What's a Gene? - Eric Green
Channel: National Human Genome Research Institute
Date: 2013-06-11

In 1909, Danish botanist Wilhelm Johannsen coined the word "gene" to describe Mendelian units of heredity. As researchers learned more, they began to define genes as a segment of a DNA molecule that contains information for making a protein or, sometimes, an RNA molecule. The term continues to evolve as scientists learn about the complexities of molecular interactions. Listen to some well-known scientists respond to the question, "What's a gene?"
More: http://www.genome.gov/27554026