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 ys & YyGg & Yygg & yyGG & yygg \\
\hline
\end{tabular}
What percent of offspring have white flowers and green seeds?
A. $25 \%$
B. $6.3 \%$
C. $18.7 \%
Answer (2)
Identified offspring with white flowers (yy) and green seeds (GG or Gg) from the Punnett square.
Counted 3 offspring with the desired traits.
Calculated the fraction of offspring with white flowers and green seeds: 16 3 .
Converted the fraction to a percentage: 18.7% .
Explanation
Analyze the problem Let's analyze the problem. We are given a Punnett square that shows the genotypes of offspring for two traits: flower color and seed color. We need to find the percentage of offspring that have white flowers and green seeds. From the information provided, we know that 'yy' represents white flowers and 'GG' or 'Gg' represents green seeds.
Identify offspring with white flowers and green seeds Now, let's examine the Punnett square and identify the offspring with the genotype 'yyGG' or 'yyGg'.
The Punnett square is:
YG
Yg
yG
yg
YG
YYGG
YYGg
YyGG
YyGg
Yg
YYGg
YYgg
YyGg
Yygg
yG
YyGG
YyGg
yyGG
yyGg
yg
YyGg
Yygg
yyGg
yygg
We are looking for 'yyGG' and 'yyGg'.
From the Punnett Square, we can see:
yyGG appears once.
yyGg appears twice.
So, there are a total of 1 + 2 = 3 offspring with white flowers and green seeds.
Calculate the fraction of offspring The total number of offspring in the Punnett square is 16. Therefore, the fraction of offspring with white flowers and green seeds is 16 3 .
Convert the fraction to a percentage To express this fraction as a percentage, we multiply by 100: 16 3 × 100 = 18.75%
So, 18.75% of the offspring have white flowers and green seeds.
State the final answer The percentage of offspring with white flowers and green seeds is 18.75% . Comparing this to the given options, the closest answer is 18.7% .
Examples
Understanding the probability of certain traits appearing in offspring is crucial in agriculture. For example, a farmer might want to know the likelihood of producing plants with specific disease-resistant genes or desirable fruit characteristics. By using Punnett squares and probability calculations, they can make informed decisions about which plants to breed, maximizing their chances of obtaining the desired traits in their crops. This knowledge helps improve crop yields and reduces the need for pesticides or other interventions.
The percentage of offspring that have white flowers and green seeds is 18.7%. Therefore, the correct answer is option C. This was determined by analyzing the Punnett square for the specific genotypes and calculating the resultant fraction of the total.
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