GENETICS CHAP 10-12
True/False
____ 1. Homologous chromosomes are two chromosomes with identical DNA sequences.
____ 2. Recent research suggests that beneficial mutations accumulate faster when species undergo sexual reproduction rather than asexual reproduction.
____ 3. Sexual reproduction would be more advantageous than asexual reproduction for organisms living in an environment that is diverse and undergoes frequent changes.
____ 4. The separation of genes during crossing over occurs more frequently between genes that are far apart on a chromosome than for genes that are close together.
____ 5. During meiosis I, homologus chromosome pairs are separated when the centromeres split apart.
____ 6. Gregor Mendel’s research supports the idea each organism carries a pair of alleles.
____ 7. Griffith’s experiment with R and S strain Streptococcus pneumoniae showed that DNA is the genetic material of the cell.
____ 8. The central dogma means that environmental factors have no influence on the transcription and translation of genes.
____ 9. The enzymes involved in DNA replication are named for the tasks they perform.
____ 10. DNA is a structurally simpler molecule than protein.
____ 11. A white mouse whose parents are both white produces only brown offspring when mated with a brown mouse. The white mouse is most probably ____.
a. / homozygous recessive / c. / homozygous dominantb. / heterozygous / d. / haploid
____ 12. In mink, brown fur color is dominant to silver-blue fur color. If a homozygous brown mink is mated with a silver-blue mink and 8 offspring are produced, how many would be expected to be silver-blue?
a. / 0 / c. / 6b. / 3 / d. / 8
Figure 10-8
____ 13. In Figure 10-8, which set of chromatids illustrates the result of a single crossover of the homologous chromosomes?
a. / A / c. / Cb. / B / d. / D
____ 14. In Figure 10-8, which set of chromatids will result if each chromatid crossed with a nonsister chromatid?
a. / A / c. / Cb. / B / d. / D
____ 15. Crossing over would most likely occur during which stage of the cell cycle?
a. / when DNA is being replicatedb. / when homologous chromomosomes line up in pairs
c. / when centromeres are separated
d. / when cytokinesis begins
____ 16. Which is the best description of the events that take place during anaphase II?
a. / The replicated chromosomes become visible.b. / Homologous chromosomes line up along the equator.
c. / Sister chromatids are separated and pulled to opposite sides of the cell.
d. / Homologous pairs are separated and pulled to opposite sides of the cell.
____ 17. A heterozygous organism is best described as which of these?
a. / dominant / c. / hybridb. / genotype / d. / true-breeding
____ 18. In which situation are the phenotypes of F2 offspring expected to follow the ratio of 9:3:3:1.
a. / a monohybrid cross for 2 unlinked traitsb. / a monohybrid cross for 2 closely linked traits
c. / a dihybrid cross for 2 unlinked traits
d. / a dihybrid cross for 2 closely linked traits
____ 19. Of the following species used in agriculture, which is most likely a polyploid?
a. / cow / c. / henb. / goat / d. / wheat
____ 20. A geneticist crossed fruit flies to determine whether two traits are linked. The geneticist crossed a fly with blistery wings and spineless bristles (bbss) with a heterozygous fly that had normal wings and normal bristles (BbSs). Which results in the next generation would suggest these traits are linked?
a. / 35 normal wings, normal bristles, 28 normal wings, spineless bristles, 23 blistery wings, normal bristles, 30 blistery wings, spineless bristlesb. / 105 normal wings, normal bristles, 101 normal wings, spineless bristles, 111 blistery wings, normal bristles, 115 blistery wings, spineless bristles
c. / 198 normal wings, normal bristles, 200 normal wings, spineless bristles, 185 blistery wings, normal bristles, 189 blistery wings, spineless bristles
d. / 222 normal wings, normal bristles, 27 normal wings, spineless bristles, 22 blistery wings, normal bristles, 228 blistery wings, spineless bristles
Figure 11-1
____ 21. Refer to Figure 11-1. If individual III-2 marries a person with the same genotype as individual I-1, what is the chance that one of their children will be afflicted with hemophilia?
a. / 0% / c. / 50%b. / 25% / d. / 75%
____ 22. What type of inheritance pattern does the trait represented by the shaded symbols in Figure 11-1 illustrate?
a. / incomplete dominance / c. / codominanceb. / multiple alleles / d. / sex-linked
____ 23. For the trait being followed in the pedigree, individuals II-1 and II-4 in Figure 11-1 can be classified as ____.
a. / homozygous dominant / c. / homozygous recessiveb. / mutants / d. / carriers
____ 24. What is the relationship between individual I-1 and individual III-2 in Figure 11-1?
a. / grandfather-granddaughter / c. / great aunt-nephewb. / grandmother-grandson / d. / mother-son
____ 25. If a female fruit fly heterozygous for red eyes (XRXr) crossed with a white-eyed male (XrY), what percent of their offspring would have white eyes?
a. / 0% / c. / 50%b. / 25% / d. / 75%
____ 26. When roan cattle are mated, 25% of the offspring are red, 50% are roan, and 25% are white. Upon examination, it can be seen that the coat of a roan cow consists of both red and white hairs. This trait is one controlled by ____.
a. / multiple alleles / c. / sex-linked genesb. / codominant alleles / d. / polygenic inheritance
____ 27. A cross between a white rooster and a black hen results in 100% blue Andalusian offspring. When two of these blue offspring are mated, the probable phenotypic ratio seen in their offspring would be ____.
a. / 100% blue / c. / 75% blue, 25% whiteb. / 75% black, 25% white / d. / 25% black, 50% blue, 25% white
Figure 11-2
____ 28. According to the pedigree in Figure 11-2, how many of the offspring in the III generation show the normal trait?
a. / 1 / c. / 4b. / 2 / d. / 5
____ 29. A phenotype that results from a dominant allele must have at least _____ dominant allele(s) present in the parent(s).
a. / one / c. / threeb. / two / d. / four
____ 30. Examine the graph in Figure 11-3, which illustrates the frequency in types of skin pigmentation in humans. Another human trait that would show a similar inheritance pattern and frequency of distribution is ____.
Figure 11-3
a. / height / c. / number of fingers and toesb. / blood type / d. / incidence of cystic fibrosis
____ 31. What phenotype is depicted in Figure 11-5?
Figure 11-5
a. / O / c. / Ab. / AB / d. / B
____ 32. Nondisjunction is related to a number of serious human disorders. How does nondisjunction cause these disorders?
a. / alters the number of gametes producedb. / alters the number of zygotes produced
c. / alters the chromosome structure
d. / alters the chromosome number
____ 33. A pea plant homozygous for the trait of smooth seeds is crossed with a pea plant that is homozygous for the trait of wrinkled seeds. The first generation produces seeds that are all smooth. What percent of the second-generation plants will have smooth seeds when the F1 generation is self-fertilized?
a. / 100% / c. / 50%b. / 75% / d. / 25%
Figure 11-6
This pedigree shows the transmission of a rare disease that is dehabilitating but not lethal. Carriers are not shown.
____ 34. Which type of heredity does the pedigree in Figure 11-6 demonstrate?
a. / autosomal recessive / c. / X-linked recessiveb. / autosomal dominant / d. / X-linked dominant
____ 35. What do galactosemia and Tay-Sachs disease have in common?
a. / Both are conditions in which the genotype will be seen in the phenotype.b. / Both are conditions characterized by respiratory failure.
c. / Both are conditions caused by the lack of a gene that codes for particular enzymes.
d. / Both are conditions caused by dominant alleles.
____ 36. The coat color in Labrador retrievers is controlled by two sets of alleles. The gene E/e determines whether the fur has pigment or not and is epistatically dominant to the gene B/b, which controls the darkness of pigment when it is there. A breeder crosses a purebred black Lab, with the genotype BBEE, and a purebred yellow Lab with the genotype bbee, producing offspring that are black. A test cross is done between these offspring and an individual with the genotype bbee. What is the expected ratio of black:chocolate:yellow?
a. / 1:1:2 / c. / 2:1:1b. / 1:2:1 / d. / 2:1:0
Figure 12-2
____ 37. Structure III in Figure 12-2 represents a(n) ____.
a. / gene / c. / codonb. / amino acid / d. / DNA molecule
____ 38. The process illustrated in Figure 12-2 is called ____.
a. / translation / c. / monoploidyb. / replication / d. / transcription
Help Wanted
Positions Available in the genetics industry. Hundreds of entry-level openings for tireless workers. No previous experience necessary. Must be able to transcribe code in a nuclear environment.
Accuracy and Speed vital for this job in the field of translation. Applicants must demonstrate skills in transporting and positioning amino acids. Salary commensurate with experience.
Executive Position available. Must be able to maintain genetic continuity through replication and control cellular activity by regulation of enzyme production. Limited number of openings. All benefits.
Supervisor of production of proteins—all shifts. Must be able to follow exact directions from double-stranded template. Travel from nucleus to the cytoplasm is additional job benefit.
Table 12-1
____ 39. Applicants for the third job of the Help Wanted ad in Table 12-1, "Executive Position," could qualify if they were ____.
a. / DNA / c. / tRNAb. / mRNA / d. / rRNA
Figure 12-3
____ 40. What type of mutation has occurred in Figure 12-3?
a. / substitution / c. / lethalb. / frameshift / d. / insertion
____ 41. What will be the result of the mutation in Figure 12-3?
a. / it will have no effect on protein functionb. / only one amino acid will change
c. / nearly every amino acid in the protein will be changed
d. / translation will not occur
____ 42. A DNA segment is changed from -AATTAGAAATAG- to -ATTAGAAATAG-. This is a ____.
a. / frameshift mutation / c. / inversionb. / insertion / d. / translation
____ 43. Where would a DNA substitution probably have the smallest or least effect on the organism?
a. / exon / c. / intronb. / histone / d. / operon
____ 44. A particular sequence of parent DNA has four purine bases and two pyrimidine bases. According to base-pairing rules, which of the following sequences could be formed during replication?
a. / two cytosine, two adenine, two thymineb. / two cytosine, two adenine, two uracil
c. / two adenine, two thymine, one guanine, one cytosine
d. / two adenine, two guanine, two cytosine
____ 45. Which of the following sequences of processes correctly reflects the central dogma?
a. / protein synthesis, transcription, translationb. / protein synthesis, translation, transcription
c. / transcription, translation, protein synthesis
d. / translation, transcription, protein synthesis
____ 46. You are a medical researcher trying to create a new antibiotic that will interfere with bacterial DNA replication without harming the eukaryotic host. You have found several chemicals that prevent DNA from unwinding and separating. Which of the following is the best chemical to use?
a. / a chemical that blocks uracil useb. / a chemical that cannot pass into the cell nucleus
c. / a chemical that is neutralized by cytoplasm
d. / a chemical that works only in the presence of histones
____ 47. This is a template DNA sequence: 3'AATCGC5'. This is a partially-completed mRNA strand transcribed from the DNA template: 3'GCGA5'. What is the next nucleotide that RNA polymerase will attach?
a. / A / c. / Tb. / C / d. / U
____ 48. Using DNA sequencing, you discover that a bacterium has experienced a deletion mutation that removed three nucleotides. The bacterium appears completely unaffected in all its functions. Where is the mostly likely location for the mutation?
a. / an exon / c. / a promoterb. / an intron / d. / a repressor
Table 12-2
____ 49. Three samples of DNA contain the percentages of nitrogenous bases listed in Table 12-2. According to Chargaff’s law, which two samples probably belong to the same species?
a. / 1 and 2b. / 1 and 3
c. / 2 and 3
d. / cannot tell without data on guanine and thymine
____ 50. The template strand of a piece of DNA being replicated reads: 5'-ATAGGCCGT-3'. A partially synthesized Okazaki fragment is 5'CCTA3'. If the next fragment is four bases long, what is its first base?
a. / A / c. / Gb. / C / d. / T
Completion
51. An individual with the genotype Aa is ______for the trait.
52. Genetic recombination occurs when chromosomes undergo ______.
53. Gregor Mendel is best known for his research on ______plants.
54. Aneupoidy, the condition of having an abnormal number of chromosomes, can occur during meiosis II, during which ______fail to separate.
55. ______, found at the end of chromosomes, prevent the chromosomes from fusing into rings.
56. A karyotype arranges chromosomes in the order of their number, which is also in ______order of size.
57. Analyzing the karyotype of a child before it is born has the benefit of alerting a mother to the presence of ______abnormalities.