What elements differentiate the amino acids of a protein from the sugars of a carbohydrate ?

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg 

i think the answer is a.keratin is the pigment responsible for skin color.