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.
Not sure what the choices are but a biotic factor is anything living.
Answer:
Solar energy is the most efficient compared to fossil fuels. The sun is a free and renewable source of energy. Solar energy also has less environmental impact.
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