Which is the best physical description of a gene

Answer: Gene is defined as a segment of DNA (deoxyribonucleic acid) that codes for a particular protein and the protein thus formed corresponds to a specific trait (like eye color) of the organism.

Genes are passed from parents to their offsprings and in this way specific traits are inherited by offsprings from their parents.

Genes are located on the chromosomes (thread like structures composed of DNA).

A gene consists of all of the DNA on a chromosome.