To determine the frequency of the [tex]\( rr \)[/tex] genotype in the plant population, follow these steps:
1. Determine the total number of individuals in the population:
- There are 20 individuals with the [tex]\(RR\)[/tex] genotype.
- There are 50 individuals with the [tex]\(Rr\)[/tex] genotype.
- There are 30 individuals with the [tex]\(rr\)[/tex] genotype.
Thus, we calculate the total number of individuals as:
[tex]\[
\text{Total number of individuals} = 20 + 50 + 30 = 100
\][/tex]
2. Calculate the frequency of the [tex]\( rr \)[/tex] genotype:
- The [tex]\( rr \)[/tex] genotype has 30 individuals.
- The frequency of a particular genotype is given by the number of individuals with that genotype divided by the total number of individuals in the population.
Thus, the frequency of the [tex]\( rr \)[/tex] genotype is:
[tex]\[
\text{Frequency of } rr = \frac{\text{Number of individuals with } rr}{\text{Total number of individuals}} = \frac{30}{100} = 0.3
\][/tex]
Therefore, the frequency of the [tex]\( rr \)[/tex] genotype is [tex]\( 0.3 \)[/tex].
The correct answer is:
D. 0.3
