Colorblindness is caused by a recessive gene on the X chromosome. Since men have only one X chromosome, if a man carries the colorblindness allele (gene form), he will have the trait. Women have two X ...

Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. David Kindness is a Certified Public Accountant (CPA) and an expert in the fields of ...