Biology HW Chapter 14 (Due Apr 29, Test Apr 30)
Multiple Choice
Identify the choice that best completes the statement or answers the question.
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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. 2
b. 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.
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9. Which of the following form(s) a Barr body?
a. one of the Y chromosomes in a male cell
b. 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 IAIB
b. IBIB and IBi
c. IBIB and IAIB
d. IBi and ii
Blood Type
A
B
AB
O
Blood Types
Combination of Alleles
IAIA or IAi
IBIB or IBi
IAIB
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 O
b. 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. PP
b. Pp
c. P
d. p
____ 17. How many generations are shown in the pedigree in Figure 14–5?
a. 2
b. 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 disease
b. 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 fibrosis
b. 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 has been born
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. XY
b. 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. mutation
b. dominance
c. electrophoresis
d. nondisjunction
____ 30. Which of the following can be used to cut DNA so it can be studied?
a. restriction enzymes
b. 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 HaeIII
b. 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. biotechnology
b. 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. promoters
b. sex-linked genes
c. CFTR genes
d. autosomes
____ 35. About how much of our DNA encodes the instructions for building proteins?
a. 2 percent
b. 10 percent
c. 50 percent
d. 100 percent
____ 36. Which was the first step in sequencing the human genome?
a. locating overlapping sequences
b. 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 __________________________.