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17.1 Multiple-Choice Questions
1) Which of the following statements correctly describes Archibald Garrod’s hypothesis for how “inborn errors of metabolism” such as alkaptonuria occur? D
2) A particular triplet of bases in the template strand of DNA is 5′-AGT-3′. What would be the corresponding codon for the mRNA that is transcribed? A
3) The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true? A
4) The figure shows a simple metabolic pathway. According to Beadle and Tatum’s hypothesis, how many genes are necessary for this pathway? B
5) Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on medium supplemented with which of the following nutrient(s)? B
6)Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme B would be able to grow on medium supplemented with which of the following nutrient(s)?C
7) Which of the following sequences of nucleotides are possible in the template strand of DNA that would code for the polypeptide sequence Phe-Leu-Ile-Val? D
8) What amino acid sequence will be generated, based on the following mRNA codon sequence?
5′-AUG-UCU-UCG-UUA-UCC-UUG-3′ D
9) Refer to the figure. Which of the triplets below is a possible anticodon for a tRNA that transports proline to a ribosome? C
10) Which of the following statements supports the one gene-one enzyme hypothesis? A
11) Which of the following characteristics is directly related to the coding of a single amino acid during the process of translation? C
12) Which of the following processes occurs during transcription? B
13) Which of the following molecular structures contain codons? B
14) The genetic code is redundant. What is meant by this statement? D
15) Once researchers identified DNA as the molecule responsible for transmitting heritable traits, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. Which of the following statements correctly describes the mechanism of information transfer in eukaryotes that accomplishes this task? B
16) According to the central dogma, what is the intermediate molecule involved in the flow of information in a cell that should go in the blank? C
17) Codons are three-base sequences in mRNA that specify the addition of a single amino acid to the growing protein chain during translation. How do eukaryotic codons and prokaryotic codons compare? D
18) Which of the following processes occurs in prokaryotes but not in eukaryotes? B
19) Which of the following statements best describes the termination of transcription in prokaryotes? B
20) In eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein? B
21) Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase? C
22) Which of the following statements best describes the significance of the TATA box in the promoters of eukaryotes? A
23) Which of the following processes occurs in eukaryotic gene expression? C
24) Which of the following statements correctly describes a ribozyme? B
25) Which of the following processes correctly describes alternative RNA splicing? B
26) In the structural organization of many eukaryotic genes, individual exons may be related to which of the following? C
27) In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed its 5′ cap and poly-A tail. Which of the following processes would you expect her to find to have occurred? D
28) Which components of the previous molecule will also be found in mRNA in the cytosol? C
29) Which one of the following statements about RNA processing is correct? B
30) How does the primary transcript in the nucleus of a eukaryotic cell compare to the functional mRNA? B
31) How does the primary transcript in the nucleus of a prokaryotic cell compare to the functional mRNA? D
32) A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is ________. D
33) Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________. D
34) What would be the consequence of a mutation in a bacterial cell that produces a defective aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA? B
35) In bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. Which of the following statements explains this fact? B
36) Which of the following processes is the first event to take place in translation in eukaryotes? D
37) Which of the following statements correctly describes the function of a signal peptide? C
38) What is the function of the release factor during translation in eukaryotes? A
39) Which of the following dipeptides will form from this mRNA? B
40) Which of the following anticodons in the first tRNA to bind will complement this mRNA? A
41) What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure? B
42) The figure represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid? D
43) The tRNA shown in the figure has its 3′ end projecting beyond its 5′ end. Which of the following processes will occur at this 3′ end? A
44) Which of the following properties is associated with a protein that will be secreted from a eukaryotic cell? B
45) Which of the following molecules are required for the process of translation? C
46) During the elongation phase of translation, which site in the ribosome represents the location where a codon is being read? C
47) Once a peptide bond has been formed between the amino acid attached to the tRNA in the P site and the amino acid associated with the tRNA in the A site, what process occurs next? A
48) Which one of the following structures, if missing, would usually prevent translation from starting? C
49) Which of the following processes occurs when termination of translation takes place? B
50) Post-translational modifications of proteins may include which of the following processes? D
51) Which of the following statements is true about protein synthesis in prokaryotes? B
52) Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product? B
53) Which of the following statements correctly describes the effect a nonsense mutation would have on a gene? C
54) Which of the following DNA mutations is most likely to damage the protein it specifies? A
55) The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the result of this type of mutation? C
56) Which of the following statements is the most current description of a gene? C
57) How might a single base substitution in the sequence of a gene affect the amino acid sequence of a protein encoded by the gene? A
58) An original section of DNA has the base sequence AGCGTTACCGT. A mutation in this DNA strand results in the base sequence AGGCGTTACCGT. What type of mutation does this change represent? D
59) A single base substitution mutation is likely to have a less deleterious effect when the base change exhibits which of the following results? B
60) Rank the following one-base point mutations with respect to their likelihood of affecting the structure of the corresponding polypeptide (from most likely to least likely). B
17.2 Student Edition End-of-Chapter Questions
1) In eukaryotic cells, transcription cannot begin until B
2) Which of the following is not true of a codon? C
3) The anticodon of a particular tRNA molecule is A
4) Which of the following is not true of RNA processing? A
5) Which component is not directly involved in translation? B
6) Using Figure 17.6, identify a 5′ → 3′ sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys. C
7) Which of the following mutations would be most likely to have a harmful effect on an organism? D
18.1 Multiple-Choice Questions
1) Which of the following molecules is a protein produced by a regulatory gene? D
2) Which of the following molecules helps to “turn off” genes in a cell? D
3) When taken up by a cell, which of the following molecules binds to a repressor so that the repressor no longer binds to the operator? A
4) Most repressor proteins are allosteric. Which of the following molecules binds with the repressor to alter its conformation and therefore affect its function? A
5) Which of the following processes would result from a mutation that deactivates a regulatory gene of a repressible operon in an E. coli cell? A
6) Which of the following conditions is most likely to cause the lactose operon to be transcribed? C
7) How does the transcription of structural genes in an inducible operon occur? B
8) For a repressible operon to be transcribed, which of the following conditions must occur? C
9) Altering patterns of gene expression in prokaryotes would most likely serve an organism’s survival by ________. C
10) In positive control of several sugar metabolism-related operons, the cAMP receptor protein (CRP) binds to DNA to stimulate transcription. Which of the following environmental conditions causes an increase in CRP activity in stimulating transcription? B
11) There is a mutation that is found in E. coli in the repressor that results in a molecule known as a super-repressor because it represses the lacoperon permanently. Which of the following characteristics would you expect to observe in such a mutant? C
12) Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If a researcher moves the promoter for the lac operon to the region between the beta galactosidase (lacZ) gene and the permease (lacY) gene, which of the following results would be most likely? D
13) Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If a researcher moves the operator to the far end of the operon, past the transacetylase (lacA) gene, which of the following processes would likely occur when the cell is exposed to lactose? D
14) Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If a researcher moves the repressor gene (lacI), along with its promoter, to a position at some several thousand base pairs away from its normal position, which of the following results would be expected? D
15) Which of the following results would occur if the repressor of an inducible operon were mutated so that it could not bind the operator? C
16) According to the lac operon model proposed by Jacob and Monod, what is predicted to occur if the operator is removed from the operon? A
17) Under what conditions does the trp repressor block transcription of the trp operon? B
18) How does extracellular glucose inhibit transcription of the lac operon? D
19) The cAMP receptor protein (CRP) is said to be responsible for positive regulation of the lac operon because ________. D
20) Imagine that you’ve isolated a yeast mutant that contains histones resistant to acetylation. What phenotype would you predict for this mutant? C
21) Which of the following statements correctly describes the primary difference between enhancers and proximal control elements? C
22) The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different ________. C
23) Gene expression is often assayed by measuring the level of mRNA produced from a gene. What level of the control of gene expression can by analyzed by this type of assay? B
24) Which of the following processes would allow the detection of alternative splicing of transcripts from a given gene? D
25) Which of the following mechanisms is used to coordinate the expression of multiple, related genes in eukaryotic cells? B
26) DNA methylation and histone acetylation are examples of which of the following processes? C
27) Which of the following functions are characteristic of general transcription factors in eukaryotes? A
28) How do steroid hormones produce their effects in cells? D
29) How are bacteria able to change their patterns of protein synthesis so quickly in response to environmental changes? A
30) A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments, she succeeded in increasing acetylation of histone tails in the chromatin of the cells. Which of the following results would she most likely see in these cells? B
31) A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. One of her colleagues suggested she try increased methylation of cytosine (C) nucleotides in the DNA of promoters of a mammalian system. Which of the following results would she most likely see? D
32) Which of the following methods is utilized by eukaryotes to control their gene expression that is different from the type of control found in bacteria? D
33) Which of the following processes destroys RNA molecules in a cell if they have a sequence complementary to an introduced double-stranded RNA? A
34) At the beginning of this century, there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. Many people were surprised that the number of protein-coding sequences was much smaller than they had expected. Which of the following types of DNA make up the rest of the human genome? C
35) Among the newly discovered small noncoding RNAs, one type helps to reestablish ethylation patterns during gamete formation and blocks expression of some transposons. Which of the following types of RNA is responsible for this function? B
36) Which of the following statements best describes the characteristics of siRNA? A
37) A researcher introduces double-stranded RNA into a culture of mammalian cells and can identify its location or that of its smaller subsections experimentally, using a fluorescent probe. Some time later, she finds that the introduced strand separates into single-stranded RNAs, one of which is degraded. What does this enable the remaining strand to do? B
38) A researcher introduces double-stranded RNA into a culture of mammalian cells and can identify its location or that of its smaller subsections experimentally, using a fluorescent probe. When she finds that the introduced strand separates into single-stranded RNAs, what other evidence of this single-stranded RNA piece’s activity would she find? B
39) The fact that plants can be cloned from somatic cells demonstrates that ________. A
40) Which of the following molecules are involved in pattern formation during development? A
41) What essential information does the product of the bicoid gene in Drosophila provide during development? D
42) What would be the result of a mutation in a maternal effect gene in a female Drosophila? B
43) Mutations in which of the following genes lead to transformations in the identity of entire body parts? C
44) Which of the following are maternal effect genes that control the orientation of the egg and thus the Drosophila embryo? C
45) The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following developmental events would occur? C
46) In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated? B
47) Which of the following statements describes a cell that is considered to be differentiated? C
48) When the Bicoid protein is expressed in Drosophila, divisions between cells in the embryo are not yet fully developed. This information helps to explain which observation by Nüsslein-Volhard and Wieschaus? B
49) Which axis in the embryo does the protein product of the bicoid gene in Drosophila determine? A
50)Which of the following types of mutation would convert a proto-oncogene into an oncogene? C
51) Which of the following processes do normal proto-oncogenes typically exhibit? C
52) Which of the following functions does the product of the p53 gene carry out? A
53) Which of the following statements correctly describes a characteristic of tumor-suppressor gene? C
54) Why are BRCA1 and BRCA2 considered to be tumor-suppressor genes? A
55) Forms of the Ras protein found in tumors usually cause which of the following events to occur? D
56) A genetic test to detect predisposition to cancer would likely examine the APC gene for involvement in which type(s) of cancer? A
18.2 Student Edition End-of-Chapter Questions
1) If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then C
2) Muscle cells differ from nerve cells mainly because they A
3) The functioning of enhancers is an example of B
4) Cell differentiation always involves C
5) Which of the following is an example of post-transcriptional control of gene expression? C
6) What would occur if the repressor of an inducible operon were mutated so it could not bind the operator? D
7) Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts. This is evidence that the product of the bicoid gene A
8) Which of the following statements about the DNA in one of your brain cells is true? C
9) Within a cell, the amount of protein made using a given mRNA molecule depends partly on B
10) Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potential time bombs in eukaryotic cells? D
20.1 Multiple-Choice Questions
1) Which of the following processes helps bacterial cells protect their own DNA from restriction enzymes (endonucleases)? A
2) What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? B
3) A principal problem with inserting an unmodified mammalian gene into a plasmid and then getting that gene expressed in bacteria is that ________. C
4) Why are yeast cells frequently used as hosts for cloning? D
5) Why is sequencing an entire genome, such as that of C. elegans, a nematode, important for genetic research? C
6) Which of the following methods would be most successful in attempting to introduce a particular piece of DNA into an animal cell? A
7) Why is it so important to be able to amplify DNA fragments when studying genes? B
8) Pax-6 is a gene that is involved in eye formation in many invertebrates, such as Drosophila. Pax-6 is also found in vertebrates. A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6) leads to a compound fly eye. This information suggests which of the following characteristics of this gene? C
9) Which of the following characteristics of Taq polymerase make it useful in the PCR process? A
10) Which of the following enzymes was used to produce the molecule of DNA in the figure? B
11) The segment of DNA shown in the figure has restriction sites I and II, which create restriction fragments A, B, and C. Which of the gels produced by electrophoresis best represents the separation and identity of these fragments? B
12) For which of the following processes can dideoxyribonucleotides be used? C
13) Many identical copies of genes cloned in bacteria are produced as a result of which of the following processes? D
14) Which of the following sequences is most likely to be cut by a restriction enzyme? B
15) What information is critical to the success of polymerase chain reaction (PCR) itself? A
16) Which of the following correctly lists the processes in order for one cycle of polymerase chain reaction (PCR)? D
17) The final step in a Sanger DNA sequencing reaction is to run the DNA fragments on a gel. What purpose does this serve? D
18) How can a gene that contains introns be made shorter (but remain functional) for genetic engineering purposes? B
19) Which of the following enzymes is required to make complementary DNA (cDNA) from RNA? D
20) How have DNA microarrays made a huge impact on genomic studies? C
21) RNAi methodology uses double-stranded pieces of RNA to trigger breakdown of a specific mRNA or inhibit its translation. For which of the following processes might this technique be useful? A
22) Which of the following statements correctly describes how RNA interference (RNAi) silences selected genes? C
23) In large scale, genome-wide association studies in humans, what types of genetic markers do researchers look for? B
24) For a particular microarray assay (DNA chip), cDNA has been made from the mRNAs of a dozen patients’ breast tumor biopsies. Which of the following types of evidence will researchers be looking for in order to determine if the cells are cancerous? C
25) 5′-AACTTCGA-3′. Within a population, you discover that each of these sequences is common. Which of the following statements correctly describes theses sequences? A
26) Which of the following processes uses labeled probes to visualize the expression of genes in whole tissues and organisms? B
27) Which of the following processes is most like the formation of identical twins? D
28) In 1997, Dolly the sheep was cloned. Which of the following processes was used? C
29) Which of the following problems with animal cloning might result in premature death of the clones? C
30) Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning, there is a wider divergence of opinion. Which of the following statements provides a likely explanation? B
31) Which of the following statements correctly describes one of the main differences between embryonic stem cells and adult stem cells? B
32) A researcher is using adult stem cells and comparing them to other adult cells from the same tissue. Which of the following findings is likely from this comparison? A
33) In animals, what is the difference between reproductive cloning and therapeutic cloning? D
34) The first cloned cat, called Carbon Copy, was a calico, but she looked significantly different from her female parent. Why was this the case with this clone? D
35) In recent times, it has been shown that adult cells can be induced to become pluripotent stem cells (iPS). To make this conversion, what has been done to the adult cells? A
36) Suppose that a researcher is successful at producing induced pluripotent stem cells (iPS) for replacement of pancreatic insulin-producing cells for people with type 1 diabetes. Which of the following could still pose problems for this individual? D
37) Which of the following statements correctly describes one characteristic of genetically engineered plants? B
38) Scientists developed a set of guidelines to address the safety of DNA technology. Which of the following safety measures is one that has been adopted by researchers? A
39) Which of the following statements describes one of the technical reasons why gene therapy is problematic in humans? C
40) One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following issues is a possible hindrance that must be overcome in order for this process to work properly? A
41) Which of the following characteristics of short tandem repeats (STRs) DNA makes it useful for DNA fingerprinting? A
42) Transgenic mice are useful to human researchers because they ________. A
43) Which of the following information or processes does gene therapy require? B
44) What is the most favorable characteristic of retroviruses that makes them useful in gene therapy applications? C
45) Why might using retroviral vectors for gene therapy increase the patient’s risk of developing cancer? D
46) In the form of gene therapy used successfully for severe combined immunodeficiency syndrome, SCID-X1, how is the genetic engineering of human cells achieved? D
47) One predicted aspect of climate change is that climates, including precipitation and temperature, over most of Earth will become more variable. Which of the following is a good strategy for genetically engineering crops if this is true? C
48) Select an observation that best describes a correct aspect of the two processes of restriction
digest and gel electrophoresis. A
49) Select the appropriate condition to determine if the plasmid has entered the E. coli bacterial cell. C
20.2 Student Edition End-of-Chapter Questions
1) In DNA technology, the term vector can refer to D
2) Which of the following tools of DNA technology is incorrectly paired with its use? B
3) Plants are more readily manipulated by genetic engineering than are animals because C
4) A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). To compare a specific region of the DNA from a sample with DNA from living birds, which of the following would be most useful for increasing the amount of dodo DNA available for testing? B
5) DNA technology has many medical applications. Which of the following is not done routinely at present? C
6) Which of the following is not true of cDNA produced using human brain tissue as the starting material? B
7) Expression of a cloned eukaryotic gene in a bacterial cell involves many challenges. The use of mRNA and reverse transcriptase is part of a strategy to solve the problem of A
8) Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme? B
21.1 Multiple-Choice Questions
1) What is metagenomics? D
2) Which of the following processes is an early step in the whole-genome shotgun approach to sequencing? A
3) Using modern techniques of sequencing by synthesis and the shotgun approach, sequences are assembled into chromosomes by ________. C
4) Which of the following statements defines proteomics? B
5) Bioinformatics can be used to scan for short sequences that specify known mRNAs, called ________. A
6) Which of the following processes correctly describes gene annotation in bioinformatics? A
7) Bioinformatics includes ________. D
8) After finding a new medicinal plant, a pharmaceutical company decides to determine if the plant has genes similar to those of other known medicinal plants. What would annotation of the genome of this plant allow the company to determine? C
9) If the sequence of a cDNA has matches with DNA sequences in the genome, then this genomic DNA could be described by which of the following statements? A
10) Which of the following techniques would be most appropriate to test the hypothesis that humans and chimps differ in the expression of a large set of shared genes? A
11) What can proteomics reveal that genomics cannot? C
12) A sequence database such as GenBank could be used to carry out which of the following processes? B
13) Current analysis indicates that less than 2% of the human genome codes for proteins. Based on the systems approach employed by the ENCODE project, what percentage of the genome is estimated to be transcribed at some point in at least one cell type? C
14) Which of the following statements is a correct representation of gene density? C
15) Why might the cricket genome have eleven times as many base pairs as that of Drosophila melanogaster? C
16) Which of the following conclusions has led to the comparison between the number of human genes and those of other animal species? B
17) Why is it more difficult to identify eukaryotic genes than prokaryotic genes using genomic techniques? D
18) Which of the following statements correctly describes one of the characteristics of alternative splicing in vertebrate genomes? A
19) Which of the following statements correctly describes one characteristic of a multigene family? B
20) Which of the following statements correctly describes one characteristic of retrotransposons? A
21) In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. Why is this the case? A
22) Why is sequencing of eukaryotic genomes more difficult than sequencing genomes of bacteria or archaea? D
23) How do transposons and retrotransposons differ in how they move around in a genome? B
24) How do transposable elements and short tandem repeats (STRs) differ? C
25) Which of the following can be duplicated in a genome? D
26) Unequal crossing over during prophase I can result in one sister chromosome with a deletion and another with a duplication. A mutated form of hemoglobin, so-called hemoglobin Lepore, exists in the human population. Hemoglobin Lepore has a deleted series of amino acids. If this mutated form was caused by unequal crossing over, what would be an expected consequence? A
27) The figure shows a diagram of blocks of genes on human chromosome 16 and the locations of blocks of similar genes on four chromosomes of the mouse.
Which of the following statements describes the result of the movement of these blocks? D
28) Humans have 23 pairs of chromosomes, and chimps have 24 pairs of chromosomes. What is the most likely explanation for these differences in human and chimp genomes? A
29) During which of the following processes does exon shuffling occur? C
30) When gene duplication occurs to its ultimate extent by doubling all genes in a genome, which of the following results has occurred? C
31) Which of the following types of genes or gene families may be created by mutations that occur in one member of a gene pair that arose from gene duplication? D
32) Based on the data in the Amino Acid Sequence Identity Table, which two members of the human globin gene family are the most divergent? D
33) Fragments of DNA have been extracted from the remnants of extinct woolly mammoths, amplified, and sequenced. How can these fragments of DNA now be used? D
34) Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species. The homeobox is the code for the domain of a protein that binds to DNA in a regulatory developmental process. Which of the following statements is therefore correct regarding homeotic genes? A
35) A recent study compared the Homo sapiens genome with that of Neanderthals. The results of the study indicated that there was a mixing of the two genomes at some period in evolutionary history. Which of the following potential discoveries of additional data might be consistent with this hypothesis? B
36) Several of the different globin genes are expressed in humans, but at different times in development. Which of the listed mechanisms could allow for this? D
37) Biologists now routinely test for homology between genes in different species. If genes are determined to be homologous, how are they related to each other? A
38) A current view of how the human and chimpanzee can share most of their nucleotide sequences yet exhibit significant phenotypic differences is that many of the most important sequence differences alter ________. C
39) Studies in knockout mice have demonstrated an important role of the FOXP2 transcription factor in the development of vocalizations. Recent sequence comparisons of the FOXP2 gene in Neanderthals and modern humans show that while the DNA sequence may be different, the protein sequence it codes for is identical. Which of the following conclusions might logically be inferred from this information? C
40) Comparisons of DNA sequences within the human species have revealed many variations. Which of the following variations involves duplication of relatively long stretches of DNA? A
41) A microarray is a tool used in genetic research to determine the mRNAs being produced in a particular tissue, and their relative level of expression. Known genes can therefore be assayed for their expression in different situations. One use of the technology is in cancer diagnosis and treatment. If a known gene functions as a tumor suppressor, predict which of the following pieces of evidence would be most useful in diagnosis of a cancer due to a mutation in this tumor-suppressor gene. C
1) Bioinformatics includes all of the following except B
2) Homeotic genes A
3) Two eukaryotic proteins have one domain in common but are otherwise very different. Which of the following processes is most likely to have contributed to this similarity? C