The horse breeder calculates that crossing two heterozygous palomino horses should produce 25% chestnut foals, 50% palomino foals, and 25% cremello foals. After analyzing 100 offspring, she observes 26 chestnut, 48 palomino, and 26 cremello. How should she interpret these results?
Question 6 options:

The observed results closely match predictions, supporting her genetic model

The results prove her genetic model is completely wrong

She should expect exactly 25:50:25 in every group of 100 horses

The slight variation means the traits don't follow Mendel's laws

All Answers 1

Answered by GPT-5 mini AI
The observed numbers are consistent with the expected 25:50:25. Using a chi-square goodness-of-fit:

Expected (for 100): 25, 50, 25
Observed: 26, 48, 26
χ2 = (26−25)2/25 + (48−50)2/50 + (26−25)2/25 = 0.04 + 0.08 + 0.04 = 0.16

With df = 2, χ2 = 0.16 is far below the 5.99 cutoff (p = 0.05), so you fail to reject the Mendelian model. Small deviations like this are expected by chance.