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Chapter: 13 -Problem: 39 >> The wild-type sequence of part of a protein is NH2-Trp-Trp-Trp-Met-Arg-Glu-Trp-Thr-Met Each mutant in the following table differs from wildtype by a single point mutation. Using this information, determine the mRNA sequence coding for the wild-type polypeptide. If there is more than one possible nucleotide, list all possibilities.
Answer Preview: 5-UGG-UGG-…

, Chapter: 9 -Problem: 12 >> DNA was extracted from cells of Staphylococcus afermentans and analyzed for base composition. It was found that 37 percent of the bases are cytosine. With this information, is it possible to predict what percentage of the bases are adenine? If so, what percentage? If not, why not?
Answer Preview: Yes. Because DNA in bacteria is double-stranded, the 1…

, Chapter: 3 -Problem: 20 >> If four babies are born on a given day: (a) What is the chance that two will be boys and two will be girls? (b) What is the chance that all four will be girls? (c) What combination of boys and girls among four babies is most likely?(d) What is the chance that at least one baby will be a girl?
Answer Preview: (a) 4 (1/2) 2 (1/2) 2 = 4/16…

, Chapter: 14 -Problem: 13 >> Genomic clones of the chloroplastic glutamine synthetase gene (gln2) of maize are cleaved into two fragments by digestion with restriction endonuclease HindIII, whereas full-length maize gln2 cDNA clones are not cut by HindIII. Explain these results.
Answer Preview: The maize gln2 gene contains many introns, and one …

, Chapter: 18 -Problem: 30 >> Suppose that a woman carries an X chromosome in which the XIST locus has been deleted. The woman’s other X chromosome has an intact XIST locus. What pattern of X-inactivation would be observed throughout the woman’s body?
Answer Preview: The X chromosome containing the inta…

, Chapter: 13 -Problem: 40 >> Acridine dyes such as proflavin are known to induce primarily single base-pair additions and deletions. Suppose that the wild-type nucleotide sequence in the mRNA produced from a gene is 5?-AUGCCCUUUGGGAAAGGGUUUCCCUAA-3? Also, assume that a mutation is induced within this gene by proflavin, and, subsequently, a revertant of this mutation is similarly induced with proflavin and shown to result from
Answer Preview: 5-AUGC…

, Chapter: 5 -Problem: 17 >> Would a human with two X chromosomes and a Y chromosome be male or female?
Answer Preview: M…

, Chapter: 18 -Problem: 31 >> In Drosophila, the variegated phenotype of the white mottled allele is suppressed by a dominant autosomal mutation that knocks out the function of the gene for heterochromatin protein 1 (HP1), an important factor in heterochromatin formation. Flies with the white mottled allele and the suppressor mutation have an almost uniform red color in their eyes; without the suppressor mutation, the eyes are
Answer Preview: HP1, the protein encoded by the wild-type allele of the suppressor …

, Chapter: 8 -Problem: 10 >> (a) What are the genotypic differences between F- cells, F+ cells, and Hfr cells? (b) What are the phenotypic differences? (c) By what mechanism are F? cells converted into F+ cells? F+ cells to Hfr cells? Hfr cells to F+ cells?
Answer Preview: (a) F cells, no F factor present; F + cells, autonomous F factor; Hfr …

, Chapter: 9 -Problem: 7 >> (a) What background material did Watson and Crick have available for developing a model of DNA? (b) What was their contribution to building the model?
Answer Preview: (a) The ladder-like pattern was known from X-ray dif…

, Chapter: 3 -Problem: 2 >> Mendel crossed pea plants that produced round seeds with those that produced wrinkled seeds and self-fertilized the progeny. In the F2, he observed 5474 round seeds and 1850 wrinkled seeds. Using the letters W and w for the seed texture alleles, diagram Mendel’s crosses, showing the genotypes of the plants in each generation. Are the results consistent with the Principle of Segregation?
Answer Preview: Round (WW ) wrinkled (ww) F 1 round (Ww); F 1 self-fertilized F 2 3/4 round (2 WW; …

, Chapter: 7 -Problem: 24 >> Consider a female Drosophila with the following X chromosome genotype:The recessive alleles w and dor cause mutant eye colors (white and deep orange, respectively). However, w is epistatic over dor; that is, the genotypes w dor / Y and w dor/ w dor have white eyes. If there is 40 percent recombination between w and dor, what proportion of the sons from this heterozygous female will show a mutant p
Answer Preview: The female will produce four kinds of gamet…

, Chapter: 16 -Problem: 8 >> You have constructed a synthetic gene that encodes an enzyme that degrades the herbicide glyphosate. You wish to introduce your synthetic gene into Arabidopsis plants and test the transgenic plants for resistance to glyphosate. How could you produce a transgenic Arabidopsis plant harboring your synthetic gene by A. tumefaciensmediated transformation?
Answer Preview: You would first construct a chimeric gene containing your synthetic gene fused to a plant pro…

, Chapter: 14 -Problem: 11 >> Compare the nucleotide-pair sequences of genomic DNA clones and cDNA clones of specific genes of higher plants and animals. What is the most frequent difference that you would observe?
Answer Preview: Most genes of higher plants and animals contain non-coding intr…

, Chapter: 18 -Problem: 26 >> Epigenetic states are transmitted clonally through cell division. What kinds of observations indicate that these states can be reversed or reset?
Answer Preview: Here are two observations that show reversal or resetting of …

, Chapter: 13 -Problem: 38 >> Which of the following amino acid substitutions should you expect to be induced by 5-bromouracil with the highest frequency? (a) Met ? Leu; (b) Met ? Thr; (c) Lys ? Thr; (d) Lys ? Gln; (e) Pro ? Arg; or (f) Pro ? Gln? Why?
Answer Preview: (b) Met Thr. 5-Bromoura…

, Chapter: 9 -Problem: 20 >> A diploid nucleus of Drosophila melanogaster contains about 3.4 × 108 nucleotide pairs. Assume (1) that all nuclear DNA is packaged in nucleosomes and (2) that an average internucleosome linker size is 60 nucleotide pairs. How many nucleosomes would be present in a diploid nucleus of D. melanogaster? How many molecules of histone H2a, H2b, H3, and H4 would be required?
Answer Preview: In the diploid nucleus of D. mel…

, Chapter: 16 -Problem: 10 >> A group of bodies are found buried in a forest. The police suspect that they may include the missing Jones family (two parents and two children). They extract DNA from bones and examine (using PCR) genes A and B, which are known to contain tandem triplet repeats of variable length. They also analyze DNA from two other men. The results are shown below where the numbers indicate the number of copies
Answer Preview: The woman could be the mother of both chi…

, Chapter: 8 -Problem: 22 >> Mutations nrd 11 (gene nrd B, encoding the beta subunit of the enzyme ribonucleotide reductase), am M69 (gene 63, encoding a protein that aids tail-fiber attachment), and nd 28 (gene denA, encoding the enzyme endonuclease II) are known to be located between gene 31 and gene 32 on the bacteriophage T4 chromosome. Mutations am N54 and am A453 are located in genes 31 and 32, respectively. Given the t
Answer Preview: amA453 …

, Chapter: 4 -Problem: 13 >> The dominant mutation Plum in the fruit fly also causes brownish-purple eyes. Is it possible to determine by genetic experiments whether Plum is an allele of the brown or purple genes?
Answer Preview: No. The test f…

, Chapter: 3 -Problem: 1 >> On the basis of Mendel’s observations, predict the results from the following crosses with peas: (a) A tall (dominant and homozygous) variety crossed with a dwarf variety; (b) The progeny of (a) self-fertilized; (c) The progeny from (a) crossed with the original tall parent; (d) The progeny of (a) crossed with the original dwarf parent.
Answer Preview: (a) All tall; (b) …

, Chapter: 15 -Problem: 5 >> As part of the Human Genome Mapping Project, you are trying to clone a gene involved in colon cancer. Your first step is to localize the gene using RFLP markers. In the following table, RFLP loci are defined by STS number (e.g., STS1), and the gene for colon cancer is designated C. (a) Given the percentage recombination between different RFLP loci and the gene for colon cancer shown in the table,
Answer Preview: (a) (b) 3 3 10 9 bp/3 3 10 3 cM = 1 10 6 bp/cM. The tot…

, Chapter: 10 -Problem: 23 >> In E. coli, three different proteins are required to unwind the parental double helix and keep the unwound strands in an extended template form. What are these proteins, and what are their respective functions?
Answer Preview: DNA helicase unwinds the DNA double helix, and single- strand DNA-binding protei…

, Chapter: 3 -Problem: 24 >> In the following pedigrees, determine whether the trait is more likely to be due to a dominant or a recessive allele. Assume the trait is rare in the population.a.b. Transcribed Image Text: IV 5 8. IV
Answer Preview: (a) Re…

, Chapter: 13 -Problem: 36 >> Keeping in mind the known nature of the genetic code, the information given about phage MS2 in Problem 13.32, and the information you have learned about nitrous acid in Problem 13.35, would you expect nitrous acid to induce any mutations that would result in amino acid substitutions of the type glycine ? another amino acid if the mutagenesis were carried out on a suspension of mature (nonreplicati
Answer Preview: No. The glycine codon is GGX, where X can be any one of the four bases. Because …

, Chapter: 16 -Problem: 30 >> The Streptococcus pyogenes Cas9 endonuclease can be targeted to a specific genomic DNA sequence by an sgRNA that at its 5? end has 20 nucleotides complementary to the target sequence. If this target sequence is immediately upstream of the protospacer adjacent motif (PAM) 5?NGG-3?, Cas9 will cleave the target DNA. Suppose you have chosen a 20-nucleotide target sequence in the genome of Drosophila m
Answer Preview: You could use the 20-nucleotide sequence as a query in BLAST to scan the sequenced …

, Chapter: 18 -Problem: 13 >> Suppose that the segment of the hsp70 gene that was used to make the hsp70/gfp fusion in the preceding problem had mutations in each of its heat-shock response elements. Would the green fluorescent protein encoded by this fusion gene be synthesized in genetically transformed flies?
Answer Preview: Probably not unless the promoter …

, Chapter: 15 -Problem: 17 >> A contig map of one segment of chromosome 3 of Arabidopsis is as follows. (a) If an EST hybridizes with genomic clones C, D, and E, but not with the other clones, in which segment of chromosome 3 is the EST located? (b) If a clone of gene ARA hybridizes only with genomic clones C and D, in which chromosome segment is the gene located? (c) If a restriction fragment hybridizes with only one of the g
Answer Preview: (a) Segmen…

, Chapter: 4 -Problem: 25 >> In a species of tree, seed color is determined by four independently assorting genes: A, B, C, and D. The recessive alleles of each of these genes (a, b, c, and d) produce abnormal enzymes that cannot catalyze a reaction in the biosynthetic pathway for seed pigment. This pathway is diagrammed as follows:When both red and blue pigments are present, the seeds are purple. Trees with the genotypes Aa
Answer Preview: (a) Purple red; (b) proportion white (aa) = 1…

, Chapter: 2 -Problem: 8 >> In what way do the microtubule organizing centers of plant and animal cells differ?
Answer Preview: The microtubule organizing c…

, Chapter: 14 -Problem: 4 >> In what ways do restriction endonucleases differ from other endonucleases?
Answer Preview: Restriction endonucleases recogni…

, Chapter: 4 -Problem: 2 >> In rabbits, coloration of the fur depends on alleles of the gene c. From information given in the chapter, what phenotypes and proportions would be expected from the following crosses: (a) c+c+ × cc; (b) c+c × c+c; (c) c+c b × c+c cb; (d) cc cb × cc; (e) c+c b × c+c; (f) c bc × cc?
Answer Preview: (a) All wild-type; (b) 3/4 wild-type, …

, Chapter: 18 -Problem: 15 >> A particular transcription factor binds to enhancers in 40 different genes. Predict the phenotype of individuals homozygous for a frameshift mutation in the coding sequence of the gene that specifies this transcription factor.
Answer Preview: The mutation is likely to be lethal in homozygou…

, Chapter: 15 -Problem: 22 >> Of the cereal grass species, only maize contains two copies of each block of linked genes. What does this duplication of sets of maize genes indicate about the origin of this agronomically important species?
Answer Preview: The presence of two copies of each block of genes in the corn genome indicate…

, Chapter: 17 -Problem: 3 >> In the lactose operon of E. coli, what is the function of each of the following genes or sites:(a) Regulator, (b) Operator, (c) Promoter, (d) Structural gene Z, and (e) Structural gene Y?
Answer Preview: Gene or Regulatory Element Function (a) Regulator gene Encodes the r…

, Chapter: 16 -Problem: 15 >> The generation of transgenic plants using A. tumefaciensmediated transformation often results in multiple sites of insertion. These sites frequently vary in the level of transgene expression. What approaches could you use to determine whether or not transgenic plants carry more than one transgene and, if so, where the transgenes are inserted into chromosomes?
Answer Preview: Probing Southern blots of restriction enzyme-digested DNA of the transgenic plan…

, Chapter: 6 -Problem: 24 >> Each of six populations of Drosophila in different geographic regions had a specific arrangement of bands in one of the large autosomes: (a) 12345678 (b) 12263478 (c) 15432678 (d) 14322678 (e) 16223478 Assume that arrangement (a) is the original one. In what order did the other arrangements most likely arise, and what type of chromosomal aberration is responsible for each change?
Answer Preview: Arrangement (a) Produced (c) By inversion of segm…

, Chapter: 4 -Problem: 9 >> A woman who has blood type O and blood type M marries a man who has blood type AB and blood type MN. If we assume that the genes for the A-B-O and M-N bloodtyping systems assort independently, what blood types might the children of this couple have, and in what proportions?
Answer Preview: The woman is ii LMLM; the man …

, Chapter: 18 -Problem: 27 >> A researcher hypothesizes that in mice gene A is actively transcribed in liver cells, whereas gene B is actively transcribed in brain cells. Describe procedures that would allow the researcher to test this hypothesis.
Answer Preview: RNA could be isolated from liver and brain tissue. Northern blotting or RT-PCR wi…

, Chapter: 8 -Problem: 15 >> What does the term cotransduction mean? How can cotransduction frequencies be used to map genetic markers?
Answer Preview: Cotransduction refers to the simultaneous transduction of …

, Chapter: 4 -Problem: 12 >> In the fruit fly, recessive mutations in either of two independently assorting genes, brown and purple, prevent the synthesis of red pigment in the eyes. Thus, homozygotes for either of these mutations have brownish-purple eyes.However, heterozygotes for both of these mutations have dark red, that is, wild-type eyes. If such double heterozygotes are intercrossed, what kinds of progeny will be prod
Answer Preview: 9/16 da…

, Chapter: 2 -Problem: 6 >> With a focus on the chromosomes, what are the key events during interphase and M phase in the eukaryotic cell cycle?
Answer Preview: During interphase, the chromosomes duplicate. During M phase (mitosis), the duplicated c…

, Chapter: 15 -Problem: 18 >> Eight human€“Chinese hamster radiation hybrids were tested for the presence of six human ESTs designated A through F. The results are shown in the following table, where a plus indicates that a marker was present and a minus indicates that it was absent. Based on these data, do any of the ESTs appear to be closely linked? Which ones? What would be needed for you to be more certain of your answer?
Answer Preview: EST markers D and E appear to be closely linked. The …

, Chapter: 6 -Problem: 3 >> During meiosis, why do some tetraploids behave more regularly than triploids?
Answer Preview: In allotetraploids, each member of the different sets of chromos…

, Chapter: 16 -Problem: 31 >> How could the CRISPR/Cas9 system be used to create a translocation between two autosomes in cultured human cells?
Answer Preview: Create two sgRNAs, one to target a sequence on a particular autosome and the other to …

, Chapter: 11 -Problem: 16 >> A segment of DNA in E. coli has the following sequence of nucleotide pairs: When this segment of DNA is transcribed by RNA polymerase, what will be the sequence of nucleotides in the RNA transcript if the promoter is located to the left of the sequence shown? Transcribed Image Text: 3'-A TGCTACTGCTA
Answer Preview: If there is a promoter located upstream from thi…

, Chapter: 23 -Problem: 10 >> A mutation in the rascellular oncogene can cause cancer when it is in heterozygous condition, but a mutation in the RBtumor suppressor gene can cause cancer only when it is in homozygous condition. What does this difference between dominant and recessive mutations imply about the roles that the rasand RBgene products play in normal cellular activities?
Answer Preview: Ras protein is an a…

, Chapter: 3 -Problem: 10 >> A researcher studied six independently assorting genes in a plant. Each gene has a dominant and a recessive allele: R black stem, r red stem; D tall plant, d dwarf plant; C full pods, c constricted pods; O round fruit, o oval fruit; H hairless leaves, h hairy leaves; W purple flower, w white flower. From the cross (P1) Rr Dd cc Oo Hh Ww × (P2) Rr dd Cc oo Hh ww, (a) How many kinds of gametes can b
Answer Preview: (a) 2 2 1 2 2 2 = 32; (b) 3 2 2 2 3 2 = …

, Chapter: 13 -Problem: 27 >> How does the action and mutagenic effect of 5-bromouracil differ from that of nitrous acid?
Answer Preview: Nitrous acid acts as a mutagen on either replicating or nonreplicating DNA a…

, Chapter: 5 -Problem: 23 >> Males in a certain species of deer have two nonhomologous X chromosomes, denoted X1 and X2, and a Y chromosome. Each X chromosome is about half as large as the Y chromosome, and its centromere is located near one of the ends; the centromere of the Y chromosome is located in the middle. Females in this species have two copies of each of the X chromosomes and lack a Y chromosome. How would you predi
Answer Preview: Since the centromere is at the end of each small X chromoso…

, Chapter: 3 -Problem: 4 >> A woman has a rare abnormality of the eyelids called ptosis, which prevents her from opening her eyes completely. This condition is caused by a dominant allele, P. The woman’s father had ptosis, but her mother had normal eyelids. Her father’s mother had normal eyelids. (a) What are the genotypes of the woman, her father, and her mother? (b) What proportion of the woman’s children will have ptosis
Answer Preview: (a) Womans ge…

, Chapter: 8 -Problem: 20 >> Two additional mutations in the trp A gene of E. coli, trp A58 and trp A487, were ordered relative to trp A223 and the outside marker anth by three-factor transduction crosses as described in Problem 8.18. The results of these crosses are summarized in the following table. What is the linear order of anth and the three mutant sites in the trp A gene?
Answer Preview: anth …

, Chapter: 10 -Problem: 5 >> How might continuous and discontinuous modes of DNA replication be distinguished experimentally?
Answer Preview: If nascent DNA is labeled by exposure to 3H-thymidine for very short per…

, Chapter: 2 -Problem: 9 >> Match the stages of mitosis with the events they encompass: Stages: (1) Anaphase, (2) Metaphase, (3) Prophase, (4) Telophase. Events: (a) Reformation of the nucleolus,(b) Disappearance of the nuclear membrane,(c) Condensation of the chromosomes, (d) Formation of the mitotic spindle, (e) Movement of chromosomes to the equatorial plane, (f) Movement of chromosomes to the poles, (g) Decondensation of
Answer Preview: (1) Anaphase: (f), (…

, Chapter: 14 -Problem: 6 >> What determines the sites at which DNA molecules will be cleaved by a restriction endonuclease?
Answer Preview: The nucleotide-pair sequence. Restriction endonucleases recognize a specific nucleo…

, Chapter: 9 -Problem: 16 >> Compare and contrast the structures of the A, B, and Z forms of DNA.
Answer Preview: The B form of DNA helix is that proposed by Watson and Crick and is the …

, Chapter: 18 -Problem: 18 >> In Drosophila, expression of the yellow gene is needed for the formation of dark pigment in many different tissues; without this expression, a tissue appears yellow in color. In the wings, the expression of the yellow gene is controlled by an enhancer located upstream of the gene’s transcription initiation site. In the tarsal claws, expression is controlled by an enhancer located within the gene’s
Answer Preview: Yes. Enhancers a…

, Chapter: 14 -Problem: 2 >> Listed in this question are four different single strands of DNA. Which of these, in their double-stranded form, would you expect to be cleaved by a restriction endonuclease?(a) ACTCCAGAATTCACTCCG (b) GCCTCATTCGAAGCCTGA (c) CTCGCCAATTGACTCGTC (d) ACTCCACTCCCGACTCCA
Answer Preview: Restriction endonucleases cleave at palindromes in double-stranded DNA. A palindrome (indicated …

, Chapter: 4 -Problem: 5 >> From information in the chapter about the ABO blood types, what phenotypes and ratios are expected from the following matings: (a) IA IA × IB IB; (b) IA IB × ii; (c) IA i × IB i; and (d) IA i × ii;
Answer Preview: (a) All AB; (b…

, Chapter: 16 -Problem: 6 >> In humans, the absence of an enzyme called purine nucleoside phosphorylase (PNP) results in a severe T-cell immunodeficiency similar to that of severe combined immunodeficiency disease (SCID). PNP deficiency exhibits an autosomal recessive pattern of inheritance, and the gene encoding human PNP has been cloned and sequenced. Would PNP deficiency be a good candidate for treatment by gene therapy? D
Answer Preview: Yes. A somatic-cell gene therapy procedure similar to that used for X-linked SCID might …

, Chapter: 11 -Problem: 19 >> A segment of human DNA has the following sequence of nucleotide pairs:When this segment of DNA is transcribed by RNA polymerase, what will be the sequence of nucleotides in the RNA transcript? Transcribed Image Text: 3'ATATTTACGIGCTACCITGCTGATAGGAC T- |||||||||||||||| | || |||| ||||| || 5-TÀTÀÀ Á???
Answer Preview: Assuming that there is a CAAT box l…

, Chapter: 10 -Problem: 1 >> DNA polymerase I of E. coli is a single polypeptide of molecular weight 103,000.(a) What enzymatic activities other than polymerase activity does this polypeptide possess? (b) What are the in vivo functions of these activities? (c) Are these activities of major importance to an E. coli cell? Why?
Answer Preview: (a) Both 3 5 and 5 3 exonuclease activities. (b) The 3 5 exonuclease proofreads the nas…

, Chapter: 16 -Problem: 23 >> How can RNAi gene silencing be used to determine the function of genes?
Answer Preview: RNAi involves the use of double-stranded RNAs, where …

, Chapter: 8 -Problem: 18 >> The data in the following table were obtained from three-point transduction tests made to determine the order of mutant sites in the A gene encoding the a subunit of tryptophan synthetase in E. coli. Anth is a linked, unselected marker. In each cross, trp+recombinants were selected and then scored for the anth marker (anth+or anth-). What is the linear order of anth and the three mutant alleles of
Answer Preview: anth…

, Chapter: 16 -Problem: 12 >> The DNA profiles shown in this problem were prepared using genomic DNA from blood cells obtained from a woman, her daughter, and three men who all claim to be the girl€™s father. Based on the DNA profiles, what can be determined about paternity in this case? Transcribed Image Text: ? ? FI F2 F3 ??
Answer Preview: Neither F1 nor F2 co…

, Chapter: 7 -Problem: 31 >> The following pedigree, described in 1937 by C. L. Birch, shows the inheritance of X-linked color blindness and hemophilia in a family. What is the genotype of II-2? Do any of her children provide evidence for recombination between the genes for color blindness and hemophilia? Transcribed Image Text:
Answer Preview: II-1 has the genotype C h/c H, that i…

, Chapter: 9 -Problem: 26 >> Are the scaffolds of eukaryotic chromosomes composed of histone or nonhistone chromosomal proteins? How has this been determined experimentally?
Answer Preview: Nonhistone chromosomal proteins. The …

, Chapter: 2 -Problem: 17 >> From the information given in Table 2.1 in this chapter, is there a relationship between genome size (measured in base pairs of DNA) and gene number? Explain.
Answer Preview: Among eukaryotes, there does not seem to be a clear relationship between genome size and g…

, Chapter: 11 -Problem: 15 >> A particular gene is inserted into the phage lambda chromosome and is shown to contain three introns.(a) The primary transcript of this gene is purified from isolated nuclei. When this primary transcript is hybridized under R-loop conditions with the recombinant lambda chromosome carrying the gene, what will the R-loop structure(s) look like? Label your diagram. (b) The mRNA produced from the prim
Answer Preview: Displaced single-stranded DNA ("R-Hoop") Primar…

, Chapter: 6 -Problem: 17 >> One chromosome in a plant has the sequence A B C D E F, and another has the sequence M N O P Q R. A reciprocal translocation between these chromosomes produced the following arrangement: A B C P Q R on one chromosome and M N O D E F on the other. Illustrate how these translocated chromosomes would pair with their normal counterparts in a heterozygous individual during meiosis.
Answer Preview: A B …

, Chapter: 3 -Problem: 5 >> In pigeons, a dominant allele C causes a checkered pattern in the feathers; its recessive allele c produces a plain pattern. Feather coloration is controlled by an independently assorting gene; the dominant allele B produces red feathers, and the recessive allele b produces brown feathers. Birds from a true-breeding checkered, red variety are crossed to birds from a true-breeding plain, brown vari
Answer Preview: (a) Checkered, red (CC BB) plain, brown (c…

, Chapter: 13 -Problem: 24 >> How does nitrous acid induce mutations? What specific end results might be expected in DNA and mRNA from the treatment of viruses with nitrous acid?
Answer Preview: Nitrous acid brings about a substitution of an OH group for an NH …

, Chapter: 23 -Problem: 14 >> The following pedigree shows the inheritance of familial ovarian cancer caused by a mutation in the BRCA1gene. Should II-1 be tested for the presence of the predispos-ing mutation? Discuss the advantages and disadvantages of testing. Transcribed Image Text: Ovarian cancer O Normal
Answer Preview: II-1 should be tested for the BRCA1mutation that appar-ently was involved in the ovarian …

, Chapter: 18 -Problem: 9 >> What techniques could be used to show that a plant gene is transcribed when the plant is illuminated with light?
Answer Preview: Northern blotting of RNA extrac…

, Chapter: 11 -Problem: 14 >> What is the function of the introns in eukaryotic genes?
Answer Preview: This is a wide-open question at present! There is much speculation, but little hard evidence. …

, Chapter: 7 -Problem: 5 >> Genes on different chromosomes recombine with a frequency of 50 percent. Is it possible for two genes on the same chromosome to recombine with this frequency?
Answer Preview: Yes, i…

, Chapter: 3 -Problem: 26 >> Peas heterozygous for three independently assorting genes were intercrossed. (a) What proportion of the offspring will be homozygous for all three recessive alleles? (b) What proportion of the offspring will be homozygous for all three genes? (c) What proportion of the offspring will be homozygous for one gene and heterozygous for the other two? (d) What proportion of the offspring will be homozyg
Answer Preview: (a) (1/4) 3 = 1/64; (b) (1/2) 3 = 1/…

, Chapter: 8 -Problem: 12 >> What are the basic differences between generalized transduction and specialized transduction?
Answer Preview: Generalized transduction: (1) Transducing particles often contain only host DNA; …

, Chapter: 9 -Problem: 5 >> (a) What was the objective of the experiment carried out by Hershey and Chase? (b) How was the objective accomplished? (c) What is the significance of this experiment?
Answer Preview: (a) The objective was to determine whether the genetic material was DNA or protein. …

, Chapter: 18 -Problem: 23 >> Would double-stranded RNA derived from an intron be able to induce RNA interference?
Answer Preview: Short interfering RNAs target messenger R…

, Chapter: 13 -Problem: 37 >> Would you expect nitrous acid to induce a higher frequency of Tyr ? Ser or Tyr ? Cys substitutions? Why?
Answer Preview: Tyr Cys substitutions; Tyr to Cys requ…

, Chapter: 23 -Problem: 7 >> When cellular oncogenes are isolated from different animals and compared, the amino acid sequences of the polypeptides they encode are found to be very similar. What does this suggest about the functions of these polypeptides?
Answer Preview: The products …

, Chapter: 18 -Problem: 29 >> Why do null mutations in the msl gene in Drosophila have no effect in females?
Answer Preview: The msl …

, Chapter: 13 -Problem: 33 >> Would the different amino acid substitutions induced by 5-bromouracil at position 112 of the coat polypeptide that you indicated in Problem 13.32 be expected to occur with equal frequency? If so, why? If not, why not?Which one(s), if any, would occur more frequently?
Answer Preview: No. Leucine proline would occur more frequently. …

, Chapter: 23 -Problem: 15 >> In what sense is pRB a negative regulator of E2F tran-scription factors?
Answer Preview: By binding to E2F transcription factors, pRB prevents t…

, Chapter: 3 -Problem: 9 >> How many different kinds of F1 gametes, F2 genotypes, and F2 phenotypes would be expected from the following crosses: (a) AA × aa; (b) AA BB × aa bb; (c) AA BB CC × aa bb cc? (d) What general formulas are suggested by these answers?
Answer Preview: F1 Gametes F2 Genotypes F2 Phenotypes (a) 2 3 2 (b) 2 2 = 4 3 3 = 9 2 2 = …

, Chapter: 10 -Problem: 28 >> Two mutant strains of E. coli each have a temperature sensitive mutation in a gene that encodes a product required for chromosome duplication. Both strains replicate their DNA and divide normally at 25°C but are unable to replicate their DNA or divide at 42°C. When cells of one strain are shifted from growth at 25°C to growth at 42°C, DNA synthesis stops immediately. When cells of the other strain
Answer Preview: The product of the first gene i…

, Chapter: 6 -Problem: 26 >> A male mouse that is heterozygous for a reciprocal translocation between the X chromosome and an autosome is crossed to a female mouse with a normal karyotype. The autosome involved in the translocation carries a gene responsible for coloration of the fur. The allele on the male’s translocated autosome is wild-type, and the allele on its nontranslocated autosome is mutant; however, because the wil
Answer Preview: The phenotype in the female offspring is mosaic because one of the X chromosomes is inactiv…

, Chapter: 3 -Problem: 29 >> A researcher who has been studying albinism has identified a large group of families with four children in which at least one child shows albinism. None of the parents in this group of families shows albinism. Among the children, the ratio of those without albinism to those with albinism is 1.7:1. The researcher is surprised by this result because he thought that a 3:1 ratio would be expected on t
Answer Preview: The researcher has obtained what appears to be a non- Mendelian ratio because he has been studying only families in which at least one child shows alb…

, Chapter: 15 -Problem: 11 >> What has this analysis revealed? What are the genotypes of the three different types of DNA samples?
Answer Preview: The results of this analysis reveal that the EcoRI cleavage site within the o…

, Chapter: 9 -Problem: 9 >> (a) If a virus particle contained double-stranded DNA with 200,000 base pairs, how many nucleotides would be present? (b) How many complete spirals would occur on each strand? (c) How many atoms of phosphorus would be present? (d) What would be the length of the DNA configuration in the virus?
Answer Preview: (a) 400,00…

, Chapter: 3 -Problem: 12 >> Mendel testcrossed pea plants grown from yellow, round F1 seeds to plants grown from green, wrinkled seeds and obtained the following results: 31 yellow, round; 26 green, round; 27 yellow, wrinkled; and 26 green, wrinkled. Are these results consistent with the hypothesis that seed color and seed texture are controlled by independently assorting genes, each segregating two alleles?
Answer Preview: On the hypothesis, the expected number in each class is 27 5; 2 with thre…

, Chapter: 11 -Problem: 17 >> A segment of DNA in E. coli has the following sequence of nucleotide pairs: When this segment of DNA is transcribed by RNA polymerase, what will be the sequence of nucleotides in the RNA transcript? Transcribed Image Text: 3'A TATTACTGCAATGGGCTGTATCG- III!!||!!|||I|||||!||||II 5'-TATAATGÅ???TÀ????Å?
Answer Preview: Assuming that there is a 35 sequence upst…

, Chapter: 9 -Problem: 8 >> (a) Why did Watson and Crick choose a double helix for their model of DNA structure? (b) Why were hydrogen bonds placed in the model to connect the bases?
Answer Preview: (a) A multistranded, spiral structure was suggested by the X-ray diffracti…

, Chapter: 16 -Problem: 9 >> A human STR locus contains a tandem repeat (TAGA)n, where n may be any number between 5 and 15. How many alleles of this locus would you expect to find in the human population?
Answer Preview: Eleven, rangi…

, Chapter: 15 -Problem: 23 >> Five human genomic DNA clones present in PAC vectors were tested by hybridization for the presence of six sequence-tagged sites designated STS1 through STS6. The results are given in the following table: a plus indicates the presence of the STS, and a minus indicates the absence of the STS. (a) What is the order of the STS sites on the chromosome?(b) Draw the contig map defined by these data.
Answer Preview: (a) Order of STS …

, Chapter: 9 -Problem: 11 >> RNA was extracted from TMV (tobacco mosaic virus) particles and found to contain 20 percent cytosine (20 percent of the bases were cytosine). With this information, is it possible to predict what percentage of the bases in TMV are adenine? If so, what percentage? If not, why not?
Answer Preview: No. TMV RNA is si…

, Chapter: 18 -Problem: 14 >> The polypeptide products of two different genes, A and B, each function as transcription factors. These polypeptides interact to form dimers: AA homodimers, BB homodimers, and AB heterodimers. If the A and B polypeptides are equally abundant in cells, and if dimer formation is random, what is the expected ratio of homodimers to heterodimers in these cells?
Answer Preview: With equal abundance of the A and B polypeptides, AA homodime…

, Chapter: 7 -Problem: 28 >> In the following testcross, genes a and b are 20 cM apart, and genes b and c are 10 cM apart: a + c / + b + × a b c / a b c. If the coefficient of coincidence is 0.5 over this interval on the linkage map, how many triply homozygous recessive individuals are expected among 1000 progeny?
Answer Preview: …

, Chapter: 16 -Problem: 4 >> How might the characterization of the CF gene and its product lead to the treatment of cystic fibrosis by somatic-cell gene therapy? What obstacles must be overcome before cystic fibrosis can be treated successfully by gene therapy?
Answer Preview: Once the function of the CF gene product has been established, scientists should be able to develop …

, Chapter: 15 -Problem: 9 >> VNTRs and STRs are specific classes of polymorphisms. What is the difference between a VNTR and an STR?
Answer Preview: Variable number tandem repeats (VNTRs) …

, Chapter: 6 -Problem: 14 >> In a Drosophila salivary chromosome, the bands have a sequence of 1 2 3 4 5 6 7 8. The homologue with which this chromosome is synapsed has a sequence of 1 2 3 6 5 4 7 8. What kind of chromosome change has occurred?Draw the synapsed chromosomes.
Answer Preview: The animal is h…

, Chapter: 3 -Problem: 27 >> The following pedigree shows the inheritance of a recessive trait. What is the chance that the couple III-3 and III-4 will have an affected child? Transcribed Image Text: II
Answer Preview: …

, Chapter: 14 -Problem: 12 >> Most of the genes of plants and animals that were cloned soon after the development of recombinant DNA technologies were genes encoding products that are synthesized in large quantities in specialized cells. For example, about 90 percent of the protein synthesized in mature red blood cells of mammals consists of ?- and b-globin chains, and the globin genes were among the first mammalian genes clon
Answer Preview: Higher eukaryotes have very large genomes; for example, the genomes of mammals contain …

, Chapter: 9 -Problem: 3 >> How could it be demonstrated that the mixing of heatkilled Type III pneumococcus with live Type II resulted in a transfer of genetic material from Type III to Type II rather than a restoration of viability to Type III by Type II?
Answer Preview: Purified DNA from Type III c…

, Chapter: 2 -Problem: 19 >> A cell of the bacterium Escherichia coli, a prokaryote, contains one chromosome with about 4.6 million base pairs of DNA comprising 4288 protein-encoding genes. A cell of the yeast Saccharomyces cerevisiae, a eukaryote, contains about 12 million base pairs of DNA comprising 6268 genes, and this DNA is distributed over 16 distinct chromosomes. Are you surprised that the chromosome of a prokaryote i
Answer Preview: It is a bit surprising that yeast chromosomes are, on average, s…

, Chapter: 15 -Problem: 6 >> What are STRs? Why are they sometimes called microsatellites?
Answer Preview: STRs are polymorphic tandem repeats of sequen…

, Chapter: 9 -Problem: 13 >> If one strand of DNA in the Watson–Crick double helixhas a base sequence of 5-GTCATGAC-3, what is the base sequence of the complementary strand?
Answer Preview: 3-C…

, Chapter: 17 -Problem: 23 >> What do trp attenuation and the lysine riboswitch have in common?
Answer Preview: Both trp attenuation and the lysine riboswitch turn off gene expression by t…

, Chapter: 8 -Problem: 8 >> A nutritionally defective E. coli strain grows only on a medium containing thymine, whereas another nutritionally defective strain grows only on a medium containing leucine. When these two strains were grown together, a few progeny were able to grow on a minimal medium with neither thymine nor leucine. How can this result be explained?
Answer Preview: There are two possible explanations. One possibility is that a sponta…

, Chapter: 5 -Problem: 14 >> In Drosophila, a recessive mutation called chocolate (c) causes the eyes to be darkly pigmented. The mutant phenotype is indistinguishable from that of an autosomal recessive mutation called brown (bw). A cross of chocolate- eyed females to homozygous brown males yielded wild-type F1 females and darkly pigmented F1 males. If the F1 flies are intercrossed, what types of progeny are expected, and in
Answer Preview: 3/8 wild-type …

, Chapter: 18 -Problem: 5 >> In the polytene chromosomes of Drosophila larvae (Chapter 6), some bands form large “puffs” when the larvae are subjected to high temperatures. How could you show that these puffs contain genes that are vigorously transcribed in response to this heat shock treatment?
Answer Preview: One procedure would be to provide larvae with radioactively labeled UTP, …

, Chapter: 13 -Problem: 43 >> In Drosophila, white, white cherry, and vermilion are all sexlinked mutations affecting eye color. All three mutations are recessive to their wild-type allele(s) for red eyes. A white-eyed female crossed with a vermilion-eyed male produces white-eyed male offspring and red-eyed (wildtype) female offspring. A white-eyed female crossed with a white cherry-eyed male produces white-eyed sons and light
Answer Preview: The complementation test for allelism involves placing mutations pairwise in a common protoplasm in …

, Chapter: 10 -Problem: 7 >> The Boston barberry is an imaginary plant with a diploid chromosome number of 4, and Boston barberry cells are easily grown in suspended cell cultures. 3H-thymidine was added to the culture medium in which a G1-stage cell of this plant was growing. After one cell ONLINE_generation of growth in 3H-thymidine-ontaining medium, colchicine was added to the culture medium. The medium now contained both
Answer Preview: Two Plus tw…

, Chapter: 16 -Problem: 25 >> Insertional mutagenesis is a powerful tool in both plants and animals. However, when performing large-scale insertional mutagenesis, what major advantage do plants have over animals?
Answer Preview: Plants have an advantage over anima…

, Chapter: 15 -Problem: 12 >> Both an RFLP and a mutation that causes deafness in humans map to the same location on the same chromosome. How can you determine whether or not the RFLP overlaps with the gene containing the deafness mutation?
Answer Preview: You can start a chromosome walk using the hybridization p…

, Chapter: 6 -Problem: 29 >> Cytological examination of the sex chromosomes in a man has revealed that he carries an insertional translocation. A small segment has been deleted from the Y chromosome and inserted into the short arm of the X chromosome; this segment contains the gene responsible for male differentiation (SRY). If this man marries a karyotypically normal woman, what types of progeny will the couple produce?
Answer Preview: XX zygotes will develop into males because o…

, Chapter: 3 -Problem: 6 >> In mice, the allele C for colored fur is dominant over the allele c for white fur, and the allele V for normal behavior is dominant over the allele v for waltzing behavior, a form of dis-coordination. Given the genotypes of the parents in each of the following crosses: (a) Colored, normal mice mated with white, normal mice produced 29 colored, normal, and 10 colored, waltzing progeny (b) Colored,
Answer Preview: (a) Colored, normal (CC Vv) whit…

, Chapter: 8 -Problem: 7 >> You have identified three mutations—a, b, and c—in Streptococcus pneumoniae. All three are recessive to their wild-type alleles a+, b+, and c+. You prepare DNA from a wild-type donor strain and use it to transform a strain with genotype a b c. You observe a+b+ transformants and a+c+ transformants, but no b+c+ transformants. Are these mutations closely linked? If so, what is their order on the Stre
Answer Preview: The a, b, and c mu…

, Chapter: 2 -Problem: 21 >> In flowering plants, two nuclei from the pollen grain participate in the events of fertilization. With which nuclei from the female gametophyte do these nuclei combine? What tissues are formed from the fertilization events?
Answer Preview: One of the pollen nuclei fuses with the egg nucleus in the female gametophyte to …

, Chapter: 14 -Problem: 22 >> You have isolated a cDNA clone encoding a protein of interest in a higher eukaryote. This cDNA clone is not cleaved by restriction endonuclease EcoRI. When this cDNA is used as a radioactive probe for blot hybridization analysis of EcoRI-digested genomic DNA, three radioactive bands are seen on the resulting Southern blot. Does this result indicate that the genome of the eukaryote in question cont
Answer Preview: No. The genome of the species in question may contain …

, Chapter: 7 -Problem: 22 >> A Drosophila geneticist crossed females homozygous for three X-linked mutations (y, yellow body; B, bar eye shape; v, vermilion eye color) to wild-type males. The F1females, which had gray bodies and bar eyes with dark red pigment, were then crossed to y B+v males, yielding the following results:Determine the order of these three loci on the X chromosome and estimate the distances between them.
Answer Preview: The last two classes, consisting of yellow, bar flies and vermilion flies, with a total of …

, Chapter: 16 -Problem: 22 >> How do the reverse genetic approaches used to dissect biological processes differ from classical genetic approaches?
Answer Preview: Classical genetic approaches use mutational dissection to probe the functions of genes. Mut…

, Chapter: 13 -Problem: 31 >> Mutations in the genes encoding the ?- and ?-subunits of hemoglobin lead to blood diseases such as thalassemia and sickle-cell anemia. You have found a family in China in which some members suffer from a new genetic form of anemia. The DNA sequences at the 5? end of the nontemplate strand of the normal and mutant DNA encoding the ? subunit of hemoglobin are as follows: Normal 5-ACGTTATGCCGTACTGCCA
Answer Preview: (a) Frameshift due to the insertion of C at the 9th, 10th, or …

, Chapter: 9 -Problem: 21 >> The relationship between the melting Tm and GC content can be expressed, in its much simplified form, by the formula Tm = 69 + 0.41 (% GC).(a) Calculate the melting temperature of E. coli DNA that has about 50% GC.(b) Estimate the %GC of DNA from a human kidney cell where Tm = 85°C.
Answer Preview: (a) …

, Chapter: 16 -Problem: 3 >> How was the nucleotide sequence of the CF gene used to obtain information about the structure and function of its gene product?
Answer Preview: The CF gene was identified by map position-based cloni…

, Chapter: 14 -Problem: 5 >> Of what value are recombinant DNA and gene-cloning technologies to geneticists?
Answer Preview: Recombinant DNA and gene-cloning techniques allow geneticists to isolate essentially any gene or DNA …

, Chapter: 5 -Problem: 12 >> In Drosophila, vermilion eye color is due to a recessive allele (v) located on the X chromosome. Curved wings are due to a recessive allele (cu) located on one auto some, and ebony body is due to a recessive allele (e) located on another auto some. A vermilion male is mated to a curved, ebony female, and the F1 males are phenotypically wildtype. If these males were back crossed to curved, ebony fe
Answer Preview: P(male) = 1/2; P(male transmits fi…

, Chapter: 17 -Problem: 24 >> Would attenuation of the type that regulates the level of trp transcripts in E. coli be likely to occur in eukaryotic organisms?
Answer Preview: No. Since transcription (nucleus…

, Chapter: 11 -Problem: 3 >> What bases in the transcribed strand of DNA would give rise to the following mRNA base sequence: 5?-CUGAU-3??
Answer Preview: 3…

, Chapter: 16 -Problem: 18 >> Two men claim to be the father of baby Joyce Doe. Joyce’s mother had her CODIS STR DNA profile analyzed and was homozygous for allele 8 at the TPOX locus (allele 8 contains 8 repeats of the GAAT sequence at this polymorphic locus). Baby Joyce is heterozygous for alleles 8 and 11 at this locus. In an attempt to resolve the disputed paternity, the two men were tested for their STR DNA profiles at th
Answer Preview: The results cannot resolve the case of disputed paternity. Baby Joyce …

, Chapter: 11 -Problem: 18 >> A segment of DNA in E. coli has the following sequence of nucleotide pairs: When this segment of DNA is transcribed by RNA polymerase, what will be the sequence of nucleotides in the RNA transcript? Transcribed Image Text: 3'-A ACTGTACGTGCTACCTTGCTGATATTACT- TII!!|!||||||||||||||||I|I!|||| 5'-T?GACA
Answer Preview: Given the consensus 35 and 10 sequences in …

, Chapter: 16 -Problem: 20 >> Richard Meagher and coworkers have cloned a family of 10 genes that encode actins (a major component of the cytoskeleton) in Arabidopsis thaliana. The 10 actin gene products are similar, often differing by just a few amino acids. Thus, the coding sequences of the 10 genes are also very similar, so that the coding region of one gene will cross-hybridize with the coding regions of the other nine gen
Answer Preview: You can subclone the 3 noncoding regions (sequences between the translation-termination codons and t…

, Chapter: 15 -Problem: 21 >> You are given chromosome-specific cDNA libraries for all 24 human chromosomes. How might these libraries be used to study chromosome evolution in primates?
Answer Preview: The DNA sequences in human chromosome-specific cDNA libraries can be coupled to fluorescent …

, Chapter: 3 -Problem: 23 >> The following pedigree shows the inheritance of a recessive trait. Unless there is evidence to the contrary, assume that the individuals who have married into the family do not carry the recessive allele. What is the chance that the offspring of the following matings will show the trait: (a) III-1 × III-12; (b) II-4 × III-14; (c) III-6 × III-13; (d) IV-1 × IV-2?
Answer Preview: (a) (1/2) (1/4) = 1/8; (b…

, Chapter: 15 -Problem: 13 >> What were the goals of the Human Genome Project? What impact has achieving these goals had on the practice of medicine to date? What are some of the predicted future impacts? What are some of the possible misuses of human genome data?
Answer Preview: The goals of the Human Genome Project were to prepare genetic and physical maps showing …

, Chapter: 1 -Problem: 8 >> What is the difference between transcription and translation?
Answer Preview: Transcription is the production of an R…

, Chapter: 6 -Problem: 27 >> In Drosophila, the autosomal genes cinnabar (cn) and brown (bw) control the production of brown and red eye pigments, respectively. Flies homozygous for cinnabar mutations have bright red eyes, flies homozygous for brown mutations have brown eyes, and flies homozygous for mutations in both of these genes have white eyes. A male homozygous for mutations in the cn and bw genes has bright red eyes be
Answer Preview: The sons will have bright red eyes because …

, Chapter: 16 -Problem: 5 >> Myotonic dystrophy (MD), occurring in about 1 of 8000 individuals, is the most common form of muscular dystrophy in adults. The disease, which is characterized by progressive muscle degeneration, is caused by a dominant mutant gene that contains an expanded CAG repeat region. Wild-type alleles of the MD gene contain 5–30 copies of the trinucleotide. Mutant MD alleles contain 50 to over 2000 copies
Answer Preview: Oligonucleotide primers complementary to DNA sequences on both sides (upstream and downstream) of th…

, Chapter: 13 -Problem: 18 >> In a given strain of bacteria, all of the cells are usually killed when a specific concentration of streptomycin is present in the medium. Mutations that confer resistance to streptomycin occur. The streptomycin-resistant mutants are of two types: some can live with or without streptomycin; others cannot survive unless this drug is present in the medium. Given a streptomycin-sensitive strain of th
Answer Preview: Irradiate the nonresistant strain and plate the irradiated organisms o…

, Chapter: 3 -Problem: 28 >> A geneticist crosses tall pea plants with short pea plants. All the F1 plants are tall. The F1 plants are then allowed to self-fertilize, and the F2 plants are classified by height: 62 tall and 26 short. From these results, the geneticist concludes that shortness in peas is due to a recessive allele (s) and that tallness is due to a dominant allele (S). On this hypothesis, 2/3 of the tall F2 plant
Answer Preview: (a) The observed numbers, expected numbers, and chisquare calculation are laid out in the following …

, Chapter: 7 -Problem: 29 >> Drosophila females heterozygous for three recessive mutations, a, b, and c, were crossed to males homozygous for all three mutations. The cross yielded the following results:Construct a linkage map showing the correct order of these genes and estimate the distances between them. Transcribed Image Text:
Answer Preview: From the parental classes, + + c and a b +, the heterozygous females must have …

, Chapter: 3 -Problem: 7 >> In rabbits, the dominant allele B causes black fur and the recessive allele b causes brown fur; for an independently assorting gene, the dominant allele R causes long fur and the recessive allele r (for rex) causes short fur. A homozygous rabbit with long, black fur is crossed with a rabbit with short, brown fur, and the offspring are intercrossed. In the F2, what proportion of the rabbits with lo
Answer Preview: Among the F 2 progeny with long, bl…

, Chapter: 8 -Problem: 14 >> How can bacterial genes be mapped by interrupted mating experiments?
Answer Preview: By interrupting conjugation at various times afte…

, Chapter: 18 -Problem: 12 >> Using the techniques of genetic engineering, a researcher has constructed a fusion gene containing the heat-shock response elements from a Drosophila hsp70 gene and the coding region of a jellyfish gene (gfp) for green fluorescent protein. This fusion gene has been inserted into the chromosomes of living Drosophila by the technique of transposon-mediated transformation. Under what conditions will
Answer Preview: The green fluor…

, Chapter: 15 -Problem: 3 >> What is a contig? What is an RFLP? What is a VNTR? What is an STS? What is an EST? How is each of these used in the construction of chromosome maps?
Answer Preview: A contig (contiguous clones) is a physical map of a chromosome or part of a chromosome prepared from …

, Chapter: 6 -Problem: 11 >> A woman with X-linked color blindness and Turner syndrome had a color-blind father and a normal mother. In which of her parents did nondisjunction of the sex chromosomes occur?
Answer Preview: Nondisjunction must have occurred in the m…

, Chapter: 3 -Problem: 15 >> Albinism in humans is caused by a recessive allele a. From marriages between people known to be carriers (Aa) and people with albinism (aa), what proportion of the children would be expected to have albinism? Among three children, what is the chance of one without albinism and two with albinism?
Answer Preview: Half the children from Aa aa mating…

, Chapter: 13 -Problem: 30 >> How do acridine-induced changes in DNA result in inactive proteins?
Answer Preview: Mutations induced by acridine dyes are primarily insertions or del…

, Chapter: 10 -Problem: 4 >> A DNA template plus primer with the structure(where P = a phosphate group) is placed in an in vitro DNA synthesis system (Mg2+, an excess of the four deoxyribonucleoside triphosphates, etc.) containing a mutant form of E. coli DNA polymerase I that lacks exonuclease activity. The polymerase and exonuclease activities of this aberrant enzyme are identical to those of normal E. coli DNA polymerase I
Answer Preview: (a) Note that DNA synthesis will not occur on the left end since the 3-terminus of …

, Chapter: 18 -Problem: 24 >> An RNA interference-like phenomenon has been implicated in the regulation of transposable elements. In Drosophila, two of the key proteins involved in this regulation are encoded by the genes aubergine and piwi. Flies that are homozygous for mutant alleles of these genes are lethal or sterile, but flies that are heterozygous for them are viable and fertile. Suppose that you have strains of Drosoph
Answer Preview: The aubergine and piwi gene products mediate the RNAilik…

, Chapter: 13 -Problem: 26 >> You are screening three new pesticides for potential mutagenicity by using the Ames test. Two hisˆ’ strains resulting from either a frameshift or a transition mutation were used and produced the following results (number of revertant colonies):What type of mutations, if any, do the three pesticides induce? Transcribed Imag
Answer Preview: P #1 x Causes transition mutation. Liver enzymes convert it into …

, Chapter: 1 -Problem: 6 >> A gene contains 141 codons. How many nucleotides are present in the gene’s coding sequence? How many amino acids are expected to be present in the polypeptide encoded by this gene?
Answer Preview: There are 3 141 = 423 n…

, Chapter: 2 -Problem: 10 >> Arrange the following events in the correct temporal sequence during eukaryotic cell division, starting with the earliest: (a) condensation of the chromosomes,(b) Movement of chromosomes to the poles, (c) Duplication of the chromosomes, (d) Formation of the nuclear membrane, (e) Attachment of microtubules to the kinetochores, (f) Migration of centrosomes to positions on opposite sides of the nucle
Answer Preview: (c) Duplication of the chromosomes, (f) Migration of centr…

, Chapter: 11 -Problem: 12 >> Match one of the following terms with each of the descriptions given below. Terms: (1) sigma (s) factor; (2) poly(A) tail; (3) TATAAT; (4) exons; (5) TATAAAA; (6) RNA polymerase III; (7) intron; (8) RNA polymerase II; (9) heterogeneous nuclear RNA (hnRNA); (10) snRNA; (11) RNA polymerase I; (12) TTGACA; (13) GGCCAATCT (CAAT box). Descriptions: (a) Intervening sequence found in many eukaryotic gene
Answer Preview: (a) 7; (b) 5; (c) …

, Chapter: 1 -Problem: 3 >> Which bases are present in DNA? Which bases are present in RNA? Which sugars are present in each of these nucleic acids?
Answer Preview: The bases present in DNA are adenine, t… <

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