Question

question 6 of 20 : select the best answer for the question.
partially completed punnett square with columns labeled p, w and rows labeled w, w

1. refer to the partially completed punnett square. purple flowers (p) are dominant to white flowers (w). what do you predict about the flower color of the offspring resulting from this cross?

a. about 75 percent of the offspring will have purple flowers, and about 25 percent of the offspring will have white flowers.
b. about half of the offspring will have purple flowers, and about half of the offspring will have white flowers.
c. all of the offspring will have purple flowers.
d. about 75percent of the offspring will have white flowers, and about 25 percent of the offspring will have purple flowers.
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Explanation:

Step1: Analyze the Punnett square

The Punnett square has one parent with alleles \( P \) and \( w \) (top row) and the other parent with alleles \( w \) and \( w \) (left column). Let's complete the Punnett square:

• The first cell (row \( w \), column \( P \)): \( Pw \) (purple, since \( P \) is dominant)
• The second cell (row \( w \), column \( w \)): \( ww \) (white)
• The third cell (row \( w \), column \( P \)): \( Pw \) (purple)
• The fourth cell (row \( w \), column \( w \)): \( ww \) (white)

Step2: Count the phenotypes

Out of 4 possible offspring:

• Purple (\( Pw \)): 2
• White (\( ww \)): 2

So, the ratio of purple to white is \( \frac{2}{4} = 0.5 \) (50%) and \( \frac{2}{4} = 0.5 \) (50%).

Answer:

B. About half of the offspring will have purple flowers, and about half of the offspring will have white flowers.