In a particular diploid organism the Q gene has a functional

In a particular diploid organism, the Q gene has a functional allele (Q) and a non-functional (null) allele (q). You wish to determine whether Q is dominant to q, or whether it is incompletely dominant. Fill in the table with the control genotype(s) you should include in your analysis that will allow you to interpret the phenotypic results for Q/q heterozygotes.

Explain your reasoning.

Solution

Positive control is a reaction in which positive response is expected. In positive control, you should cross \'QQ\' with \'qq\'. If \'Q\' is dominant, then the entire progeny will have the phenotype of \'Q\'; if \'Q\' is incompletely dominant, then the entire progeny will have a different phenotype other than that of the parent.

Negative control is a reaction in which negative response is expected. In this, you should cross \'qq\' with \'Qq\'. The dominant phenotype \'Q\' will not appear at all if \'Q\' is incompletely dominant.

Gentotype

Positive Control

QQ

Experiment

Q/q

Negative Control

qq