Final answer:
The digestive system breaks down polymers of macromolecules in food into monomers. Monomers such as amino acids, monosaccharides, fatty acids, and nucleotides are then used by cells to synthesize their own polymers.
Therefore, option a is correct.
Step-by-step explanation:
The simple idea behind your digestive system is to break down the polymers of macromolecules in your food into monomers that your cells use to build their own polymers. Therefore, the correct answer to the question is (a) Monomers.
Courses in biology often emphasize the enzymes and processes involved in breaking down food into absorbable units. During digestion, complex macromolecules such as proteins, carbohydrates, lipids, and nucleic acids are broken down by the process of hydrolysis, a reaction which involves the addition of water to split the bonds holding the monomers together.
The monomers, such as amino acids (from proteins), monosaccharides (from carbohydrates), fatty acids (from lipids), and nucleotides (from nucleic acids), are then absorbed by the body and reassembled into necessary polymers through dehydration synthesis, also known as condensation reactions, where water is removed to form new covalent bonds.