. carboxylic acids
d. amino acids

9. wind power creates pollution. water air soil noise

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Many farmers prefer cattle without horns because it is safer for their herds. the allele for no horns (n) is dominant to the allele for the presence of horns (n). a farmer mates a male with horns to a heterozygous female without horns. what is the chance that the offspring will have horns?