The variation in beak type enables the different individuals in a population to feed on different food sources.
The shape of the beak is key to determining the primary food source of the bird. Certain birds species have specialized beaks, but within populations of those species, there is a variation in beak shape.
This gives the population the ability to respond to changes in the environment and availability of different food sources.
For example, if because of a dry period there is a shortage of fruit, some individuals in the population have the beaks that enable them to feed on other things, survive and leave offspring.
Trophic levels go by,
Producer (The nuts)
Primary Consumer (Squirrels)
Secondary Consumer (Raccoons)
Tertiary Consumer (Bear)
So squirrels would be at a lower trophic level.
Hope his help :)
... whereby the body procedures glucose from amino acids and glycerone molecules
A monomer can be defined as the molecule that is capable of binding in long chains. The monomers bind together to form different polymers by the process of polymerization.
The monomer of carbohydrate is monosacchride. The monomer of proteins is amino acid, and that of lipids is glycerol and fatty acids. These three macromolecules are wrongly paired in the question.
The monomer of nucleic acids is nucleotide. This is correctly matched.
Hence, the correct answer is 'Option B - nucleic acids - nucleotides'.