question 2\ndear abby,\non march 18, 1995, ann landers printed a letter from a man who was upset because he…

question 2\ndear abby,\non march 18, 1995, ann landers printed a letter from a man who was upset because he and his wife both brown - eyed had a \gorgeous 7 month old daughter with the brightest blues eyes i have ever seen.\ the father continues, \although i love my daughter with all my heart, i still have some doubts that she is my biological child when i look into her beautiful blue eyes.\\nwhat are the chances that their second child will have blue eyes? (hint: show the process on a piece of paper by conducting a simple punnet square. brown eyes are dominant, blue are recessive).\na 0\nb 25%\nc 50%\nd 100%
Answer
Explanation:
Step1: Determine parental genotypes
Since both parents have brown - eyes and they had a blue - eyed child, their genotypes must be heterozygous. Let B represent the dominant brown - eye allele and b represent the recessive blue - eye allele. So the parents' genotypes are Bb.
Step2: Set up Punnett Square
The possible gametes from each parent are B and b. The Punnett Square has 4 boxes. The top row has B and b (gametes from one parent), and the left - hand column has B and b (gametes from the other parent).
Step3: Fill in Punnett Square
When we fill in the Punnett Square: BB, Bb, Bb, bb.
Step4: Calculate probability
The genotype bb results in blue eyes. Out of 4 possible genotypes, 1 is bb. So the probability is $\frac{1}{4}$ or 25%.
Answer:
B. 25%