Further Reflection

Back at the lab table, the group compares their final computations.

Ana: ‘So the chance that exactly one out of four kids is affected is about 42.2%. With this real family, it happened that they got exactly one aa child, two carriers, and one fully unaffected. That outcome aligns with the math.’

You: ‘Seeing the binomial formula verified by an actual family example cements the concept for me. It’s a relief to know the logic holds in real-life scenarios.’

Michael: ‘We also need to remember that just because it’s 42.2% doesn’t guarantee that’s the distribution in every set of four births. Probability indicates likelihood, not certainty.’

Dr. Antoniou: ‘Precisely. Genetics is about probabilities, not absolutes. As you all practice more problems, you’ll feel increasingly confident distinguishing between the multiplication, addition, and binomial rules. Excellent work today.’

She shows a chart that highlights multiple family members affected by CF. One individual is labeled with a question mark, suggesting possible chromosomal involvement. She looks at the students and asks them to consider the logical next step. 

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