In mice, coat color is determined by 2 epistatically interacting genes. Mice with genotype aa for the first gene are always albino; otherwise, they can produce melanin. If they produce melanin (have at least 1 A allele), then their coat color is determined by a second gene. In particular, if their genotype at this second locus is bb, then they are black. Otherwise, they are agouti (brown). For example, a mouse with genotype Aabb is black, but one with genotype aabb is albino; genotype AaBb produces an agouti mouse. What is the phenotypic ratio of the following cross: aaBb x Aabb?

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.