CHAPTER 13, HUMAN GENETICS QUIZ

_____1. Which of the following is Not true about a karyotype?
a) Homologous chromosomes are paired.
b) Sex chromosomes are identified separately from autosomes.
c) Chromosome pairs are numbered from smallest to largest.
d) Chromosome pairs are assorted by both size and shape.
e) Banding patterns are used in paring.

_____2. Karyotyping can be used to diagnose which of the following genetic disorders?
a) Down syndrome    b) phenylketonuria     c) neurofibromatosis     d) cystic fibrosis      e) hemophilia

_____3. Chorionic villus sampling uses what tissue to analyze the fetal cells and provide a karyotype?
a) fetal blood tissue
b) cells floating in the amniotic fluid
c) a small biopsy from the embryo itself but it readily heals
d) membrane tissue from the embryo side of the placenta
e) membrane tissue from the mother's side of the placenta

_____4. When homologous chromosomes fail to separate during meiosis, this is termed
a) cross over     b) RFLP     c) linked genes       d) disjunction     e) nondisjunction

_____5. Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis.
However, it is possible to assert that _____ results in nondisjunction in _____.
a) XXY; oogenesis
b) XXY; spermatogenesis
c) XXX; oogenesis
d) XYY; spermatogenesis
e) XO; oogenesis

_____6. In some cases of Down syndrome, there is a translocation between chromosomes
a) 21 and 13      b) 21 and 14       c) 21 and 18       d) 21 and 22         e) X and Y

_____7. Which statement is Not true about Down syndrome?
a) It is caused by a third copy of chromosome 21.
b) Greatly increased incidence occurs with fathers over age 35.
c) It is associated with chromosomal nondisjunction in meiosis.
d) Characteristics include mental retardation and extra eyelid folds.
e) Affected individuals have a considerably shortened life expectancy.

_____8. Considering that males are produced by Klinefelter (XXY) syndrome, XYY and normal XY chromosome combinations,
and females are produce by Turner (XO) syndrome, triple-X (XXX) and normal XX combinations, it is obvious that
a) maleness is caused by the presence of only one X chromosome.
b) femaleness is caused by the presence of two or more X chromosome.
c) maleness is caused by the minimal presence of one Y chromosome.
d) maleness occurs in the absence of two or more X chromosomes.
e) sex determination is a delicate balance between X and Y chromosomes.

_____9. Which genetic trait is Not associated with the chromosome involved in Down syndrome?
a) cataracts   b) mental retardation    c) Alzheimer disease    d) Cystic fibrosis     e) increase incidence of leukemia

_____10. Which one of these is caused by repeats of base triplets rather than a whole chromosome?
a) Down syndrome   b) Edward syndrome   c) Klinefelter syndrome    d) fragile-X syndrome   e) Turner syndrome

_____11. Which sex chromosome abnormally is correctly associated with the proper genotype?
a) Turner syndrome – XXY         b) triple-X – XO         c) Klinefelter syndrome - XXY

_____12. A male with underdeveloped testes, breast development, subnormal intelligence, and an abnormal karyotype is likely to have
a) Turner syndrome   b) Huntington disease    c) Klinefelter syndrome    d) Down syndrome    e) Edward syndrome

_____13. In a pedigree chart, which is correct?
a) Circles = males; Squares = females
b) A line between a circle and a square represents a mating.
c) A carrier with a normal phenotype is represented by a black circle or square.
d) Offspring are represented by triangles.

_____14. Which of the following diseases is not inherited as an autosomal recessive?
a) neurofibromatosis    b) Tay-Sachs disease    c) phenylketonuria    d) albinism    e) cystic fibrosis

_____15. Huntington disease is
a) caused by a mutated recessive gene on chromosome 21.
b) usually fatal before the individual reaches reproductive age.
c) usually inherited from a gene from the father.
d) due to a lack of an enzyme needed to metabolize phenylalanine, and damage can therefore be controlled by a diet lacking this amino acid.
e) All of the above are correct.

_____16. The most common lethal genetic disorder among Caucasians is
a) neurofibromatosis    b) Tay-Sachs disease    c) phenylketonuria    d) albinism    e) cystic fibrosis

_____17. Which of the following diseases is most prevalent in the Jewish community?
a) neurofibromatosis    b) Tay-Sachs disease    c) phenylketonuria    d) albinism    e) cystic fibrosis

_____18. Phenylketonuria is
a) caused by mutated gene on chromosome 12.
b) easily detested by high levels of phenylalanine in urine or blood.
c) the most common inherited disease of the nervous system.
d) due to a lack of an enzyme needed to metabolize phenylalanine, and damage can therefore be controlled by a diet lacking this amino acid.
e) All of the above are correct.

_____19. Which type of inheritance results in continuous variation - often a bell shaped curve - because genes at many loci are involved?
a) polygenic    b) autosomal dominant    c) autosomal recessive    d) X-linked    e) sex-influenced

_____20. Which is associated with the inability to produce factor VIII in the blood?
a) male pattern baldness
b) sickle-cell disease
c) color blindness
d) hemophilia
e) Duchenne muscular dystrophy

_____21. If the parents are AO and BO genotypes for the ABO blood group, their children could include which of the following genotypes?
a) AO and BO only
b) AO, BO and AB only
c) AA, BB and AB only
d) AO, BO, and OO only
e) AO, BO, AB and OO only

_____22. Which disease results in deformed red blood cells, poor circulation, and anemia?
a) male pattern baldness
b) sickle-cell disease
c) color blindness
d) hemophilia
e) Duchenne muscular dystrophy

_____23. Which provides protection against malaria in the heterozygote?
a) Duchenne muscular dystrophy
b) hemophilia
c) sickle-cell disease
d) male pattern baldness
e) color blindness

_____24. If a women is a carrier for the color-blindness recessive allele and her husband is normal, what are their chances that a son will be color blind?
a) None since the father is normal.
b) 50 percent since the mother is the only carrier.
c) 100 percent because the mother has the gene.
d) 25 percent because the mother is a hybrid.
e) None since he will also be just a carrier.

_____25. Autosomal dominant inheritance is shown by all but which of the following?
a) Marfan syndrome   b) color blindness   c) brachydactyly   d) hypercholesterolemia    e) achondroplastic dwarfism

_____26. Queen Victoria and some of her descendants carried an X-linked gene for
a) Duchenne muscular dystrophy
b) sickle-cell disease
c) hemophilia
d) male pattern baldness
e) color blindness

_____27. A genetic disorder (not counting disjunction) is more likely to be common in the population if it
does not manifest itself until after reproductive age has passed.
a) is recessive.
b) bestows some benefit in a heterozygous state.
c) is not sex-linked if recessive.
d) all of the above would increase the survival of a deleterious gene.

_____28. Which is inherited as a dominant in males but only expresses in the presence of testosterone?
a) pattern baldness
b) Duchenne muscular dystrophy
c) sickle-cell disease
d) color blindness
e) hemophilia

_____29. Which of the following is an X-linked condition?
a) Hemophilia    b) Tay-Sachs disease   c) Huntington's disease   d) Cystic fibrosis    e) Sickle-cell anemia

_____30. A child is diagnosed with Tat-Sachs disease. Which of the following organelles is most likely affected?
a) lysosome     b) ribosome    c) Golgi apparatus    d) rough endoplasmic reticulum    e) Peroxisomes

_____31. Human skin color is determined by three different genes working together to produce a wide range of possible
skin tones. This is an example of
a) Blending inheritance     b) Codominance     c) Polygenic trait     d) Polyploidy        e) Multiple alleles

_____32. In a pedigree, you notice that individuals who have a single parent with the condition have the condition themselves
50 percent of the time. Of the following, which condition has an inheritance pattern that best fits the description?
a) Tay-Sachs disease   b) Huntington's disease   c) Cystic fibrosis    d) Sickle-cell anemia    e) Phenylketonuria

_____33. The inheritance of skin color in humans is an example of which of the following?
a) Pleiotropy    b) Codominance   c) Epistasis    d) Polygenic inheritance    e) Gene linkage

_____34. From which parent(s) did a male with red-green color blindness inherit the defective allele?
a) Only the mother.
b) Only the father.
c) The mother or father, but not both.
d) Both the mother and the father.
e) It is impossible to determine with certainly using only the given information.

_____35. A human genetic defect that is caused by nondisjunction of the sex chromosomes is
a) Sickle-cell anemia   b) Hemophilia    c) Down syndrome    d) Turner syndrome    e) red-green color blindness

_____36. Duchenne's muscular dystrophy is inherited as a sex-linked recessive allele. From whom does a male with
this disease inherit the defective allele?
a) Only his mother.
b) Only his father.
c) The mother or father, but not both.
d) Both the mother and the father.
e) It is impossible to determine with certainly using only the given information.

_____37. Turner syndrome occurs in humans whose cells are missing the Y chromosome. all of the following are
True about Turner syndrome Except
a) A Turner syndrome zygote results when a sperm missing a Y chromosome fertilizes a normal egg.
b) A Turner syndrome zygote results when a normal sperm bearing an X chromosome fertilizes an egg missing an X chromosome.
c) During meiosis, nondisjunction occurs to produce one of the gametes used to form the Turner syndrome zygote.
d) The zygote has 45 chromosomes.
e) Barr bodies form in the nuclei of Turner syndrome individuals.

_____38. Color blindness in humans is
a) caused by a recessive allele
b) in equal proportion in both sexes
c) caused in females by a heterozygous genotype
d) caused in males by a homozygous genotype

_____39. A diagram in which several generations of a family and the occurrence of certain genetic characteristics are shown is called a
a) Punnett square    b) monohybrid cross   c) pedigree    d) family karyotype

_____40. Which of the following describes hemophilia?
a) multiple allele trait     b) dominant trait     c) sex-linked trait     d) codominant trait

_____41. Charts that show how a trait is inherited are called
a) Punnett squares      b) pedigrees      c) karyotype charts     d) genetic charts

_____42. A photograph that show chromosomes in homologous pairs is called a what?
a) karyotype        b) pedigree       c) phenotype         d) genotype

_____43. In a pedigree, a shaded circle or square indicates a person who has
a) an allele for a trait only.                  c) the trait as well as its allele.
b) a male allele.                                   d) a female allele.

_____44. Which of the following is shown in a karyotype?
a) a pedigree chart    b) DNA models    c) chromosomal abnormalities     d) ultrasound

_____45. Turner syndrome is a disorder in which a person has one X chromosome and
a) one Y chromosome                            c) two Y chromosomes
b) no other sex chromosome                  d) one other sex chromosome

_____46. An example of a disorder caused by a defective chromosome structure is
a) Klinefelter syndrome    b) Cri-du-chat syndrome    c) nondisjunction      d) Turner syndrome

_____47. People with Down syndrome are often prone to
a) heart defects    b) sterility    c) loss of hair     d) a cry that sounds like a cat

_____48. Males with Klinefelter syndrome may have
a) excessively hairy bodies                     c) no Y chromosome
b) large heads                                          d) breast development

_____49. A genetic disorder that causes secretion of mucus from some organs is
a) cystic fibrosis      b) Tay-Sachs disease      c) Huntington's disease       d) sickle-cell anemia

_____50. People with Huntington's disease develop deterioration of the
a) circulatory system      b) reproductive system      c) heart      d) nervous system

_____51. The allele for Tay-Sachs disease is found most often among
a) African Americans     b) Caucasians    c) Jewish people     d) Hispanic people

_____52. Sickle cell disease results in production of abnormal
a) nerve cells     b) hemoglobin     c) color vision     d) muscle tissue

_____53. Two examples of sex-linked disorders are.
a) hemophilia and color blindness             c) color blindness and sickle-cell anemia
b) hemophilia and cystic fibrosis               d) hemophilia and malaria

_____54. Phenylketonuria is a disorder that causes inability to use
a) hemoglobin       b) oxygen     c) a single amino acid     d) all proteins

_____55. Since the allele for colorblindness is located on the X chromosome, colorblindness
a) cannot be inherited                             c) occurs only in adults
b) is sex-linked                                      d) only occurs in females

_____56. If nondisjunction occurs,
a) there will be too many gametes produced
b) no gametes will be produced
c) a gamete will receive too many or too few homologues of a chromosome
d) mitosis cannot take place

_____57. Both sickle cell anemia and hemophilia
a) are caused by genes coding for defective protein       c) are seen in homozygous dominant individuals
b) provide resistance to malaria infection                       d) are extremely common throughout the world

_____58. If a characteristic is sex-linked it
a) occurs most common in males                        c) occurs only in females
b) can never occur in females                             d) is always fatal