Principles of Genetics 7th edition D. Peter Snustad, Michael J. Simmons - Solutions

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? 3'ATATTTACGIGCTACCITGCTGATAGGAC T- |||||||||||||||| | || |||| ||||| || 5-TÀTÀÀ ÁŤĠČÁ
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? 3'-A ACTGTACGTGCTACCTTGCTGATATTACT- TII!!|!||||||||||||||||I|I!||||
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? 3'A TATTACTGCAATGGGCTGTATCG- III!!||!!|||I|||||!||||II 5'-TATAATGÅĊĠİTÀĊĊĊĠÅČATAGC-
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? 3'-A TGCTACTGCTATTCGCTGTATCG-51
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 is the function of the introns in eukaryotic genes?
(a) Which of the following nuclear pre-mRNA nucleotide sequences potentially contains an intron?(1) 5′-UGACCAUGGCGCUAACACUGCCAAU UGGCAAUACUGACCUGAUAGCAUCAGCCAA-3′ (2) 5′-UAGUCUCAUCUGUCCAUUGACUUCGAAA CUGAAUCGUAACUCCUACGUCUAUGGA-3′(3) 5′-UAGCUGUUUGUCAUGACUGACUGGUCA
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)
What bases in the transcribed strand of DNA would give rise to the following mRNA base sequence:5′-CUGAU-3′?
What bases in the mRNA transcript would represent the following DNA template sequence: 5′-TGCAGACA-3′?
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
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
You have identified a mutant E. coli strain that cannot synthesize histidine (Hisˆ’). To determine the location of the hisˆ’mutation on the E. coli chromosome, you perform interrupted mating experiments with five different Hfr strains. The following chart shows the time of entry
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
Bacteriophage P1 mediates generalized transduction in E. coli. A P1 transducing lysate was prepared by growing P1 phage on pur+ pro- his- bacteria. Genes pur, pro, and his encode enzymes required for the synthesis of purines, proline, and histidine, respectively. The phage and transducing particles
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
An F+strain, marked at 10 loci, gives rise spontaneously to Hfr progeny whenever the F factor becomes incorporated into the chromosome of the F+strain. The F factor can integrate into the circular chromosome at many points, so that the resulting Hfr strains transfer the genetic markers in different
In E. coli, the ability to utilize lactose as a carbon source requires the presence of the enzymes b-galactosidase and b-galactoside permease. These enzymes are encoded by two closely linked genes, lacZ and lacY, respectively. Another gene, proC, controls, in part, the ability of E. coli cells to
What does the term cotransduction mean? How can cotransduction frequencies be used to map genetic markers?
How can bacterial genes be mapped by interrupted mating experiments?
What roles do IS elements play in the integration of F factors?
What are the basic differences between generalized transduction and specialized transduction?
(a) Of what use are F′ factors in genetic analysis? (b) How are F′ factors formed?(c) By what mechanism does sexduction occur?
(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?
Assume that you have just demonstrated genetic recombination (e.g., when a strain of genotype a b+ is present with a strain of genotype a+ b, some recombinant genotypes, a+ b+ and a b, are formed) in a previously unstudied species of bacteria. How would you determine whether the observed
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
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+
Geneticists have used mutations that cause altered phenotypes such as white eyes in Drosophila, white flowers and wrinkled seeds in peas, and altered coat color in rabbits to determine the locations of genes on the chromosomes of these eukaryotes. What kinds of mutant phenotypes have been used map
In what way does the integration of the λ chromosome into the host chromosome during a lysogenic infection differ from crossing over between homologous chromosomes?
How does the structure of the λ prophage differ from the structure of the λ chromosome packaged in the λ head?
The following pedigree, described in 1938 by B. Rath, shows the inheritance of X-linked color blindness and hemophilia in a family. What are the possible genotypes of II-1? For each possible genotype, evaluate the children of II-1 for evidence of recombination between the color blindness and
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? Key to phenotypes: O
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. Phenotype Number 75
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?
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
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) 16223478Assume that arrangement (a) is the original one. In what order did the other arrangements most likely
A woman carries the androgen-insensitivity mutation (ar) on one of her X chromosomes; the other X carries the wild-type allele (AR). If the woman marries a normal man, what fraction of her children will be phenotypically female? Of these, what fraction will be fertile?
Assuming that the β-globin chain and the α-globin chain shared a common ancestor, what mechanisms might explain the differences that now exist in these two chains? What changes in DNA and mRNA codons would account for the differences that have resulted in unlike amino acids at corresponding
In a given strain of bacteria, all of the cells are usually killed when a specific concentration of streptomycin ispresent in the medium. Mutations that confer resistance to streptomycin occur. The streptomycin-resistantmutants are of two types: some can live with or without streptomycin; others
One stock of fruit flies was treated with 1000 roentgens (r) of X-rays. The X-ray treatment increased the mutation rate of a particular gene by 2 percent. What percentage increases in the mutation rate of this gene would be expected if this stock of flies was treated with X-ray doses of 1500 r,
Why does the frequency of chromosome breaks induced by X-rays vary with the total dosage and not with the rate at which it is delivered?
A reactor overheats and produces radioactive tritium (H3), radioactive iodine (I131), and radioactive xenon (Xn133). Why should we be more concerned about radioactive iodine than the other two radioactive isotopes?
One person was in an accident and received 50 roentgens (r) of X-rays at one time. Another person received 5 r in each of 20 treatments. Assuming no intensity effect, what proportionate number of mutations would be expected in each person?
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?
You are screening three new pesticides for potential mutagenicity by using the Ames test. Two hisˆ’ strainsresulting 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
How does the action and mutagenic effect of 5-bromouracil differ from that of nitrous acid?
Sydney Brenner and A. O. W. Stretton found that nonsense mutations did not terminate polypeptide synthesis in the rII gene of the bacteriophage T4 when these mutations were located within a DNA sequence interval in which a single nucleotide insertion had been made on one end and a single nucleotide
Seymour Benzer and Ernst Freese compared spontaneous and 5-bromouracil-induced mutants in the rII gene of the bacteriophage T4; the mutagen increased the mutation rate (rII+ → rII) several hundred times above the spontaneous mutation rate. Almost all (98 percent) of the 5-bromouracil-induced
How do acridine-induced changes in DNA result in inactive proteins?
Mutations in the genes encoding the α- and β-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
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?
Would such mutations occur if a nonreplicating suspension of MS2 phage was treated with 5-bromouracil?
Recall that nitrous acid deaminates adenine, cytosine, and guanine (adenine → hypoxanthine, which base-pairs with cytosine; cytosine → uracil, which base-pairs with adenine; and guanine → xanthine, which base-pairs with cytosine). Would you expect nitrous acid to induce any mutations that
Keeping in mind the known nature of the genetic code, the information given about phage MS2 in Problem13.32, 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
Would you expect nitrous acid to induce a higher frequency of Tyr → Ser or Tyr → Cys substitutions? Why?
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?
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
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,
Eight independently isolated mutants of E. coli, all of which are unable to grow in the absence of histidine (hisˆ’), were examined in all possible cis and trans heterozygotes (partial diploids). All of the cis heterozygotes were able to grow in the absence of histidine. The trans
Assume that the mutants described in Problem 13.41 yielded the following results. How many genes would they have defined? Which mutations would have been in the same gene(s)?
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
The loz (lethal on Z) mutants of bacteriophage X are conditional lethal mutants that can grow on E. coli strain Y but cannot grow on E. coli strain Z. The results shown in the following table were obtained when seven loz mutants were analyzed for complementation by infecting E. coli strain Z with
(a) In what ways is the introduction of recombinant DNA molecules into host cells similar to mutation?(b) In what ways is it different?
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
If the sequence of base pairs along a DNA molecule occurs strictly at random, what is the expected frequency of a specific restriction enzyme recognition sequence of length (a) Four and (b) Six base pairs?
In what ways do restriction endonucleases differ from other endonucleases?
Of what value are recombinant DNA and gene-cloning technologies to geneticists?
What determines the sites at which DNA molecules will be cleaved by a restriction endonuclease?
Restriction endonucleases are invaluable tools for biologists. However, genes encoding restriction enzymes obviously did not evolve to provide tools for scientists. Of what possible value are restriction endonucleases to the microorganisms that produce them?
Why is the DNA of a microorganism not degraded by a restriction endonuclease that it produces, even though its DNA contains recognition sequences normally cleaved by the endonuclease?
One of the procedures for cloning foreign DNA segments takes advantage of restriction endonucleases such as HindIII that produce complementary singlestranded ends. These enzymes produce identical complementary ends on cleaved foreign DNAs and on the vector DNAs into which the foreign DNAs are
You are working as part of a research team studying the structure and function of a particular gene. Your job is to clone the gene. A restriction map is available for the region of the chromosome in which the gene is located; the map is as follows:Your first task is to prepare a genomic DNA library
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?
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
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.
(a) What experimental procedure is carried out in Southern, northern, and western blot analyses? (b) What is the major difference between Southern, northern, and western blot analyses?
What major advantage does the polymerase chain reaction (PCR) have over other methods for analyzing nucleic acid structure and function?
The cloning vectors in use today contain an origin of replication, a select able marker gene (usually an antibiotic- resistance gene), and one additional component. What is this component, and what is its function?
The drawing in this problem shows a restriction map of a segment of a DNA molecule. Eco refers to locations where the restriction endonuclease EcoRI cuts the DNA, and Pst refers to locations where the restriction enzyme PstI cuts the DNA. Potential restriction sites are numbered 1€“6.
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
Distinguish between a genetic map, a cytogenetic map, and a physical map. How can each of these types of maps be used to identify a gene by positional cloning?
In the technique of positional cloning, a researcher begins with a DNA library and selects a clone that is tightly linked to the gene of interest. That clone, or a piece of it, is then used as a probe to isolate an overlapping clone from a different DNA library. The second clone is used to isolate
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?
The following is a Southern blot of EcoRI-digested DNA of rye plants from two different inbred lines, A and B.Developed autoradiogram I shows the bands resulting from probing the blot with 32P-labeled cDNA1. Autoradiogram II shows the same Southern blot after it was stripped of probe and reprobed
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
What are STRs? Why are they sometimes called microsatellites?
VNTRs and STRs are specific classes of polymorphisms. What is the difference between a VNTR and an STR?
An RFLP and a mutant allele that causes albinism in humans cannot be shown to be separated by recombination based on pedigree analysis or by radiation hybrid mapping. Do these observations mean that the RFLP occurs within or overlaps the gene harboring the mutation that causes albinism? If so, why?
You have just isolated a mutant of the bacterium Shigella dysenteriae that is resistant to the antibiotic kanamycin, and you want to characterize the gene responsible for this resistance. Design a protocol using genetic selection to identify the gene of interest.
What has this analysis revealed? What are the genotypes of the three different types of DNA samples?
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?
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?
What difficulty does repetitive DNA pose for the assembly of whole genome shotgun sequences by computer analysis?
Which type of molecular marker, RFLP or EST, is most likely to mark a disease-causing mutant gene in humans? Why?
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
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
What major advantage does the green fluorescent protein of the jellyfish have over other methods for studying protein synthesis and localization?
You are given chromosome-specific cDNA libraries for all 24 human chromosomes. How might these libraries be used to study chromosome evolution in primates?
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?
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

Showing 100 - 200 of 617

Principles of Genetics 7th edition D. Peter Snustad, Michael J. Simmons - Solutions

Step by Step Answers