| Gene | Chromosomes |
| They are located on the chromosomes. | Chromosomes are the packed structure of a DNA with proteins. |
| Genes are composed of either DNA or RNA | Chromosomes composed of DNA, RNA and histones. |
| According to Human genome project, there are 30,000 genes in the human cell. | In Human cell there are 23 pair of chromosomes. In Gametic cell there are 23 chromosomes. |
| Gene mutation takes place at smaller scale. | Chromosome mutation takes place at larger scale. In evolution it takes time. |
| Genetic mutation is not lethal. In fact is desirable at lower level of life. | Chromosome mutation is generally lethal. |
| Gene is not visible under microscope. | Chromosome is visible under microscope. |