The accompanying pedigree shows the transmission of a phenotyp...

Question

The accompanying pedigree shows the transmission of a phenotypic character. Using B to represent a dominant allele and b to represent a recessive allele,

Pedigree chart illustrating the inheritance of a phenotypic trait with symbols for dominant and recessive alleles.

Give the genotype(s) possible for each member of the family, assuming the trait is autosomal dominant.

Accepted Answer

Hi, everyone. Welcome back. Let's look at our next question. It says which of the following is true about excelling dominant conditions. Well, let's look at our answer choices. We've got choice. A males and females have an equal chance of inheriting them. Choice be it generally occurs more frequently in males than in females. Choice. See, it is not inheritable and choice. D it generally occurs more frequently in females than in males. Well, we can go ahead and eliminate right away choice. See, it is not inheritable. We're talking about a condition on the X chromosome and therefore it's going to be inherited. Now, this question is a little bit tricky because when we think about excellent traits, kind of the most famous ones, we often study in genetics are things like hemophilia which are excellent recessive traits. And those traits get seen more frequently in males because the male who has only one X chromosome will have the disease if he inherits one copy of the allele carrying the disease. But if it's a recessive condition, a female who has two X chromosomes will not show the disease. If she inherits just one copy, she would need to inherit two copies one from each parent. However, our question here is asking us about excellent dominant conditions. So in the case of a dominant condition, of course, an individual only needs one copy of the gene for the condition to be affected. So let's think this through in this case of female Who has two x chromosomes can inherit the condition from either parent since she gets an X chromosome from the mother and the father, A male. However, with only one x chromosome can only inherit the condition if the mother is affected, since a male, single X chromosome comes from the mother. So an affected father will never pass the condition on to his son. So in this case, you will see an excellent dominant condition more frequently in females who can inherit it from either parent. So our answer choice here is going to be choice D it generally occurs more frequently in females than in males. So we can go ahead and eliminate choice. A males and females have an equal chance of inheriting them. Since that's not the case and choice be, it generally occurs more frequently in males than in females as we discuss. That would be an excellent recessive trait that shows that characteristic. So choice B is not an answer. So once again, which of the following is true about excellent dominant conditions. Choice D it generally occurs more frequently in females than in males. See you in the next video.

The accompanying pedigree shows the transmission of a phenotypic character. Using B to represent a dominant allele and b to represent a recessive allele,

Give the genotype(s) possible for each member of the family, assuming the trait is autosomal dominant.

Key Concepts

Autosomal Dominance

Genotype vs. Phenotype

Pedigree Analysis

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