Biological Science 6th Edition by Scott Freeman,Kim Quillin,Lizabeth Allison,Michael Black,Greg Podgorski,Emily Taylor,Jeff Carmichael

Exercise 1

The genes for the traits that Mendel worked with are either located on different chromosomes or so far apart on the same chromosome that crossing over almost always occurs between them. How did this circumstance help Mendel recognize the principle of independent assortment?
A) Otherwise, his dihybrid crosses would not have produced a 9 : 3 : 3 : 1 ratio of F2 phenotypes.
B) The occurrence of individuals with unexpected phenotypes led him to the discovery of recombination.
C) It led him to the realization that the behavior of chromosomes during meiosis explained his results.
D) It meant that the alleles involved were either dominant or recessive, which gave 3 : 1 ratios in the F1 generation.