Question

In: Biology

A man is heterozygous for achondroplasia for which the autosomal dominant A allele confers extremely short...

A man is heterozygous for achondroplasia for which the autosomal dominant A allele confers extremely short stature. His wife's genotype is aa and she is normal height. They have five children together. What is the probability that any two of their five children will have the short stature phenotype, in any birth order?

Expert Solution

solution:

The probability is 5/16 that any two of their five children will have the short stature phenotype.

Explanation:

As man is heterozygous for achondroplasia (Aa) and and his wife has normal genotype (aa). So there is 50% chance of child having normal genotype and 50% chances of child with achondroplasia.

	a	a
A	Aa	Aa
a	aa	aa

50% or 1/2 = Aa;

50%or 1/2 = aa

To calculate the probability we use binomial theorem:

Let's assign probabilities to each having the achondroplasia, n= 5 no. Of children

a = child having achondroplasia = 1/2 (Aa)

b = normal child =1/2 (aa)

The expanded binomial for the value of n=5

(a+b)5 = a5 + 5a4b+10a3b2+10a2b3+5ab4+b5

As each term represents a possible outcome. The term describing the outcome of two achondroplasia (short stature) children and three normal children, the expression of probability is

p = 10a2b3

= 10(1/2)2(1/2)3

= 10(1/2)5

= 10(1/32) = 10/32 = 5/16

p = 5/16

The probability is 5/16 that two children out of five will have the short stature phenotype.

gladiator answered 1 year ago

If there is an affected heterozygous parent with Huntington’s disease (an autosomal dominant disease) who has...

If there is an affected heterozygous parent with Huntington’s disease (an autosomal dominant disease) who has children with an unaffected parent, what are the chances of them having kids with Huntington’s disease? If there are two parents who are heterozygous carriers for Cystic Fibrosis disease (an autosomal recessive disease) What are the chances of them having a child with Cystic Fibrosis disease? What are the chances of them having a child who is a carrier for Cystic Fibrosis? What are...

Huntington's Disease is caused by an autosomal dominant allele. Suppose a prospective father is diagnosed with...

Huntington's Disease is caused by an autosomal dominant allele. Suppose a prospective father is diagnosed with this disease. His own mother also had it, but not his father. The prospective mother has no family history of the disease. a. What are the genotypes of these two prospective parents? (Tell how many copies of the dominant Huntington's allele the man and the woman each has.) b. What is the probability that a child of theirs would inherit the disease? Explain.

Huntington disease is a rare neurodegenerative human disease determined by an autosomal dominant allele. (Because it...

Huntington disease is a rare neurodegenerative human disease determined by an autosomal dominant allele. (Because it is a rare disease, homozygous individuals are also rare.) The disorder is typically a late onset disease with symptoms appearing after the age of 30. A young man has learned that his father has developed the disease. What is the probability that the young man will also develop the disease? What is the probability that a child of the young man develops the disease?

Huntington is a dominant disorder. A man is heterozygous for the Huntington gene (Hh). He marries...

Huntington is a dominant disorder. A man is heterozygous for the Huntington gene (Hh). He marries a woman who is (Hh). Will the man or woman develop the disease? What is the probability that their first child will develop the disease? Draw a Punnet Square.

12. If a heterozygous dominant tall pea is crossed with a short plant, what is the...

12. If a heterozygous dominant tall pea is crossed with a short plant, what is the expected phenotype ratio? 13. Give three examples of phenotypes. 14. Why is skin color classified as polygenic inheritance? 15. If the parental genotype is EeWw, what are the potential allele combinations that could occur at the end of meiosis? 16. During DNA replication, a DNA strand with the bases CTAGGT will produce what complimentary strand of bases? 17. In their experiment, what would Hershey...

Which of the following is not a situation in which a loss-of-function allele may be dominant...

Which of the following is not a situation in which a loss-of-function allele may be dominant to the wildtype allele? a) the wildtype allele is haplosufficient b) the wildtype allele is haploinsufficient c) the loss-of-function protein forms a nonfunctional complex with the wildtype protein d) the loss-of-function protein competes with the wildtype protein to bind a DNA target e) the loss-of-function protein sequesters a substrate

In a snail, an autosomal allele causing a banded shell (b) is recessive to the allele...

In a snail, an autosomal allele causing a banded shell (b) is recessive to the allele for unbanded shell (B). Genes at a different locus on the same chromosome determine the background color of the shell; here, yellow (y) is recessive to brown (Y). The genes for shell banding and background color have a recombination frequency of 0.25. A banded, yellow snail is crossed with a homozygous brown, unbanded snail. The F1 are then crossed with banded, yellow snails (a...

In elephants, the allele for the prehensile trunk, T is dominant over the allele for a...

In elephants, the allele for the prehensile trunk, T is dominant over the allele for a non-grasping trunk, t; the allele for floppy ears, E is dominant over the allele for pointy ears, e; and the allele for pointy tusks, P is dominant over the allele for blunt tusks. If you were to cross a trihybrid elephant with a pure-breeding elephant with a prehensile trunk, pointy ears, and blunt tusks, what proportion of the offspring would have a genotype of...

Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the...

Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the fingers and toes are shortened. In a population of 10,000 people, 1,600 are BB, 4,800 are Bb, and 3,600 are bb. A)What percentage of people in this population have short fingers and toes? B)What is the frequency of the b allele? C)Is this population in Hardy-Weinberg equilibrium?

what does it mean when it says, " an allele confers with a phenotype" ? I...

what does it mean when it says, " an allele confers with a phenotype" ? I need a synonym or different short simple explanation of this statement.