Answer:
D. A segment of DNA molecule
Explanation:
Gene is a segment of a DNA molecule that holds instruction needed for the synthesis of useful products (protein). Ideally, DNA is the storage material of genetic information in a cell. The DNA harbors the GENE, which itself is being expressed in order to use the information contained in it to produce useful products responsible for the phenotype of an organism.
A gene contains sequences made up of nucleotide bases that determines the sequence of amino acids to be produced, and ultimately the type of protein.
