Use the Punnett Square below to answer the question.
YY or Yy = yellow flowers
yy = white flowers
GG or Gg = green seeds
gg = black seeds
\begin{tabular}{|l|l|l|l|l|}
\hline & YG & Yg & yG & yg \\
\hline YG & YYGG & YYGg & YyGG & YyGg \\
\hline Yg & YYGg & YYgg & YyGg & Yygg \\
\hline yG & YyGG & YyGg & yyGG & yyGg \\
\hline yg & YyGg & Yygg & yyGg & yygg \\
\hline
\end{tabular}
What percent of offspring have the YYGG genotype?
A. $25 \%$
B. $6.3 \%$
C. $18.7 \%
Answer (1)
Count the number of YYGG genotypes in the Punnett square: 1.
Determine the total number of possible genotypes: 16.
Divide the number of YYGG genotypes by the total number of genotypes: 16 1 = 0.0625 .
Multiply by 100 to express as a percentage: 0.0625 × 100 = 6.25% .
Explanation
Understand the problem We are given a Punnett square and asked to find the percentage of offspring with the YYGG genotype. The Punnett square shows the possible genotypes resulting from a cross.
Count the number of YYGG genotypes First, let's count how many offspring have the YYGG genotype in the Punnett square. We can see that there is only one square with the YYGG genotype.
Determine the total number of possible genotypes The Punnett square is a 4x4 grid, which means there are a total of 16 possible genotypes.
Calculate the percentage To find the percentage of offspring with the YYGG genotype, we divide the number of YYGG genotypes by the total number of possible genotypes and multiply by 100: 16 1 = 0.0625 0.0625 × 100 = 6.25 So, 6.25% of the offspring have the YYGG genotype.
State the final answer Therefore, the percentage of offspring with the YYGG genotype is 6.25% .
Examples
Understanding genotype percentages is crucial in agriculture. For example, a farmer might want to know the likelihood of producing plants with specific traits, like disease resistance or high yield. By using Punnett squares and calculating these percentages, they can make informed decisions about which plants to crossbreed to achieve the desired characteristics in their crops. This helps optimize their harvests and improve the overall quality of their produce.
