one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome

Which statement is true about the cell theory? a) it is well-supported by evidence. b) it is unchangeable and permanent.

What causes darkening of the skin as melanin production increases

Which best describes the scientific method? a. a path of clearly defined steps that must be followed in a particular order b. a possible answer to a scientific question based on knowledge or research c. the recipe for how to conduct an experiment that must be followed precisely d. the process of hypothesis and testing through which scientific inquiry occurs