Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
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Chapter 2, Problem 46P
Explain why disease alleles for cystic fibrosis (CF) are recessive to the normal alleles (CF+), yet the disease alleles responsible for Huntington disease (HD) are dominant to the normal alleles (HD+).
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Students have asked these similar questions
Explain why disease alleles for cystic fibrosis (CF)are recessive to the normal alleles (CF+), yet thedisease alleles responsible for Huntington disease(HD) are dominant to the normal alleles (HD+).
In addition to the allelic pair determining pattern baldness in man (B,b), consider early baldness to be due to another autosomal allele (E) on a different pair of chromosomes and also dominant in males but recessive in females. The phenotype for ee may be late or nonbaldness depending on sex and the genotype for B, b alleles. Two doubly heterozygous persons marry.
What is the phenotype of the male parent?
What is the phenotype of the female parent?
Give the phenotypic ratio expected among male children of couples such as this one. Show corresponding genotypes for each phenotype mentioned in your phenotypic ratio.
Give the phenotypic ratio expected among female children of couples such as this one. Show corresponding genotypes for each phenotype mentioned in your phenotypic ratio.
1. A) Apply the concept of sex linkage to explain why color
blindness is more prevalent in men than in women. B)
Mary is concerned that she may be a carrier for
hemophilia, a sex-linked condition located on the X
chromosome. Mary is married to John, who doesn't have
hemophilia. Assuming Mary is a carrier, what are the
genotype ratios expected for Mary and John's kids
(specify for boys and for girls)? C) Mary and John have 2
boys, none of them has hemophilia. Can we use this fact
as proof that Mary does not carry the allele for
hemophilia? Explain your argument.
Chapter 2 Solutions
Genetics: From Genes to Genomes
Ch. 2 - For each of the terms in the left column, choose...Ch. 2 - During the millennia in which selective breeding...Ch. 2 - Describe the characteristics of the garden pea...Ch. 2 - An albino corn snake is crossed with a...Ch. 2 - Two short-haired cats mate and produce six...Ch. 2 - Piebald spotting is a condition found in humans in...Ch. 2 - As a Drosophila research geneticist, you keep...Ch. 2 - A mutant cucumber plant has flowers that fail to...Ch. 2 - In a particular population of mice, certain...Ch. 2 - In humans, a dimple in the chin is a dominant...
Ch. 2 - Some inbred strains of the weedy plant Arabidopsis...Ch. 2 - Among Native Americans, two types of earwax...Ch. 2 - Imagine you have just purchased a black stallion...Ch. 2 - If you roll a die singular of dice, what is the...Ch. 2 - In a standard deck of playing cards, four suits...Ch. 2 - How many genetically different eggs could be...Ch. 2 - What is the probability of producing a child that...Ch. 2 - A mouse sperm of genotype a B C D E fertilizes an...Ch. 2 - Your friend is pregnant with triplets. She thinks...Ch. 2 - Galactosemia is a recessive human disease that is...Ch. 2 - Albinism is a condition in which pigmentation is...Ch. 2 - A cross between two pea plants, both of which grew...Ch. 2 - A third-grader decided to breed guinea pigs for...Ch. 2 - The self-fertilization of an pea plant produced...Ch. 2 - The achoo syndrome sneezing in response to bright...Ch. 2 - A pea plant from a pure-breeding strain that is...Ch. 2 - The following table shows the results of different...Ch. 2 - A pea plant heterozygous for plant height, pod...Ch. 2 - In the fruit fly Drosophila melanogaster, the...Ch. 2 - Based on the information you discovered in the...Ch. 2 - Considering the yellow and green pea color...Ch. 2 - What would have been the outcome the genotypic and...Ch. 2 - Recall that Mendel obtained pure-breeding with...Ch. 2 - The gene that likely controlled flower color...Ch. 2 - For each of the following human pedigrees,...Ch. 2 - Consider the pedigree that follows for cutis laxa,...Ch. 2 - A young couple went to see a genetic counselor...Ch. 2 - Huntington disease is a rare fatal, degenerative...Ch. 2 - Is the disease shown in the following pedigree...Ch. 2 - Figure 2.22 shows the inheritance of Huntington...Ch. 2 - Consider the cystic fibrosis pedigree in Figure...Ch. 2 - Prob. 42PCh. 2 - People with nail-patella syndrome have poorly...Ch. 2 - Midphalangeal hair hair on top of the middle...Ch. 2 - A man with Huntington disease he is heterozygous...Ch. 2 - Explain why disease alleles for cystic fibrosis CF...Ch. 2 - The following pedigree shows the inheritance of...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Imagine you have a blood group of "X" which is recessive and expressed by xx. The dominant blood groups are Y and Z, where homozygous of these alleles are expressed as YY and ZZ, respectively. What will be the genotype of your parents blood group? Why? Please explain in your own words. [Max 200 words]arrow_forward—Hereditary canine spinal muscular atrophy (HCSMA) is a motor neuron disease in Brittany Spaniels. Breeding studuies within a kindred of more than 125 dogs (Brittany spaniel and beagle-Brittany outcrosses) have established an autosomal dominant inheritance for HCSMA. Which of the following genotypes would cause the dog to NOT HAVE HCSMA? Hh HH Hh A and C B and C– —(see question above for genotype) is a spaniel who is homozygous recessive for the HCSMA trait had a puppy with a spaniel who was heterozygous for this trait, what is the probability that the puppy would be normal? 0% 25% 50% 75% 100%arrow_forwardCystic Fibrosis (CF) is an autosomal recessive condition. Therefore, heterozygous (Cc) carriers do not display symptoms. Two parents who are carriers plan to start a family and you are a genetic counselor helping to advise them about their chances of having children affected by CF. a) Suppose the couple has 4 children, each one year apart. What is the probability that all 4 children will inherit CF? b) What is the probability that any 3 of their 4 children will not inherit CF, but 1 will be affected? c) What is the probability that their first child will not inherit CF, but the younger 3 children will inherit CF?arrow_forward
- Why the allele for Huntington disease is dominant?arrow_forwardIn humans, the allele for normal blood clotting, H, is dominant to the allele for hemophilia, h. This is a sex-linked trait found on the X chromosome. A woman with normal blood clotting has four children: a normal son, a hemophiliac son, and two normal daughters. The father has normal blood clotting. What is the genotype for each member of the family?arrow_forwardHuntington disease is a rare dominant condition in humans that results in a slow but inexorable deterioration of the nervous system. The disease shows what might be called age-dependent penetrance, which is to say that the probability that a person with the Huntington genotype will express the phenotype varies with age. Assume that 50% of those inheriting the HD allele will express the symptoms by age 40. Susan is a 35-yearold woman whose father has Huntington disease. She currently shows no symptoms. What is the probabbility that Susan will show symptoms in five years?arrow_forward
- Explain why Huntington disease is inherited as adominant allele while cystic fibrosis is caused by arecessive allele.arrow_forwardWhat kind of polymorphism is most likely represented?arrow_forwardCystic fibrosis in humans is caused by a recessive allele. A man is known to be a carrier of the cystic fibrosis allele. He marries a phenotypically normal woman. In the general population, the incidence of cystic fibrosis at birth is approximately 1 in 1,700. Assume Hardy-Weinberg proportions. What is the probability that the wife is also a carrier? Answer in decimal number only (three decimal places; example: 0.123). What is the probability that their first child will be affected? Answer in decimal number only (three decimal places; example: 0.123).arrow_forward
- 15. The following pedigree shows inheritance of Huntington's disease, a fatal genetic disorder that causes neurodegeneration. Since signs and symptoms usually do not appear until adulthood, many who are carriers may not realize their risk of passing on the disease-causing allele. The following pedigree represents a family in which some people are affected by Huntington's disease. Reeessive Trit er btmnt be Mec yplicalty Hinheteearrow_forwardEpilepsy is a central nervous system (neurological) disorder in which brain activity becomes abnormal, causing seizures or periods of unusual behavior, sensations and sometimes loss of awareness. For epilepsy, the concordance values are 72% for monozygotic twins and 15% for dizygotic twins. 1) Is this a single gene inheritance or multifactorial disease? 2) Is there a strong genetic or environmental cause to the development of this disease? If both genetic and environmental causes are implicated, you have to indicate each of them separately.arrow_forwardTo determine: The reason for the fact alleles that causes cystic fibrosis (CF) are recessive to the normal alleles (CF*) whereas disease alleles are causing Huntington disease (HD) aredominant to the normal alleles (HD*).arrow_forward
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