Latest one exam 3(BIO)Answered

Latest one exam 3(BIO)Answered In the Hershey and Chase experiment, the pellet was radioactive after bacteria had been infected with 32P-labeled viruses and centrifuged. Why? A. Viruses were centrifuged to form the p ...

Latest one exam 3(BIO)Answered In the Hershey and Chase experiment, the pellet was radioactive after bacteria had been infected with 32P-labeled viruses and centrifuged. Why? A. Viruses were centrifuged to form the pellet, and they had incorporated radioactive proteins from the bacterial DNA. B. Viruses were centrifuged to form the pellet, and they had incorporated radioactive DNA. C. Bacteria were centrifuged to form the pellet, and they had incorporated radioactive DNA. D. Bacteria were centrifuged to form the pellet, and they had incorporated radioactive proteins into their cell membranes. E. Bacteria were centrifuged to form the pellet, and they had incorporated radioactive proteins into their DNA. {{ANS}}c Bacteria were centrifuged to form the pellet, and they had incorporated radioactive DNA. Which of the following nucleotide sequences represents the complementary sequence that would bind to the DNA strand 5' - TCATGG - 3'? a. 5' - GGTACT - 3' b. 5' - TTGCAG - 3' c. 3' - CCATGA - 5' d. 3' - TCATGG - 5' e. 3' - AGTACC - 5' {{ANS}}e. 3' - AGTACC - 5' The central dogma describes the flow of information of gene expression as a. protein → DNA → RNA. b. DNA → RNA → protein. c. RNA → DNA. d. DNA → protein → RNA. e. RNA → DNA → protein. {{ANS}}b. DNA → RNA → protein. During DNA replication, the _ strand is assembled in the _ direction that the DNA double helix unwinds and is produced by _ replication. a. lagging; opposite; discontinuous b. leading; same; discontinuous c. lagging; same; continuous d. leading; opposite; continuous e. leading; opposite; discontinuous {{ANS}}a. lagging; opposite; discontinuous Substitution of one base pair for another in a coding region of a gene can result in a ____________ mutation where the changed codon still codes for the same amino acid as the original codon did. a. chromosomal b. missense c. frameshift d. nonsense e. silent {{ANS}}e. silent Small ribonucleoprotein particles (snRNPs, or "snurps") are involved in ________. a. initiation of transcription b. initiation of translation c. mRNA splicing d. termination of translation e. aminoacylation of tRNA {{ANS}}c. mRNA splicing Stopping transcription in eukaryotes requires: a. generation of a poly-A tail. b. splicing introns out and exons together. c. generation of a stop codon. d. copying a terminator sequence in mRNA. e. activation of gene repressors. {{ANS}}a. generation of a poly-A tail. As a ribosome translocates along an mRNA molecule by one codon, which of the following occurs? a. The tRNA that was in the A site moves into the P site. b. The polypeptide enters the E site. c. The tRNA that was in the P site moves into the A site. d. The tRNA that was in the A site departs from the ribosome via a tunnel. e. The tRNA that was in the A site moves to the E site and is released. {{ANS}}a. The tRNA that was in the A site moves into the P site. RNA polymerase moves along the template strand of DNA in the _ direction of the template strand, and adds nucleotides to the _ end of the growing transcript. a. 3' to 5'; 5' b. 5' to 3'; 3' c. 3' to 5'; 3' d. 5' to 3'; 5' {{ANS}}c. 3' to 5'; 3' The DNA of an organism is studied and found to contain 36% cytosine. This organism should have _ % guanine and _ % adenine in its DNA. A. 14; 36 B. 14; 14 C. 86; 14 D. 36; 14 E. 36; 36 {{ANS}}D. 36; 14 The process of adding the correct amino acid onto a tRNA molecule is catalyzed by ________. a. the tRNA itself b. an mRNA c. the ribosome d. an aminoacyl-tRNA synthetase e. RNA polymerase {{ANS}}d. an aminoacyl-tRNA synthetase In roses assume that red or yellow flower color is controlled by a single gene with two alleles. Crossing roses with yellow flowers with each other yields only offspring that produce yellow flowers, but when you cross roses with red flowers with each other you sometimes get offspring that produce yellow flowers. If you take a rose plant that is heterozygous for the flower color gene and cross it with another rose plant with red flowers that has had yellow-flowered offspring in the past, what are the predicted fractions for the possible phenotypes of the offspring? a. 4/4 red, 0/4 yellow b. 1/2 red, 1/2 yellow c. 1/4 red, 3/4 yellow d. 3/4 red, 1/4 yellow e. 0/4 red, 4/4 yellow f. cannot be determined {{ANS}}d. 3/4 red, 1/4 yellow in humans, one form of polydactyly (extra fingers and toes) is controlled by a single autosomal gene with two possible alleles; the dominant allele leads to polydactyly, the recessive is for the normal number of fingers and toes. A woman with this form of polydactyly whose extra digits were removed when she was a baby mates with a man who also has this form of polydactyly and who also had his extra digits removed when he was a baby. Their first child is born with the normal number of fingers and toes. What the odds that their second child will also be born with the normal number of fingers and toes? Give your answer as a decimal fraction (for example, you would enter 0.85 for an 85% chance). a. .50 b. .25 c. 1.0 d. .75 {{ANS}}b. .25 3 In peas, the allele for tall (T) is dominant over short (t), and the unlinked gene for seed color has the allele for yellow seeds (G) dominant over green seeds (g). What is the predicted phenotypic ratio for offspring from this cross: TtGg x TtGg a - 1 tall, yellow: 1 tall, green b - 3 tall, yellow: 1 tall, green c - 1 short, yellow: 1 short, green d - 3 short, yellow: 1 short, green e - 1 tall, yellow: 1 short, yellow f - 3 tall, yellow: 1 short, yellow g - 1 tall, green: 1 short, green h - 3 tall, green: 1 short, green i - 1 tall, yellow: 1 tall, green: 1 short, yellow: 1 short, green j - 3 tall, yellow: 3 tall, green: 1 short, yellow: 1 short, green k - 3 tall, yellow: 1 tall, green: 3 short, yellow: 1 short, green l - 9 tall, yellow: 3 tall, green: 3 short, yellow: 1 short, green {{ANS}}l - 9 tall, yellow: 3 tall, green: 3 short, yellow: 1 short, green In peas, the allele for tall (T) is dominant over short (t), and the unlinked gene for seed color has the allele for yellow seeds (G) dominant over green seeds (g). What is the predicted phenotypic ratio for offspring from this cross: Ttgg x TtGg a. 1 tall, yellow: 1 tall, green b. 3 tall, yellow: 1 tall, green c. short, yellow: 1 short, green d. 3 short, yellow: 1 short, green e. 1 tall, yellow: 1 short, yellow f. 3 tall, yellow: 1 short, yellow g. 1 tall, green: 1 short, green h. 3 tall, green: 1 short, green i. 1 tall, yellow: 1 tall, green: 1 short, yellow: 1 short, green j. 3 tall, yellow: 3 tall, green: 1 short, yellow: 1 short, green k. 3 tall, yellow: 1 tall, green: 3 short, yellow: 1 short, green l. 9 tall, yellow: 3 tall, green: 3 short, yellow: 1 short, green {{ANS}}j. 3 tall, yellow: 3 tall, green: 1 short, yellow: 1 short, green In peas, the allele for tall (T) is dominant over short (t), and the unlinked gene for seed color has the allele for yellow seeds (G) dominant over green seeds (g). What is the predicted phenotypic ratio for offspring from this cross: Ttgg x ttGG a. 1 tall, yellow: 1 tall, green b. 3 tall, yellow: 1 tall, green c. 1 short, yellow: 1 short, green d. 3 short, yellow: 1 short, green e. 1 tall, yellow: 1 short, yellow f. 3 tall, yellow: 1 short, yellow g. 1 tall, green: 1 short, green h. 3 tall, green: 1 short, green i. 1 tall, yellow: 1 tall, green: 1 short, yellow: 1 short, green j. 3 tall, yellow: 3 tall, green: 1 short, yellow: 1 short, green k. 3 tall, yellow: 1 tall, green: 3 short, yellow: 1 short, green l. 9 tall, yellow: 3 tall, green: 3 short, yellow: 1 short, green {{ANS}}e. 1 tall, yellow: 1 short, yellow One gene determines red vs. white flowers in pea plants, and another determines axial vs. terminal flowers. Two true-breeding stocks of pea plants are crossed. One parent has red, axial flowers and the other has white, terminal flowers; all F1 individuals have red, axial flowers. If you perform a cross between two of these F1 individuals, approximately what fraction of the offspring should have red, terminal flowers? (Assume independent assortment). Give your answer as a fraction (for example, you would enter 1/10 for a 10% chance). a. 3/16 b. 8/16 c. ¼ {{ANS}}a. 3/16 (NOTE: This data in this question were made up by Dr. Bowling.) In humans, the gene for cystic fibrosis is linked to a gene for a rare form of "blue/yellow" colorblindness. Both of these are recessive. In a study of a small population, several matings were recorded between individuals heterozygous for both genes and individuals with both cystic fibrosis and blue/yellow colorblindness. The offspring phenotypes were recorded as follows: 41 % without cystic fibrosis and with normal color vision 9 % without cystic fibrosis and with blue/yellow colorblindness 7 % with cystic fibrosis and with normal color vision 43 % with both cystic fibrosis and blue/yellow colorblindness Based on these data, what is the map distance between the genes for these two traits? a. 30 b. 16 c. 24 d. 6 e. 2 {{ANS}}b. 16 A woman is red-green colorblind, and she mates with a man who has normal color vision. Knowing that red-green colorblindness is controlled by a gene on the X chromosome, what can you predict for their children with regard to inheritance of color vision? a. all of the boys and half of the girls will be colorblind. b. half of the boys and none of the girls will be colorblind. c. all of the children will be colorblind. d. all of the boys and none of the girls will be colorblind. e. half of the boys and half of the girls will be colorblind. {{ANS}}d. all of the boys and none of the girls will be colorblind. A woman with normal color vision, but whose father is red-green colorblind, mates with a man who is red-green colorblind. Knowing that red-green colorblindness is controlled by a gene on the X chromosome, what can you predict for their children with regard to inheritance of color vision? a. all of the boys and half of the girls will be colorblind. b. half of the boys and none of the girls will be colorblind. c. all of the children will be colorblind. d. all of the boys and none of the girls will be colorblind. e. half of the boys and half of the girls will be colorblind.{{ANS}}e. half of the boys and half of the girls will be colorblind In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male? a. black females; orange males b. tortoiseshell females; orange males c. tortoiseshell females; black males d. orange females; black males e. tortoiseshell females; tortoiseshell males{{ANS}}c. tortoiseshell females; black males Recall that the gene for red or white eye color in fruit flies is X-linked, with the white color allele recessive. You examine a vial of 100 flies that are all offspring from a single genetic cross. In the vial you find that all females are red-eyed, while the males are about half red-eyed and half white-eyed. The genotypes of the parents were: a. XRXR ; XRY b. XRXr ; XRY c. XrXr ; XRY d. XRXR ; XrY e. XRXr ; XrY{{ANS}}b. XRXr ; XRY In snapdragons, heterozygotes have pink flowers, whereas homozygotes have either red or white flowers. When a pink-flowered snapdragon is crossed with a red-flowered snapdragon, what proportion of the offspring will have white flowers? Give your answer as a decimal fraction (for example, you would enter 0.25 for a 25% chance). a. 5 b. 8 c. 3 d. 0{{ANS}}d. 0 A man and a woman each have a parent with type O blood. He has type A blood, and she has type B blood. If this man and woman have children, what is the predicted phenotype ratio for their offspring with respect to blood type? a. 1/2 A: 1/2 B b. all AB c. 1/4 A: 1/4 B: 1/4 AB: 1/4 O d. 1/2 A: 1/4 B: 1/4 AB d. 1/2 A: 1/2 AB{{ANS}}c. 1/4 A: 1/4 B: 1/4 AB: 1/4 O In a rodent species from an island in the south Atlantic there are three different coat colors found in the population. Studies show that two genes (each with two alleles) determine the coat color in this species, and a dihybrid cross produces offspring with the coat colors in a 9:3:4 ratio. This is an example of a. epistasis. b. genetic linkage. c. pleiotropy. d. codominance or incomplete dominance. e. multiple alleles.{{ANS}}a. epistasis. When columbines with lavender flowers are mated they produce offspring that make either dark purple, lavender, or white flowers. The ratio is 1 dark purple: 2 lavender: 1 white. This is an example of what kind of non-Mendelian inheritance pattern? a. epistasis b. genetic linkage c. pleiotropy d. codominance or incomplete dominance e. multiple alleles{{ANS}}d. codominance or incomplete dominance Which of the following are part of Darwin's mechanism of evolution? a. competition among organisms b. differential reproductive success c. overproduction of offspring d. acquiring traits because they are needed e. genetic variation among individuals{{ANS}}a ,b, c, e Natural selection is based on which of the following? a. populations tend to produce more individuals than the b. environment can support. b. genetic variation exists within populations. c. individuals adapt to their environments and, thereby, evolve. d. individuals who survive longer tend to produce more offspring than those who die young. e. the best-adapted individuals tend to produce the most offspring.{{ANS}}a, b, d, e Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus? a. The environment is responsible for natural selection. b. Earth is more than 10,000 years old. c. Populations tend to increase at a faster rate than their food supply normally allows. d. Earth changed over the years through a series of catastrophic upheavals. e. All species are fixed in the form in which they are created.{{ANS}}c. Populations tend to increase at a faster rate than their food supply normally allows. 4 The first public presentation of Charles Darwin's theory of evolution by means of natural selection was done jointly with a presentation of the work of ___ , who independently derived essentially the same theory. a. Lamarck b. Bates c. Lyell d. Malthus e. Wallace{{ANS}}e. Wallace It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that a. island forms and mainland forms descended from common ancestors. b. the islands were originally part of the continent. c. island forms and mainland forms have identical gene pools. d. the island forms and mainland forms are converging. e. common environments are inhabited by the same organisms.{{ANS}}a. island forms and mainland forms descended from common ancestors. Which is of the following are commonly used to date fossils (especially those likely to be millions of years old)? a. their association with index fossils b. radioisotope dating of the fossils themselves c. their relative position in rock layers d. radioisotope dating of rock layers above and below the fossils{{ANS}}a, c, d The modern theory of plate tectonics is used in studies of a. vestigial structures b. biogeography c. mutations d. reproductive isolating mechanisms e. homologous features{{ANS}}b. biogeography Which of the following pieces of evidence most strongly supports the common origin of all life on Earth? a. All organisms reproduce. b. All organisms have undergone evolution. c. All organisms require energy. d. All organisms show heritable variation. e. All organisms use essentially the same genetic code.{{ANS}}e. All organisms use essentially the same genetic code. Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? a. Natural selection cannot account for losses, only for innovations. b. Natural selection accounts for these losses by the principle of use and disuse. c. The ancestors of these organisms experienced harmful mutations that forced them to find new habitats that these species had not previously used. d. Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.{{ANS}}d. Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. Which is most likely to happen to a human autosomal aneuploid? A. death around the age of 1 year B. survival until the mid-thirties C. survival until the early teens D. spontaneous abortion E. death around the age of 1 month{{ANS}}D. spontaneous abortion In humans, wet earwax is a dominant trait governed by normal Mendelian inheritance for a single autosomal gene with two possible alleles; the other trait, dry earwax, is recessive. A woman with wet earwax has one child, and that child has dry earwax. What is the genotype of the woman with respect to the wet/dry earwax gene? A. heterozygous B. homozygous recessive C. most likely homozygous dominant D. cannot be determined without more crosses{{ANS}}A. heterozygous In pea plants purple flower color is dominant over white flower color. A pea plant that is homozygous purple-flowered is crossed with another pea plant that is heterozygous. Which answer fits the predicted genotype(s) of their offspring with respect to flower color? A. all Aa B. all AA C. 1 Aa : 1 aa D. 1 AA : 2 Aa : 1 aa E. 1 AA : 1 Aa{{ANS}}E. 1 AA : 1 Aa In snapdragons, heterozygotes have pink flowers, whereas homozygotes have either red or white flowers. When a pink-flowered snapdragon is crossed with a pink-flowered snapdragon, what proportion of the offspring will have pink flowers? A. 50% B. 75% C. 0% D. 25% E. 100%{{ANS}}A. 50% A phylum is divided into ____ as the next taxonomic level. A. families B. orders C. species D. classes E. genera{{ANS}}D. classes The chromosome-level change depicted between the top and bottom in the figure above represents a(n) ________. A. duplication B. reciprocal translocation C. inversion D. deletion{{ANS}}C. inversion Examine the pedigree above, where individuals that have the genetic condition being tested are marked with filled squares or circles. Which of the following inheritance patterns is most likely correct for this condition? A. X-linked dominant B. autosomal recessive C. X-linked recessive D. autosomal dominant E. the pedigree does not indicate any known inheritance pattern{{ANS}}C. X-linked recessive Five dialysis bags, constructed from a semi-permeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag from was graphed. (Percent change was from the mass of the bag at time 0, the start of the experiment.) For which line or lines does the data indicate that the solution in the bag is isotonic compared to the solution in the beaker at the end of the experiment (60 minute timepoint)? A. A B. B C. C D. D E. E F. A and B G. A, C, and E H. D and E{{ANS}}G. A, C, and E The various species of Galapagos finches are closely related to each other genetically; their next closest genetic relatives are found: A. on the mainland of Europe B. on islands with a similar climate in the Atlantic Ocean C. on the nearby mainland of South America D. on islands with a similar climate near New Zealand{{ANS}}C. on the nearby mainland of South America When columbines with lavender flowers are mated they produce offspring that make either dark purple, lavender, or white flowers. The ratio is 1 dark purple: 2 lavender: 1 white. Based on this, inheritance of flower color in columbines is apparently an example of: A. pleiotropy. B. epistasis. C. gene interactions. D. multiple alleles. E. incomplete dominance.{{ANS}}E. incomplete dominance. You are genetic counselor, and a couple comes to you with concerns that if they have a child together it could have hemophilia. The man does not have hemophilia. The woman does not have X-linked hemophilia either, but her father does have it. Which of the following would be the most correct thing to tell them? A. none of their offspring should have hemophilia, but all of their female offspring will be carriers for hemophilia. B. all of their male offspring will have hemophilia, and each of their female offspring will have a 50% chance of having hemophilia. C. any child that they produce will have a 50% chance of having hemophilia. D. all of their male offspring will have hemophilia, and while their female offspring should not have hemophilia they will all be carriers. E. each of their male offspring will have a 50% chance of having hemophilia, and while their female offspring should not have hemophilia they will each have a 50% chance of being carriers.{{ANS}}E. each of their male offspring will have a 50% chance of having hemophilia, and while their female offspring should not have hemophilia they will each have a 50% chance of being carriers. Based on the phylogenetic tree below, which of the following presents the species most closely related to orang-utans (or the group of species that are equally the most closely related to orang-utans)? A. gorillas and chimpanzees B. gibbons, gorillas, chimpanzees, bonobos, and humans C. gibbons and gorillas D. gorillas, chimpanzees, bonobos, and humans E. gibbons{{ANS}}D. gorillas, chimpanzees, bonobos, and humans Which of the following is the most appropriate term to use for a structure that has lost most or all of its ancestral function in a given species but that is still present in some form in that species? An example of such a structure would be the appendix in humans. A. vestigial B. homoplastic C. homologous D. heterogeneous E. divergent{{ANS}}A. vestigial In his transformation experiments, Griffith observed that A. mice infected with a pathogenic strain of bacteria can spread the infection to other mice. B. mutant mice were resistant to bacterial infections. C. mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain nonpathogenic. D. mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form. E. infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains.{{ANS}}D. mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form. In the metabolic pathway indicated above, a mutation results in a defective enzyme B. Which of the following would be a consequence of that mutation? A. an accumulation of B and little or no production of C B. an accumulation of A and little or no production of B and C C. an accumulation of C and little or no production of B D. an accumulation of B and C E. an accumulation of C{{ANS}}A. an accumulation of B and little or no production of C