AaAaAaAaTest Bank forChapter 6: Pedigree Analysis, Applications, and Genetic TestingTest Bank for Chapter 6: Pedigree Analysis, Applications, and Genetic TestingMultiple-Choice Questions1. Two parents are phenotypically normal, but one of their four biological children has a typical autosomal recessive trait. The other three children are phenotypically normal. It is very likelythata. the affected child is a girl.b. the affected child is a boy.c. the trait was expressed by one of the grandparents of the children.d. the parents are both heterozygous for the trait.e. if the affected child eventually marries a phenotypically normal spouse, all of the their children will have the trait.Answer: dSection 6.2Comprehension Question2. Which of the following descriptions of a Y-linked trait in humans is correct?a. All the sons of an affected father will be affected with the trait.b. Half the sons of a mother whose father was affected with the trait will be affected.c. Half the sons of an affected father will not be affected with the trait and the other half will be infertile.d. All the daughters of an affected father will be phenotypically normal themselves but half of their own sons will be affected with the trait.e. The parents of an affected man likely were both phenotypically normal.Answer: aSection 6.2Comprehension Question3. Which of the following statements is incorrect concerning an X-linked recessive trait in humans?a. An affected man often has phenotypically normal parents.b. All the sons of an affected woman will be expected to be affected.c. An affected woman almost always has an affected mother.d. An affected man usually has a mother who carries the recessive allele.e. A phenotypically normal woman whose father was affected is likely to be heterozygous for the condition.Answer: cSection 6.2Comprehension Question4. In pedigree analysis, consanguinity refers toa. mating between two heterozygous carrier parents.b. the realization that phenotypes between children and grandparents being often more closely related than between children and parents.c. mating between two closely related parents.d. a situation where the children of two parents are adopted.e. a situation where only one individual in the entire pedigree is affected with the trait or disorder.Answer: cSection 6.2Comprehension Question5. In pedigree analysis, the proband isa. the individual having the trait or disorder from whom the pedigree is initiated.b. the medical geneticist who analyzes the pedigree to find the mode of inheritance for the disorder.c. the parents of the first child in the family to show the trait or disorder.d. one of the grandparents or great grandparents who are in the first generation of the pedigree.e. the most common software package that geneticists use to analyze pedigrees.Answer: aSection 6.2Comprehension Question6. Which term refers to mating between closely related people?a. Consanguinityb. Probandingc. Congenital d. Concordancee. DiscordanceAnswer: aSection 6.2Comprehension Question7. Which of the following is not a typical characteristic of human traits that follow an autosomal recessive inheritance pattern?a. They often “skip” generations.b. They appear equally in males and females.c. Parents of affected children are often phenotypically normal themselves.d. When affected individuals marry phenotypically normal individuals, their children are often phenotypically normal. e. All of the above are characteristic of autosomal recessive inheritance. Answer: eSection 6.2Comprehension Question8. Which of the following is not a characteristic of X-linked recessive traits in humans?a. More males than females affected.b. Approximately one-half of the sons of a female carrier are affected.c. They cannot be passed from father to son.d. Phenotypically normal daughters of affected men are always carriers.e. Affected daughters always have an affected mother. Answer: eSection 6.2Comprehension Question9. Most pedigrees showing the hypothetical human trait show the following characteristics:- Males and females are equally affected.- Two unaffected parents can have an affected child.- In families in which the parents are unaffected but the children are affected, 1/4 of the children are affected.What is the most likely mode of inheritance for this disorder?a. Autosomal recessiveb. Autosomal dominantc. X-linked recessived. X-linked dominante. Y-linkedAnswer: aSection 6.2Comprehension Question10. Most pedigrees showing the hypothetical human trait show the following characteristics:- If a phenotypically normal woman with an affected father has children with an unaffectedman, half of the sons and none of the daughters are affected.- Affected females always have an affected father and an affected maternal grandfather.- The trait is never passed from father to son.What is the most likely mode of inheritance for this disorder?a. Autosomal recessiveb. Autosomal dominantc. X-linked recessived. X-linked dominante. Y-linkedAnswer: aSection 6.2Comprehension Question11. Most pedigrees showing the hypothetical human trait show the following characteristics:- Only males are affected.- Affected fathers always pass the trait to sons.What is the most likely mode of inheritance for this disorder?a. Autosomal recessive b. Autosomal dominantc. X-linked recessived. X-linked dominante. Y-linkedAnswer: eSection 6.2Comprehension Question12. Most pedigrees showing the hypothetical human trait show the following characteristics:- Females are affected twice as frequently as males.- Affected fathers may have affected daughters but never affected sons.- Half the children of affected mothers and normal fathers are affected.What is the most likely mode of inheritance for this disorder?a. Autosomal recessive b. Autosomal dominantc. X-linked recessived. X-linked dominante. Y-linkedAnswer: dSection 6.2Comprehension Question13. The ability to roll the tongue is caused by a dominant allele. A woman is a “roller,” but one ofher parents is not. What is the woman’s genotype?a. Homozygous dominantb. Heterozygousc. Homozygous recessived. Either homozygous recessive or homozygous dominante. Cannot be determined from this informationAnswer: bSection 6.2Application Question14. The ability to roll the tongue is caused by a dominant allele. A woman is a “roller,” but one of her parents is not. The woman is expecting a child with a man who is a “nonroller.” What is the probability that their first child will be a “roller”?a.