What is a gene?

Question

What is a gene?

Answer 1

A segment of DNA that codes for a soluble product, has an effect on phenotype, and occupies a specific loci on a chromosome.

Please note that not all genes code for protein. Sometimes RNA is the intended final product.

Answer 2

A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genes undergo mutation when their DNA sequence changes.

http://www.answers.com/topic/gene

Answer 3

It's a functional unit of DNA, typically encoding a protein, sometimes encoding an RNA that is function without being translated.