Question

Assuming a typical monohybrid cross in which one allele is completely dominant to the other,

what ratio is expected if the F1s are crossed?
A) 2:1
B) 1:1
C) 3:2
D) 3:1
E) 4:3

Answer 1

The expected ratio when crossing the F1s in a monohybrid cross with one completely dominant allele is 3:1.

Step-by-step explanation:

In a typical monohybrid cross where one allele is completely dominant to the other, the expected ratio when the F1s (first filial generation) are crossed is 3:1. This ratio is obtained by using the Punnett square method to analyze the possible genotypes and phenotypes of the offspring. For example, if you cross two F1 individuals with genotypes Aa, you would expect approximately 75% of the offspring to have the dominant phenotype and 25% to have the recessive phenotype.