Answer:
Digestion is important for breaking down food into nutrients, which the body uses for energy, growth, and cell repair. Food and drink must be changed into smaller molecules of nutrients before the blood absorbs them and carries them to cells throughout the body. The body breaks down nutrients from food and drink into carbohydrates, protein, fats, and vitamins.
When a lineage splits into multiple line of descents, then, it leads to speciation. It is a process by which a single population evolves into different species. The process of speciation leads to the development of two or more species as the lineages are splitted. These two evolved species are genetically independent.
Hence, the blank can be filled with 'speciation'.
The term "lipid" does not specify a particular chemical structure. Whereas one can write a general formula for an amino acid, nucleic acid, or protein, lipids are much more chemically diverse. Compounds are categorized as lipids based on their greater solubility in organic solvents than in water.