Biology HW Chapter 14 (Due Apr 29, Test Apr 30)
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 1. Human females produce egg cells that have
a. / one X chromosome.b. / two X chromosomes.
c. / one X or one Y chromosome.
d. / one X and one Y chromosome.
____ 2. What percentage of human sperm cells carry an X chromosome?
a. / 0%b. / 25%
c. / 50%
d. / 100%
____ 3. A human female inherits
a. / two copies of every gene located on the X chromosome.b. / twice as many sex chromosomes as a human male inherits.
c. / one copy of every gene located on the Y chromosome.
d. / all of the same genes that a human male inherits.
____ 4. How many chromosomes are shown in a normal human karyotype?
a. / 2b. / 23
c. / 44
d. / 46
____ 5. Sex-linked genes are located on
a. / the autosomal chromosomes.b. / the X chromosome only.
c. / the Y chromosome only.
d. / both the X chromosome and the Y chromosome.
____ 6. Colorblindness is more common in males than in females because the allele for colorblindness is
a. / dominant and located on the X chromosome.b. / recessive and located on the Y chromosome.
c. / recessive and located on the X chromosome.
d. / recessive and located on the Y chromosome.
____ 7. Which of the following statements is true?
a. / Females cannot have hemophilia.b. / A colorblind girl’s father must be colorblind.
c. / A sex-linked allele cannot be dominant.
d. / A colorblind boy’s father must be colorblind.
____ 8. Human males have
a. / one X chromosome only.b. / two X chromosomes.
c. / one X and one Y chromosome.
d. / two Y chromosomes.
____ 9. Which of the following form(s) a Barr body?
a. / one of the Y chromosomes in a male cellb. / one of the X chromosomes in a male cell
c. / one of the X chromosomes in a female cell
d. / both of the X chromosomes in a female cell
____ 10. The formation of a Barr body inactivates
a. / half of the genes on one X chromosome in a female cell.b. / one whole X chromosome in a female cell.
c. / one whole Y chromosome in a male cell.
d. / one gene on one X chromosome in a male cell.
____ 11. A cat that has spots of more than one color
a. / has no Barr bodies.b. / is probably female.
c. / is probably male.
d. / could be male or female.
____ 12. Which of the following pairs of genotypes result in the same phenotype?
a. / IAIA and IAIBb. / IBIB and IBi
c. / IBIB and IAIB
d. / IBi and ii
Blood Types
Blood Type / Combination of Alleles
A / IAIA or IAi
B / IBIB or IBi
AB / IAIB
O / ii
Figure 14–2
____ 13. If a man with blood type A and a woman with blood type B produce an offspring, what might be the offspring’s blood type?
a. / AB or Ob. / A, B, or O
c. / A, B, AB, or O
d. / AB only
Figure 14–3
____ 14. The trait in the pedigree chart in Figure 14–3 is dominant. Therefore, we can tell from the chart that in the couple labeled 2
a. / the male is heterozygous and the female is homozygous.b. / the male is homozygous and the female is heterozygous.
c. / the male is homozygous and the female is homozygous.
d. / the male is heterozygous and the female is heterozygous.
Figure 14–4
____ 15. In a pedigree, such as the one in Figure 14–4, a circle represents a(an)
a. / male.b. / female.
c. / child.
d. / adult.
Figure 14–5
____ 16. The trait in pedigree in Figure 14–5 has two alleles: P (dominant) and p (recessive). The black symbols show the dominant phenotype, and the white symbols show the recessive phenotype. What is the genotype of individual number 1?
a. / PPb. / Pp
c. / P
d. / p
____ 17. How many generations are shown in the pedigree in Figure 14–5?
a. / 2b. / 4
c. / 6
d. / 8
____ 18. If the allele for having a white forelock is dominant, family members WITHOUT a white forelock are
a. / homozygous recessive.b. / heterozygous.
c. / homozygous dominant.
d. / trisomal.
Figure 14–6
____ 19. For the pedigree in Figure 14–6, shaded symbols represent afflicted people. Males are squares; women are circles. If the trait is a sex-linked trait carried on the X chromosome, what is true about the mother represented by circle 1?
a. / She has two alleles for the disorder.b. / She has one allele for the disorder.
c. / She has no alleles for the disorder.
d. / She has the genotype XXY.
____ 20. Which of the following is caused by a dominant allele?
a. / Huntington’s diseaseb. / colorblindness
c. / cystic fibrosis
d. / sickle-cell disease
____ 21. Which of the following diseases and conditions does not appear until late in a person’s life?
a. / cystic fibrosisb. / sickle cell disease
c. / colorblindness
d. / Huntington disease
____ 22. In cystic fibrosis, a change in a single gene causes the protein called CFTR to
a. / become less soluble.b. / fold improperly.
c. / destroy the cell membrane.
d. / transport sodium ions.
____ 23. Compared with normal hemoglobin, the hemoglobin of a person with sickle cell disease is
a. / longer.b. / shorter.
c. / less soluble.
d. / more soluble.
____ 24. People who are heterozygous for sickle cell disease are generally healthy because they
a. / are resistant to many different diseases.b. / have some normal hemoglobin in their red blood cells.
c. / are not affected by the gene until they are elderly.
d. / produce more hemoglobin than they need.
____ 25. The failure of chromosomes to separate during meiosis is called
a. / nondisjunction.b. / X-chromosome inactivation.
c. / Turner’s syndrome.
d. / Down syndrome.
____ 26. Because the X chromosome contains genes that are vital for normal development, no baby hasbeenborn
a. / with one X chromosome.b. / with three X chromosomes.
c. / without an X chromosome.
d. / with four X chromosomes.
____ 27. Which of the following combinations of sex chromosomes represents a female?
a. / XYb. / XXY
c. / XXXY
d. / XX
____ 28. If nondisjunction occurs during meiosis,
a. / only two gametes may form instead of four.b. / some gametes may have an extra copy of some genes.
c. / the gamete cannot join another to form a organism.
d. / the gametes redistribute chromosomes after meiosis.
Figure 14–7
____ 29. What is illustrated in Figure 14–7?
a. / mutationb. / dominance
c. / electrophoresis
d. / nondisjunction
____ 30. Which of the following can be used to cut DNA so it can be studied?
a. / restriction enzymesb. / gel electrophoresis
c. / karyotypes
d. / haplotypes
____ 31. Which piece of DNA would move fastest in gel electrophoresis? A segment that is
a. / 100 base pairs long.b. / 1,000 base pairs long.
c. / 5,000 base pairs long.
d. / 100,000 base pairs long.
Figure 14–8
____ 32. Which enzyme(s) in Figure 14–8 would be best for cutting DNA to make fragments with sticky ends?
a. / EcoRI and HaeIIIb. / HaeIII and BamI
c. / HaeIII alone
d. / EcoRI and BamI
Figure 14–9
____ 33. What new field is described by the overlap area in the Venn diagram in Figure 14–9?
a. / biotechnologyb. / bioinformatics
c. / gene therapy
d. / genetic engineering
____ 34. What did scientists in the Human Genome Project look for in DNA to identify the locations of genes?
a. / promotersb. / sex-linked genes
c. / CFTR genes
d. / autosomes
____ 35. About how much of our DNA encodes the instructions for building proteins?
a. / 2 percentb. / 10 percent
c. / 50 percent
d. / 100 percent
____ 36. Which was the first step in sequencing the human genome?
a. / locating overlapping sequencesb. / identifying genes by finding promoters
c. / cutting the DNA into manageable pieces
d. / sorting between introns and exons
____ 37. The Human Genome Project is an attempt to
a. / sequence every person’s DNA.b. / sequence the DNA of every human gene.
c. / cure infectious human diseases.
d. / identify all restriction enzymes.
____ 38. The human genome was sequenced
a. / by sequencing each gene on each chromosome, one at a time.b. / in order of the chromosome number on a karyotype.
c. / by finding overlapping regions between sequenced DNA fragments.
d. / by first organizing all the single-base differences into haplotypes.
____ 39. More than forty percent of the proteins coded for in the human genome are
a. / used to help protect the DNA.b. / coded for on the X and Y chromosomes
c. / thought to have the same function.
d. / similar to proteins found in other organisms.
____ 40. What prevents insurance companies from discriminating against people based on information derived from genetic tests?
a. / Only scientists can read the results of complicated genetic tests.b. / Genetic tests don’t show information about genetic disorders.
c. / Discrimination based on genetic information is against the law.
d. / People with genetic diseases cannot do business with private insurance companies.
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____ 41. In humans, the mother’s gamete determines the sex of the offspring. ______
____ 42. In a human karyotype, 44 of the chromosomes are autosomes. ______
____ 43. To make a karyotype, biologists take pictures of cells during mitosis, when they are condensed and easier to view. ______
____ 44. A recessive X-linked trait would be more common in males than in females. ______
____ 45. Two parents who have Huntington disease may produce an offspring who does not have Huntington disease. ______
Figure 14–10
____ 46. The pedigree chart in Figure 14-10 shows that some people can be carriers of the trait without being afflicted. This means the allele for the trait is dominant. ______
____ 47. A person who has Down syndrome has two copies of chromosome 21. ______
____ 48. Down syndrome, Turner’s syndrome, and Klinefelter’s syndrome are all caused by nondisjunction. ______
____ 49. When DNA fragments are separated by gel electrophoresis, the longest fragments move fastest. ______
____ 50. A haplotype is a group of alleles found on the same chromosome that tend to be inherited all together. ______
Completion
Complete each statement.
51. In humans, sex is determined by the X and ______chromosomes.
52. If a couple has five boys, the probability that the next child will be a boy is ______.
53. A(An) ______can be used to determine whether a person has inherited the normal number of chromosomes.
54. A Barr body is an inactivated ______chromosome.
55. The alleles IA and ______for the AB blood group are codominant.
56. A person who has blood type O can safely receive a blood transfusion only from a person who has blood type ______.
57. A(An) ______is a diagram that follows the inheritance of a single gene through several generations of a family.
Figure 14–3
58. The allele for the trait illustrated in the pedigree chart in Figure 14–3 is dominant. The probability of the couple labeled 2 in the pedigree having a child without the trait is ______percent.
59. An advantage of using a restriction enzyme such as EcoR1 is that it creates ______that can match to complimentary base pairs.
60. The law that protects people from being discriminated against because of information learned in genetic tests is called the ______.