Question

question 7
which of these describes the structure of a nucleic acid?
a hydrophilic head containing a glycerol and two hydrophobic tails
several fatty acids linked together
a chain of monomers composed of a sugar, a phosphate group, and a nitrogenous base
a long chain of monosaccharides

Explanation:

Nucleic acids like DNA and RNA are polymers. Their monomers are nucleotides, which consist of a sugar (ribose in RNA or deoxy - ribose in DNA), a phosphate group, and a nitrogenous base. The other options describe structures of lipids (hydrophilic head with glycerol and hydrophobic tails, fatty acids linked together) and carbohydrates (long chain of monosaccharides).

Answer:

a chain of monomers composed of a sugar, a phosphate group, and a nitrogenous base