To determine the value of [tex]\( q \)[/tex] for a trait with two alleles [tex]\( p \)[/tex] and [tex]\( q \)[/tex], where [tex]\( p = 0.22 \)[/tex], we need to use the principle that the sum of the probabilities of both alleles must equal 1. This is based on the basic concept of allele frequencies in genetics, where:
[tex]\[
p + q = 1
\][/tex]
Given that [tex]\( p = 0.22 \)[/tex], we can find [tex]\( q \)[/tex] by rearranging the equation:
[tex]\[
q = 1 - p
\][/tex]
Substitute the given value of [tex]\( p \)[/tex]:
[tex]\[
q = 1 - 0.22
\][/tex]
Thus, we have:
[tex]\[
q = 0.78
\][/tex]
Therefore, the correct answer is:
A. 0.78
