Among the organic macro-molecules, enzymes belong in the category of proteins. Proteins<span> are distinct from carbohydrates, </span>nucleic acids<span> and </span>lipids<span> in that a </span>protein<span> is made of </span>amino acids<span>.</span>
As far as I can tell, the answer would be D. Adaptation. The birds are evolving to adapt to their environment, and as such, their beaks are getting larger to crack larger seeds.
Which organism belongs to more than one trophic level
Water is H2O so that's Hydrogen and Oxygen.
