Bio 101 Homework #3 Prof. Fournier 1. The principles of dominance, segregation, and independent assortment were first described by A) Watson B) Linnaeus C) Mendel D) Morgan 2. After observing the offspring of many generations of pea plant crosses, Gregor Mendel formulated the principle of A) dominance B) polyploidy C) crossing-over D) mutation 3. A child has brown hair and brown eyes. His father has brown hair and blue eyes. His mother has red hair and brown eyes. Which statement best explains why the child has brown hair and brown eyes? A) a gene mutation occurred that resulted in brown hair and brown eyes B) gene expression must change in each generation so evolution can occur C) the child received genetic information from each parent D) cells from his mother's eyes were present in the fertilized egg 4. Base your answer to the following question on the pedigree chart below, which shows a history of ear lobe shape, and on your knowledge of biology. The genotype of individual 1 could be A) EE, only B) Ee, only C) ee D) EE or Ee 5. A cross between two mice with long tails and brown fur produced the four types of offspring listed below: long tailed with brown fur long tailed with white fur short tailed with brown fur short tailed with white fur Which genetic mechanism best explains the results of this cross? A) intermediate inheritance B) gene linkage C) independent assortment D) crossing-over 6. F represents the gene for brown coat color and f represents the gene for white coat color. In the cross FF x ff all the offspring have a brown coat. Which genetic principle is illustrated by this cross? A) crossing-over B) multiple alleles C) codominance D) dominance 7. In canaries, the gene for singing (S) is dominant over the gene for non-singing (s). When hybrid singing canaries are mated with non-singing canaries, what percentage of the offspring is likely to possess the singing trait? A) 0% B) 25% C) 50% D) 100% 8. In squirrels, the gene for gray fur (G) is dominant over the gene for black fur (g). If 50% of a large litter of squirrels are gray, the parental cross that produced this litter was most likely A) GG Gg B) GO GO C) Gg gg D) gg gg 9. In dogs, wire hair (D) is dominant over smooth hair (d). If two wire-haired dogs produce a smooth-haired pup, the genotypes of the parent dogs are most likely A) DD anddd B) Dd and Dd C) DD and DD D) Dd and dd
10. The gene for tallness (T) is dominant over the gene for shortness (t) in pea plants. A homozygous dominant pea plant is crossed with a heterozygous pea plant, and 200 seeds are produced. Approximately how many of these seeds can be expected to produce plants that are homozygous dominant? 16. Which process is illustrated by the diagram below? A) 0 B) 50 C) 100 D) 200 11. In pea plants, the trait for tall stems is dominant over the trait for short stems. If two heterozygous tall plants are crossed, what percentage of the offspring would be expected to have the same phenotype as the parents? A) 25% B) 50% C) 75% D) 100% 12. The chart below indicates a method of representing traits in pea plants. A) crossing-over B) nondisjunction C) sex determination D) independent assortment 17. One disadvantage of a genetic mutation in a human skin cell is that it A) may result in the production of a defective protein B) may alter the sequence of simple sugars in insulin molecules C) can lead to a lower mutation rate in the off-spring of the human D) can alter the rate of all the metabolic processes in the human 18. Base your answer to the following question on Molecule 1 represents a segment of hereditary information, and molecule 2 represents the portion of a molecule that is determined by information from molecule 1. Some offspring of a cross in pea plants were tall and green. According to the chart, these plants could be represented by A) TTYY B) Ttyy C) ttyy D) TtYy 13. In pea plants, the gene for yellow seeds is dominant over the gene for green seeds. Which procedure can be used to determine if a plant that produces yellow seeds is homozygous or heterozygous? A) crossing it with plants that are homozygous for yellow seeds B) crossing it with plants that are homozygous for green seeds C) crossing it with plants that are known to contain mutant genes D) exposing it to high doses of radiation 14. Which statement best describes a human chromosome? A) It is made of amino acid subunits that form genes. B) It contains genes that may code for the production of enzymes. C) It is normally passed to the next generation through a placenta. D) It varies in function from one generation to the next. 15. Hereditary information for most traits is generally located in A) genes found on chromosomes B) chromosomes found on genes C) the mitochondria of gametes D) the lysosomes in the cytoplasm What will most likely happen if there is a change in the first three subunits on the upper strand of molecule 1? A) The remaining subunits in molecule 1 will also change. B) A portion of molecule 2 may be different. C) Molecule 1 will split apart, triggering an immune response. D) Molecule 2 may form two strands rather than one. 19. Which illustration of a chromosomal change best represents a chromosome mutation known as a deletion? A) B) C) D) 20. Although genetic mutations may occur spontaneously in organisms, the incidence of such mutations may be increased by A) radioactive substances in the environment B) lack of vitamins in the diet C) a long exposure to humid climates D) a short exposure to freezing temperatures
21. X-rays, formaldehyde, and asbestos fibers are all similar in that they are A) animal preservatives B) used to treat diseases C) used to diagnose diseases D) mutagenic agents 22. Overexposure of animals to x-rays is dangerous because x-rays are known to damage DNA. A direct result of this damage is cells with A) unusually thick cell walls B) no organelles in the cytoplasm C) abnormally large chloroplasts D) changes in chromosome number or structure 23. A mutation occurs in the liver cells of a certain field mouse. Which statement concerning the spread of this mutation through the mouse population is correct? A) It will spread because it is beneficial. B) It will spread because it is a dominant gene. C) It will not spread because it is not in a sex cell. D) It will not spread because it is a recessive gene. 24. As a result of sexual reproduction, an organism can pass a gene mutation to its offspring if the mutation occurs in A) a body cell B) a gamete C) liver tissue D) white blood cells 25. Base your answer to the following question on the diagram of paired homologous chromosomes shown below and on your knowledge of biology. 27. Which term best describes genes carried only on the X- chromosome? A) hybrid B) codominant C) autosomal D) sex-linked Which technique was used to organize the chromosomes as shown in the diagram? A) screening B) chromatography C) karyotyping D) grafting 26. The technique known as karyotyping is used to detect abnormalities in A) chromosomes B) ribosomes C) blood and urine D) amniotic fluid
28. Four different segments of a DNA molecule are represented below. There is an error in the DNA molecule in A) segment 1, only B) segment 3, only C) segments 2 and 3 D) segments 2 and 4 29. The diagram below represents an incomplete section of a DNA molecule. The boxes represent unidentified bases. 32. Base your answer to the following question on the diagram below and on your knowledge of biology. The diagram represents molecules involved in protein synthesis. When the boxes are filled in, what will the total number of bases represented by the letter A (both inside and outside the boxes) be? A) 1 B) 2 C) 3 D) 4 30. A portion of a molecule is shown in the diagram below. In plant cells, molecule 1 is found in the Which statement best describes the main function of this type of molecule? A) It is a structural part of the cell wall. B) It stores energy for metabolic processes. C) It determines what traits may be inherited. D) It transports materials across the cell membrane. 31. A DNA nucleotide may contain A) deoxyribose, cytosine, and a lipid B) deoxyribose, thymine, and a phosphate group C) ribose, uracil, and a polypeptide D) ribose, adenine, and thymine A) centriole B) nucleus C) cell wall D) lysosome 33. Which molecule has the shape of a double-stranded helix? A) RNA B) DNA C) ADP D) ATP 34. When DNA separates into two strands, the DNA would most likely be directly involved in A) replication B) fertilization C) differentiation D) evolution 35. In the synthesis of proteins, what is the function of messenger-rna molecules? A) They act as a template for the synthesis of DNA. B) They carry information that determines the sequence of amino acids. C) They remove amino acids from the nucleus. D) They carry specific enzymes for dehydration synthesis. 36. If a portion of a messenger RNA molecule contains the base sequence A-A-U, the corresponding transfer RNA base sequence is A) A-A-U B) G-G-T C) T-T-C D) U-U-A
37. Base your answer to the following question on the diagram below of a biochemical process and on your knowledge of biology. Which amino acid would be transferred to the position of codon CAC? A) leucine B) glycine C) valine D) histidine 38. DNA serves as a template for the synthesis of A) messenger RNA B) cellulose C) starches D) lipids 39. Which statement best describes messenger RNA? A) It transfers polypeptides to the nucleus. B) It is chemically more complex than DNA. C) It has one oxygen atom less than DNA. D) It is composed of a single strand of nucleotides. 40. Which statement best describes the relationship between cells, DNA, and proteins? A) Cells contain DNA that controls the production of proteins. B) DNA is composed of proteins that carry coded information for how cells function. C) Proteins are used to produce cells that link amino acids together into DNA. D) Cells are linked together by proteins to make different kinds of DNA molecules. 41. A change in the order of DNA bases that code for a respiratory protein will most likely cause A) the production of a starch that has a similar function B) the digestion of the altered gene by enzymes C) a change in the sequence of amino acids determined by the gene D) the release of antibodies by certain cells to correct the error 42. Base your answer to the following question on the chart below and on your knowledge of biology. Which base sequence of a DNA molecule produces a codon on an mrna molecule that will allow the amino acid arginine to be incorporated into a protein? A) C G A B) G C T C) C G U D) G C U
43. Base your answer to the following question on the diagram below and on your knowledge of biology. The diagram represents a step in protein synthesis. If a sequence of nitrogenous bases on DNA strand I is T-A-G-C-C-T-A, the corresponding sequence on the RNA will be A) A-T-C-G-G-A-T B) A-U-C-G-G-A-U C) T-A-G-C-C-T-A D) U-T-C-G-G-U-T 44. Amino acid molecules are bonded together in a specific sequence on cell structures known as A) ribosomes B) vacuoles C) mitochondria D) centromeres 45. The pedigree of Seattle Slew, a racehorse considered by some to be one of the fastest horses that ever lived, includes very fast horses on both his mother's side and his father's side. Seattle Slew most likely was a result of A) environmental selection B) alteration of DNA molecules C) selective breeding D) a sudden mutation
46. The diagram below represents a genetic procedure. Which statement best describes the outcome of this procedure? A) Bacterial cells will destroy defective human genetic material. B) Bacterial cells may form a multicellular embryo. C) The inserted human DNA will change harmful bacteria to harmless ones. D) The inserted human DNA may direct the synthesis of human proteins. 47. The flounder is a species of fish that can live in very cold water. The fish produces an "antifreeze" protein that prevents ice crystals from forming in its blood. The DNA for this protein has been identified. An enzyme is used to cut and remove this section of flounder DNA that is then spliced into the DNA of a strawberry plant. As a result, the plant can now produce a protein that makes it more resistant to the damaging effects of frost. What is this process known as? A) sorting of genes B) genetic engineering C) recombination of chromosomes D) mutation by deletion of genetic material 48. Researchers Cohn and Boyer transferred a gene from an African clawed frog into a bacterium. To accomplish this, these scientists had to use A) enzymes to cut out and insert the gene B) hereditary information located in amino acids C) radiation to increase the gene mutation rate of the bacterial cells D) cancer cells to promote rapid cell division
49. The diagram below represents the cloning of a carrot plant. Compared to each cell of the original carrot plant, each cell of the new plant will have A) the same number of chromosomes and the same types of genes B) the same number of chromosomes, but different types of genes C) half the number of chromosomes and the same types of genes D) half the number of chromosomes, but different types of genes 50. The nucleus is removed from a body cell of one organism and is placed in an egg cell that has had its nucleus removed. This process, which results in the production of organisms that are genetically alike, is known as A) cloning B) fertilization C) biological adaptation D) DNA production 51. The diagram below represents division of a cell that produces two daughter cells. Which statement most likely describes the daughter cells produced? A) The daughter cells will pass on only half of the genetic information they received from the original cell. B) The daughter cells will each produce offspring that will have the same genetic information as the original cell. C) The daughter cells will each undergo the same mutations as the original cell after reproduction has occurred. D) The daughter cells will not pass on any of the genes that they received from the original cell. 52. Asexual reproduction primarily involves the process of 53. Base your answer to the following question on The diagrams below A) ovulation B) pollination represent a cell process. C) mitosis D) spermatogenesis If the cell in diagram 1 contains 4 chromosomes, what is the total number of chromosomes in each cell in diagram 3? A) 8 B) 2 C) 16 D) 4
54. Which statement correctly describes mitotic cell division? A) The chromosome number in the daughter cells is reduced by half. B) The fusion of nuclei restores the diploid number. C) Two cellular divisions result in the production of four monoploid cells. D) Chromosomes are replicated and two identical daughter nuclei are formed. 55. Which diagram best represents mitotic cell division? A) B) C) D) 56. A cell in the stem tip of a corn plant contains 20 chromosomes. After this cell divides, how many chromosomes should each resulting daughter cell contain? A) 10 B) 20 C) 30 D) 40 57. Which is the correct sequence for the stages of mitotic cell division represented by the diagrams below? 60. Which row in the chart below indicates the correct process for each event indicated? A) 1 B) 2 C) 3 D) 4 61. Which two structures of a frog would most likely have the same chromosome number? A) skin cell and fertilized egg cell B) zygote and sperm cell C) kidney cell and egg cell D) liver cell and sperm cell 62. Which row in the chart below best describes asexual reproduction? A) A B C D B) A C D B C) B A D C D) B C D A 58. Uncontrolled cell division is a characteristic of A) cleavage B) oogenesis C) cancer D) regeneration 59. In animals, sexual reproduction involves which activity? A) binary fission B) vegetative propagation C) meiotic cell division D) spore formation A) 1 B) 2 C) 3 D) 4 63. How do human cells resulting from meiotic division differ from human cells resulting from mitotic division? A) they have twice as many chromosomes B) they have the same number of chromosomes C) they have one-half the number of chromosomes D) they have one-quarter as many chromosomes 64. Compared to the number of chromosomes contained in a body cell of a parent, how many chromosomes would normally be contained in a gamete? A) the same number B) twice as many C) one-fourth as many D) half as many 65. The chromosome number of a cell produced by mitotic cell division is represented by 2n. If that cell had been produced by meiotic cell division, its chromosome number would be represented by A) n 2 B) n C) 2n D) 4n
66. Most cells in the body of a fruit fly contain eight chromosomes. How many of these chromosomes were contributed by each parent of the fruit fly? A) 8 B) 2 C) 16 D) 4 Base your answers to questions 67 through 69 on the information and chart below and on your knowledge of biology. In DNA, a sequence of three bases is a code for the placement of a certain amino acid in a protein chain. The table below shows some amino acids with their abbreviations and DNA codes. 67. Describe how a protein would be changed if a base sequence mutates from GGA to TGA. 68. Identify one environmental factor that could cause a base sequence in DNA to be changed to a different base sequence. 69. Which amino acid chain would be produced by the DNA base sequence below? C-A-A-G-T-T-A-A-A-T-T-A-T-T-G-T-G-A A) B) C) D) 70. Base your answer to the following question on the statement below and on your knowledge of biology. Selective breeding has been used to improve the racing ability of horses. Define selective breeding and state how it would be used to improve the racing ability of horses. Base your answers to questions 71 through 73 on the table below, which represents the DNA codes for several amino acids. 72. The DNA sequence undergoes the following change: TACACACAAACGGGG TACACCCAAACGGGG How would the sequence of amino acids be changed as a result of this mutation? 73. A certain DNA strand has the base sequence: TACACACAAACGGGG. In the space provided below, write the sequence of amino acids synthesized from this code if it is read from left to right. 71. The original DNA sequence undergoes the following change: TACACACAAACGGGG TACACACAAACGGGT State one reason this mutation produces no change in the action of the final molecule that will be synthesized from this code.
74. Scientists have successfully cloned sheep and cattle for several years. A farmer is considering the advantages and disadvantages of having a flock of sheep cloned from a single individual. Discuss the issues the farmer should take into account before making a decision. Your response should include: how a cloned flock would be different from a noncloned flock one advantage of having a cloned flock one disadvantage of having a cloned flock one reason that the farmer could not mate these cloned sheep with each other to increase the size of his flock one reason that the offspring resulting from breeding these sheep with an unrelated sheep would not all be the same
Answer Key Homework 3A 1. C 2. A 3. C 4. D 5. C 6. D 7. C 8. C 9. B 10. C 11. B 12. B 13. B 14. B 15. A 16. A 17. A 18. B 19. A 20. A 21. D 22. D 23. C 24. B 25. C 26. A 27. D 28. B 29. C 30. C 31. B 32. B 33. B 34. A 35. B 36. D 37. D 38. A 39. D 40. A 41. C 42. B 43. B 44. A 45. C 46. D 47. B 48. A 49. A 50. A 51. B 52. C 53. D 54. D 55. A 56. B 57. B 58. C 59. C 60. D 61. A 62. A 63. C 64. D 65. B 66. D 67. Examples: The shape of the protein may be changed. The amino acid sequence would be different. The protein would contain threonine instead of proline. The protein being synthesized may not work correctly. The protein will not be able to function. 68. Examples: ultraviolet light radiation X rays chemicals 69. C 70. Choose parents with the desired trait to breed. A fast male horse is bred to a fast female horse and the offspring may inherit the fast-running traits of both parents. 71. GGG and GGT both code for proline The same molecule will be produced. The last three bases still code for proline. The same amino acid sequence is produced. 72. methionine tryptophan valine cysteine proline -- or-- the first cysteine would be replaced by tryptophan. 73. methionine cysteine valine cysteine proline 74. (essay)
Answer Key Homework 3A 74. Acceptable responses include, but are not limited to: There would be no variation. All would be identical genetic copies, unlike noncloned herds, where much genetic diversity would be present. All sheep would be the same. Acceptable responses include, but are not limited to: All sheep would have one or more desired traits (that the original individual possessed). Acceptable responses include, but are not limited to: Since all are the same, the entire flock could be lost if a disease to which they have no resistance were to infect them. The sheep may have a genetic flaw. shorter life span They would all be the same sex, so they could not mate with each other. Acceptable responses include, but are not limited to: Both parents contribute genes to the offspring. Different gene combinations will result.