Which of the Following Crosses Would Produce a 3:1 Ratio

Question

Which of the following crosses would produce a 3:1 ratio of phenotypes in the next generation?
A)AA × AA
B)AA × aa
C)Aa × Aa
D)Aa × aa
E)aa × aa

Accepted Answer

A 3:1 ratio of phenotypes is indicative of a monohybrid cross, where only one trait is being studied. The cross Aa x Aa is a classic monohybrid cross that will produce a 3:1 ratio of dominant and recessive phenotypes in the next generation. The other crosses may produce different phenotypic ratios.