Is there only one gene that affects human hair color? what besides gene influences traits?

What happens when a scientific theory is shown to be an accurate description of a phenomenon?

Which of the following is the best definition of a eukaryota? a. a one-celled organism that does not have a membrane-bound nucleus b. a one-celled organism that does not have a cell wall c. an organism whose cells each contain a membrane-bound nucleus d. an organism whose cells each have a cell wall

For each of the formulas, classify the formula as either an empirical formula, a molecular formula, or both. nahco3 empirical molecular both