Two true breeding inbred lines of mice differ for growth and mature size. Line B6 is larger in size and is solid black for coat color, whereas line G13 is smaller in size and has solid gray coat color. A schematic representation for one homologous chromosome pair possessed by each line is shown below.
A scientist decides to cross these two mice lines and then to subsequently interbred individuals within each generation (F1 individuals are interbred to produce the F2 generation, F2 individuals are interbred to produce the F3 generation, etc.) for several generations.
Based on the homologous chromosome pairs in the image below, the choice most likely to represent an F1 individual is
, and the choice most likely to represent an F2 individual is