The accompanying pedigree shows a family in which one child (II-1) has an autosomal recessive condition. On the basis of this fact alone, provide the following information.
What is the probability that all three of the children in generation II who have the dominant phenotype are Aa?

Question

The accompanying pedigree shows a family in which one child (II-1) has an autosomal recessive condition. On the basis of this fact alone, provide the following information.

Pedigree chart showing a family with one child affected by an autosomal recessive condition.

What is the probability that all three of the children in generation II who have the dominant phenotype are Aa?

Accepted Answer

Hi, everybody. Welcome back. Let's look at our next question. It says, what is the purpose of a pedigree chart? And we've got choice. A two track the inheritance of genetic traits within a family. Be to track the financial history of a family, C to track the social status of the family or D to track the medical history of the family. I think we can safely eliminate. Hopefully, it's not too hard to figure out, we can eliminate choice B to track the financial history of family and C to track the social status of a family. All that might be a colloquial meaning of someone's pedigree, but a pedigree chart specifically, um, we have two choices. Choice D says to track the medical history of a family. Well, this is partially true but not really a complete answer because specifically, you're looking for a genetic medical history, looking at how genetic traits are inherited. So that's why choice D isn't our correct answer. So our answer will be choice. A two track the inheritance of genetic traits within a family. Um, pedigree charts are very useful because they help to visualize patterns of inheritance of traits or diseases through multiple generations. And this can be important or this is important, I should say because that's how we determine, for instance, is something autism away or sex linked. If we see males and females affected equally, we can assume that the condition is on an auto zone. If we see now that well, if we know it's autism, now we would say, is it dominant or recessive? Well, a dominant trait would be seen in every generation since you only need one alittle, every affected child must have an affected parent. Whereas a recessive condition which could skip generations, you could have unaffected parents that are carriers of the recessive condition and then affected Children with a trait showing up in later generations. So those patterns of inheritance are easy to visualize and see when you lay out a pedigree chart. Um then this can be used to predict the probability of an individual inheriting a specific trait. Um and within the context of genetic counseling. So What is the purpose of a pedigree chart choice? A two track the inheritance of genetic traits with the family in the next video?

The accompanying pedigree shows a family in which one child (II-1) has an autosomal recessive condition. On the basis of this fact alone, provide the following information.

What is the probability that all three of the children in generation II who have the dominant phenotype are Aa?

Verified video answer for a similar problem:

Key Concepts

Autosomal Recessive Inheritance

Genotype Probability Calculation

Pedigree Analysis