1. For many generations, the following genotypic frequencies were observed in a large population of dinosaurs: 4 percent AA, 32 percent Aa, and 64 percent aa. The climate changed abruptly and resulted in the death of all homozygous recessive dinosaurs (s = 1). In the next generation, the recessive homozygotes died shortly after birth. What percentage of these newborn dinosaurs died?
2. Two new mutant lines of a flowering plant have been obtained; one breeds true for blue flower color and the other breeds true for red flower color (wild-type flower color is purple). Consider the following crosses:
1. blue × purple ??F1 all purple ??F2 75% purple; 25% blue
2. red × purple ??F1 all purple ??F2 75% purple; 25% red
3. red × blue ???F1 all purple
If the purple flower color results from the mixture of red and blue pigments, and all the
intermediate products in the pigment pathways are colorless, what phenotypic ratios do you expect in the F2 of cross 3?