Name: Date: 1. Which statement best describes the relationship between the number of genes and the number of chromosomes in human skin cells? 2. Base your answer(s) to the following question(s) on the diagram below of a DNA molecule and on lyour knowledge of biology. (1) There are more genes than chromosomes in skin cells. (2) There are more chromosomes than genes in skin cells. (3) There are equal numbers of genes and chromosomes in skin cells. What occurs in the process of replication? (1) Structure 1 is hydrolyed. (2) Chemical bonds are broken in region 2. (3) Structure 3 is synthesized. (4) Proteins are formed in region 2. page 1
3. A great deal of information can now be obtained about the future health of people by examining the genetic makeup of their cells. There are concerns that this information could be used to deny an individual health insurance or employment. These concerns best illustrate that 5. In an experiment, DNA from dead pathogenic bacteria was transferred into living bacteria that do not cause disease. These altered bacteria were then injected into healthy mice. These mice died of the same disease caused by the original pathogens. Based on this information, which statement would be a valid conclusion? (1) scientific explanations depend upon evidence collected from a single source (2) scientific inquiry involves the collection of information from a large number of sources (3) acquiring too much knowledge in human genetics will discourage future research in that area (4) while science provides knowledge, values are essential to making ethical decisions using this knowledge (1) DNA is present only in living organisms. (2) DNA functions only in the original organism of which it was a part. (3) DNA changes the organism receiving the injection into the original organism. (4) DNA from a dead organism can become active in another organism. 4. When DNA separates into two strands, the DNA would most likely be directly involved in (1) replication (2) fertilization (3) differentiation (4) evolution 6. If a set of instructions that determines all of the characteristics of an organism is compared to a book, and a chromosome is compared to a chapter in the book, then what might be compared to a paragraph in the book? (1) a starch molecule (2) an egg (3) an amino acid (4) a DNA molecule page 2
7. The diagram below represents a section of a molecule that carries genetic information. The pattern of numbers represents (1) a sequence of paired bases (2) the order of proteins in a gene (3) folds of an amino acid 8. Base your answer(s) to the following question(s) on the information and diagram below and on your knowledge of biology. The diagram below shows the results of a test that was done using DNA samples from three bears of different species. Each DNA sample was cut into fragments using a specific enzyme and placed in the wells as indicated below. The DNA fragments were then separated using gel electrophoresis. (4) positions of gene mutations Gel electrophoresis is used to separate DNA fragments on the basis of their (1) size (2) color (3) functions (4) chromosomes page 3
9. Base your answer(s) to the following question(s) on the information and diagram below and on your knowledge of biology. The four wells represented in the diagram were each injected with fragments that were prepared from DNA samples using identical techniques. 10. Steps in a reproductive process used to produce a sheep with certain traits are listed below. Step 1 The nucleus was removed from an unfertilized egg taken from sheep A. Step 2 The nucleus of a body cell taken from sheep B was then inserted into this unfertilized egg from sheep A. Step 3 The resulting cell was then implanted into the uterus of sheep C. Step 4 Sheep C gave birth to sheep D. Which sheep would be most genetically similar to sheep D? This laboratory procedure is known as (1) cloning (2) gel electrophoresis (3) chromatography (1) sheep A, only (2) sheep B, only (3) both sheep A and B (4) both sheep A and C (4) use of a dichotomous key 11. Which two structures of a frog would most likely have the same chromosome number? (1) skin cell and fertilized egg cell (2) zygote and sperm cell (3) kidney cell and egg cell (4) liver cell and sperm cell page 4
12. Base your answer(s) to the following question(s) on the diagram below and on your knowledge of biology. The diagram shows the results of a technique used to analyze DNA. 13. Electrophoresis is a method of (1) separating DNA fragments (2) changing the genetic code of an organism (3) indicating the presence of starch (4) separating colored compounds on a strip of paper This technique used to analyze DNA directly results in (1) synthesizing large fragments of DNA (2) separating DNA fragments on the basis of size (3) producing genetically engineered DNA molecules (4) removing the larger DNA fragments from the samples 14. Chromosomes can be described as (1) large molecules that have only one function (2) folded chains of bonded glucose molecules (3) reproductive cells composed of molecular bases (4) coiled strands of genetic material page 5
15. Several structures are labeled in the diagram of a puppy shown below. 17. The diagram below represents the banding pattern for human chromosome 11, with some of the bands labeled. Every cell in each of these structures contains (1) equal amounts of ATP (2) identical genetic information (3) proteins that are all identical The bands represent (1) proteins (2) genes (3) starches (4) enzymes (4) organelles for the synthesis of glucose 16. Coded instructions that are passed from one generation to the next can be most directly changed by the processes of (1) passive transport, natural selection, and synthesis (2) selective breeding, replication, and absorption (3) recombination, mutation, and genetic engineering (4) evolution, reproduction, and digestion 18. Modern technology could be used to clone pet dogs and cats. The cloned animals would resemble the original pets because (1) the genes of the new animals are different from those of the original pets (2) half of the genetic information of the new animals is the same as that of the original pets (3) the new animals have mutations not found in the original pets (4) the new animals have the same genetic information as the original pets page 6
19. The colors and scents of plants attract helpful insects and repel insects that feed on them. The production of the proteins that provide these colors and scents is the direct result of the (1) behavior learned from parent plants (2) presence of specific genes (3) the genetic makeup of the surrounding vegetation 21. Which technique could be used to determine the relative number of bases in fragments taken from a sample of DNA? (1) electrophoresis (2) cloning (3) paper chromatography (4) light microscopy (4) inability of plants to move as animals do 20. Which organism would most likely have new gene combinations? (1) a frog that was produced from a skin cell of a frog (2) a hamster resulting from sexual reproduction (3) a bacterium resulting from asexual reproduction (4) a starfish that grew from part of a starfish 22. When the bacterium Serratia marcescens is grown on a sterile culture medium in a petri dish at 30 C, the bacterial colonies are cream colored. When this same bacterium is cultured under identical conditions, except at a temperature of 25 C, the colonies are brick red. This difference in color is most likely due to the (1) type of nutrients in the culture medium (2) sterilization of the culture medium (3) effect of temperature on the expression of the gene for color (4) effect of colony size on the synthesis of color pigments page 7
23. Base your answer to the following question on the graph below and on your knowledge of biology. The graph shows the level of gene expression of five different genes in normal and cancerous cells. 24. Several goldfish were kept in a small aquarium for several years. The fish grew to be approximately 6 centimeters long in the first year, and after that, growth in length stopped. These fish were later transferred to a large pond. In the pond, the goldfish grew much larger, reaching lengths of around 25 centimeters. Which statement provides the best explanation for the increased growth of the fish in the pond? (1) Chemicals present in the pond increased the amount of DNA in the fish, causing the growth increase. Which statement is a valid inference that can be made based on the data in this graph? (1) The change in the level of gene expression in gene 4 could indicate it plays a major role in the development of cancer. (2) Slight decreases in gene expression will always result in the formation of cancer cells. (2) The expression of genetic information in the fish was influenced by their surroundings. (3) The fish expressed and passed on only those characteristics that enabled them to survive in the new environment. (4) The size of the fish depended only on their food supply and not on their DNA. (3) Cells will develop cancer if the gene expression of these five genes remains below four peptides per second. (4) An increase in the level of gene expression in these five genes is necessary for cancer to develop in cells. page 8
25. The table below indicates a reproductive pattern in some sea turtles when eggs develop in areas with differing temperatures. Sex Determination in Sea Turtles Temperature ( C) below 23 Offspring Produced usually none 23 27 mostly males 28 30 50/50 males: females 31 33 mostly females above 33 usually none The sex of turtle offspring is most probably (1) determined only by genes inherited from the parent turtles 26. In the summer, the arctic fox appears brown because its cells produce a dark pigment. However, in the winter, the arctic fox appears white because the dark pigment is not produced. The color change is most likely due to the effect of (1) different genes produced in the different seasons (2) increased pollution on genetic mutations (3) environmental conditions on gene expression (4) poor nutrition on cell growth and development (2) controlled entirely by the location where the young are raised (3) a result of genetic information being influenced by environmental conditions (4) an identical pattern to the reproductive pattern found in humans 27. Even though identical twins have the same genetic material, they may develop slightly different characteristics because (1) each twin receives different chromosomes from the egg (2) one twin may only have genes from the father (3) gene expression may be influenced by factors that switch genes on and off (4) a gene mutation may have occurred before the zygote divided page 9
28. The puppies shown in the photograph below are all from the same litter. The differences seen within this group of puppies are most likely due to (1) overproduction and selective breeding (2) mutations and elimination of genes (3) evolution and asexual reproduction (4) sorting and recombination of genes page 10
29. Which sequence best represents the relationship between DNA and the traits of an organism? (1) (2) (3) (4) page 11
30. The letters in the accompanying diagram represent genes on a particular chromosome. 31. To determine the identity of their biological parents, adopted children sometimes request DNA tests. These tests involve comparing DNA samples from the child to DNA samples taken from the likely parents. Possible relationships may be determined from these tests because the (1) base sequence of the father determines the base sequence of the offspring Gene B contains the code for an enzyme that cannot be synthesized unless gene A is also active. Which statement best explains why this can occur? (1) A hereditary trait can be determined by more than one gene. (2) DNA of parents and their offspring is more similar than the DNA of nonfamily members (3) position of the genes on each chromosome is unique to each family (4) mutation rate is the same in closely related individuals (2) Genes are made up of double-stranded segments of DNA. (3) All the genes on a chromosome act to produce a single trait. (4) The first gene on each chromosome controls all the other genes on the chromosome. page 12
32. Researchers recently discovered that when hammerhead sharks were moved to shallower water, resulting in exposure to increased light intensity, their backs turned a deep brownish black. Which statement best supports this observation? 34. The fruit fly represented in the diagram below has unusual, curled wings that formed after exposure to radiation. (1) Genes are inherited, but their expression can be modified by interactions with the environment. (2) The cells of hammerhead sharks contain many thousands of different genes in their nuclei. (3) An inherited trait of an individual can be determined by one or by many genes. (4) Asexually produced offspring are normally genetically identical to the parent. In order for the fly to pass this trait on to its offspring, a change had to occur in (1) the blood cells of the fly (2) the gametes of the fly (3) all the body cells of the fly (4) the muscles of the fly 33. Brothers and sisters often have similar facial characteristics, such as nose shape or eye color, because they 35. Which factor has the greatest influence on the development of new, inheritable characteristics? (1) are raised in similar environments (2) eat similar types of foods (3) have similar types of proteins (4) use similar types of facial care products (1) combinations of genes resulting from mitosis (2) mutations of genes in reproductive cells (3) sorting of genes during asexual reproduction (4) recombining of genes during differentiation page 13
36. Many years ago, a scientist grew pea plants that produced wrinkled peas. The peas from these plants produced new plants that also produced wrinkled peas. The scientist concluded that something in the parent plants was being transmitted to the next generation. This discovery is now known as (1) genetic engineering (2) biological evolution (3) heredity (4) natural selection 38. 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 (1) the same number of chromosomes and the same types of genes (2) the same number of chromosomes, but different types of genes (3) half the number of chromosomes and the same types of genes (4) half the number of chromosomes, but different types of genes 37. Young birds that have been raised in isolation from members of their species build nests characteristic of their species. This suggests that the nest-building behavior is (1) genetically inherited from parents (2) learned by watching members of their species (3) a disadvantage to the survival of the species (4) a direct result of the type of food the bird eats 39. The transfer of genes from parents to their offspring is known as (1) differentiation (2) heredity (3) immunity (4) evolution page 14
40. Asexually reproducing organisms pass on hereditary information as 42. A portion of a molecule is shown in the diagram below. (1) sequences of A, T, C, and G (2) chains of complex amino acids (3) folded protein molecules (4) simple inorganic sugars Which statement best describes the main function of this type of molecule? (1) It is a structural part of the cell wall. (2) It stores energy for metabolic processes. (3) It determines what traits may be inherited. (4) It transports materials across the cell membrane. 41. Hereditary traits are transmitted from generation to generation by means of (1) specific sequences of bases in DNA in reproductive cells (2) proteins in body cells (3) carbohydrates in body cells (4) specific starches making up DNA in reproductive cells page 15
43. Base your answer(s) to the following question(s) on the diagram below of a DNA molecule and on lyour knowledge of biology. 44. A medical test indicates that a patient has a defective protein. This condition is most likely due to a change in the directions coded in the (1) number of hydrogen atoms in starch molecules (2) sequence of inorganic molecules (3) number of carbon atoms in sugar molecules (4) sequence of subunits in DNA What is the base sequence of strand X? (1) G-T-A-C (2) T-G-C-A (3) G-T-C-A (4) A-T-C-G 45. A small amount of DNA was taken from a fossil of a mammoth found frozen in glacial ice. Genetic technology can be used to produce a large quantity of identical DNA from this mammoth s DNA. In this technology, the original DNA sample is used to (1) stimulate differentiation in other mammoth cells (2) provide fragments to replace certain human body chemicals (3) act as a template for repeated replication (4) trigger mitosis to obtain new base sequences page 16
46. The accompanying diagrams represent portions of the genes that code for wing structure in two organisms of the same species. Gene 1 was taken from the cells of a female with normal wings, and gene 2 was taken from the cells of a female with abnormal wings. 47. 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. The abnormal wing structure was most likely due to (1) an insertion (2) a substitution (3) a deletion (4) normal replication What will most likely happen if there is a change in the first three subunits on the upper strand of molecule 1? (1) The remaining subunits in molecule 1 will also change. (2) A portion of molecule 2 may be different. (3) Molecule 1 will split apart, triggering an immune response. (4) Molecule 2 may form two strands rather than one. page 17
48. In the accompanying diagram, strands I and II represent portions of a DNA molecule. Strand II would normally include 50. Base your answer(s) to the following question(s) 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 (1) AGC (2) TCG (3) TAC (4) GAT 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 (1) (2) (3) 49. The genetic code of a DNA molecule is determined by a specific sequence of (4) (1) ATP molecules (2) sugar molecules (3) chemical bonds (4) molecular bases page 18
51. A single gene mutation results from (1) a change in a base sequence in DNA (2) recombination of traits (3) the failure of chromosomes to separate 53. The parents of a new baby believe they brought the wrong child home from the hospital. Gel electrophoresis was performed using DNA samples from the parents and the child. A section of the gel electrophoresis results is shown below. (4) blocked nerve messages Which conclusion is valid based on the gel electrophoresis results? 52. Genes involved in the production of abnormal red blood cells have an abnormal sequence of (1) ATP molecules (2) amino acids (3) sugars (4) bases (1) They have the correct child, because her genetic information is identical to that of the father. (2) They have the wrong child, because her genetic information does not match that of either parent. (3) They have the correct child, because her genetic information came from both parents. (4) They have the wrong child, because her genetic information matches only that of the mother. page 19
54. The diagram below shows an alteration that occurred during the replication process of a portion of a gene. The numbers identify the locations of specific bases in the sequence. Replication This alteration is most likely the result of 56. DNA samples can be separated according to size using the technique of (1) chromatography (2) electrophoresis (3) replication (4) dissection (1) a substitution at base 2 (2) a deletion of base 2 (3) an insertion of base 3 (4) a deletion of base 4 57. Four different segments of a DNA molecule are represented below. 55. The diagram below represents a segment of a gene on two chromosomes. Normal gene Mutated gene The change in the gene sequence is an example of There is an error in the DNA molecule in (1) segment 1, only (2) segment 3, only (3) segments 2 and 3 (4) segments 2 and 4 (1) an insertion (2) a deletion (3) a substitution (4) a replication page 20
58. The diagram below represents a portion of a DNA molecule. 59. Part of a molecule found in cells is represented below. Which process is most directly affected by the arrangement of components 1 through 4? (1) diffusion through cell membranes (2) fertilization of a sex cell (3) sequencing of amino acids in cells The letters represent different types of (4) increasing the number of cells in an organism (1) sugar molecules (2) molecular bases (3) enzymes (4) proteins 60. If 15% of a DNA sample is made up of thymine, T, what percentage of the sample is made up of cytosine, C? (1) 15% (2) 35% (3) 70% (4) 85% page 21
61. DNA electrophoresis is used to study evolutionary relationships of species. The diagram below shows the results of DNA electrophoresis for four different animal species. 62. The function of the coded instructions contained in the body cells of an organism is to (1) form a variety of gametes that will pass on hereditary information (2) direct the synthesis of proteins necessary for proper cell function (3) synthesize different kinds of amino acids in a specific sequence (4) produce the inorganic molecules needed for normal cell growth Which species has the most DNA in common with species A? (1) X and Y, only (2) Y, only (3) Z, only (4) X, Y, and Z page 22
63. The accompanying diagram represents a process that occurs within a cell in the human pancreas. 64. A change in the order of DNA bases that code for a respiratory protein will most likely cause (1) the production of a starch that has a similar function (2) the digestion of the altered gene by enzymes (3) a change in the sequence of amino acids determined by the gene (4) the release of antibodies by certain cells to correct the error This process is known as (1) digestion by enzymes (2) protein synthesis (3) energy production (4) replication of DNA 65. The diagram below shows some of the steps in protein synthesis. The section of DNA being used to make the strand of mrna is known as a (1) carbohydrate (2) gene (3) ribosome (4) chromosome page 23
66. Which row in the chart below contains a cell structure paired with its primary function? Row Cell Structure Function (1) ribosome protein synthesis (2) vacuole production of genetic information (3) nucleus carbohydrate synthesis (4) mitochondrion waste disposal (1) (1) (2) (2) (3) (3) (4) (4) 68. Which process is a common practice that has been used by farmers for hundreds of years to develop new plant and animal varieties? (1) cloning (2) genetic engineering (3) cutting DNA and removing segments (4) selective breeding for desirable traits 67. White short-horned cattle and Black Angus cattle have been crossed to produce offspring with superior beef and rapid growth qualities. This process of choosing organisms with the most desirable traits for mating is known as (1) cloning (2) biodiversity (3) selective breeding (4) genetic engineering page 24
69. Modern dogs are direct descendants of the gray wolf. They first appeared about 130,000 years ago. Today, there are about 150 different breeds of domestic dog, a few of which are shown below. 70. Scientists have cloned sheep but have not yet cloned a human. The best explanation for this situation is that (1) the technology to clone humans has not been explored (2) human reproduction is very different from that of other mammals (3) there are many ethical problems involved in cloning humans (4) cloning humans would take too long All modern domestic dogs are descendants of the gray wolf. adapted from: www.pbs.org The great variety of modern dogs can best be explained by (1) selective breeding of dogs over many years (2) the cloning of domestic dogs (3) genetic alterations in gray wolves alive today (4) natural selection favoring wolves over dogs 71. Scientists have successfully cloned animals, including large mammals such as sheep. Which statement provides the most likely reason that a human has not yet been cloned? (1) Humans have DNA that is structurally very different from other mammals. (2) Cloning can only be performed on animals that normally reproduce asexually. (3) Human genes are made of too many different types of simple sugars. (4) Some people consider human genetic experiments unethical. page 25
72. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. Female mosquitoes spread diseases when they bite humans to obtain blood. It is only the females that do the biting. Research is being conducted to alter the DNA of male mosquitoes. These altered males could then mate with normal female mosquitoes. All of the resulting female offspring would have wing defects that prevent them from flying. The method used to alter the male mosquitoes is an example of an application of (1) a feedback mechanism 73. Base your answer(s) to the following qusetion(s) on the statement below and on your knowledge of biology. Scientists have found a gene in the DNA of a certain plant that could be the key to increasing the amount of lycopene, a cancerfighting substance, in tomatoes. The process of inserting this gene into the DNA of a tomato plant is known as (1) selective breeding (2) genetic engineering (3) cloning (4) replication (2) selective breeding (3) biotechnology (4) physiology 74. A scientist claimed that he had cloned a guinea pig to produce two offspring, a male and a female. The claim is not valid because (1) guinea pigs can reproduce both sexually and asexually (2) the two offspring are not identical copies of the original guinea pig (3) each of the offspring had half the genetic information of the original guinea pig (4) none of the genetic information came from the original guinea pig page 26
75. Some goats have been genetically modified with a human gene that codes for a blood anticlotting factor. The anticlotting factor can then be extracted from the goat milk and used during surgery. To produce these genetically modified goats, scientists most likely (1) injected the anticlotting factor into the milkproducing glands of the animals (2) added modified DNA into the milk of the animals (3) inserted the human gene into the egg cells of goats (4) altered the nutritional requirements of newborn goats 76. Plants in species A cannot fight most fungal infections. Plants in species B make a protein that kills many fungi. One possible way for humans to produce species A plants with the ability to synthesize this protein would be to (1) mutate fungal DNA and introduce the mutated DNA into species B using a virus (2) add DNA from species B into the soil around species A (3) insert the gene for the protein from species B into a chromosome in species A (4) cross species A and a fungus to stimulate the synthesis of this protein page 27
77. The accompanying diagram illustrates some key steps of a procedure in one area of biotechnology. 78. The accompanying diagrams represent some steps in a procedure used in biotechnology. Letters X and Y represent the The letter X most likely represents (1) bacterial cells that are unable to synthesize insulin (2) human cells that are able to synthesize antibodies (3) bacterial cells that are able to synthesize insulin (1) hormones that stimulate the replication of bacterial DNA (2) biochemical catalysts involved in the insertion of genes into other organisms (3) hormones that trigger rapid mutation of genetic information (4) gases needed to produce the energy required for gene manipulation (4) human cells that are unable to resist antibiotics page 28
79. The diagram below represents a scientific technique in use today. 80. Which statement would most likely be used to describe the procedure represented in the diagram below? Scientists have used this technique to (1) produce hormones for human use at a lower cost than other methods (2) produce pathogens that are able to live in humans (3) clone human cells with desired characteristics (4) eliminate the need for laboratory production of medicines for humans (1) Enzymes are used to assemble an insulin gene, which is then attached to bacterial DNA. (2) Bacterial DNA is cut from a human DNA strand and inserted into a human cell to form an insulin gene. (3) The insulin gene is cut out of a human DNA strand using an enzyme and inserted into bacterial DNA, resulting in a combination of different DNA segments. (4) A gene is deleted from bacterial DNA to produce an insulin gene, which is then inserted into human DNA. page 29
81. Base your answer(s) to the following question(s) on the diagram below, which illustrates some steps in genetic engineering and on your knowledge of biology. 82. The accompanying diagram represents a technique used in biotechnology. State one way that enzymes are used in step 2. Name a specific substance that can be produced by this technique and state how humans have benefited from the production of this substance. page 30
83. Base your answer(s) to the following question(s) on the Universal Genetic Code Chart below and on your knowledge of biology. Some DNA, RNA, and amino acid information from the analysis of a gene present in five different species is shown in the chart on the next page. page 31
84. Using the information given, fill in the missing DNA bases in the DNA strand for species C in the chart on the next page. 85. Using the information given, fill in the missing mrna bases in the mrna strand for species B in the chart on the next page. 86. Using the Universal Genetic Code Chart, fill in the missing amino acids in the amino acid sequence for species A in the chart provided. 89. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. DNA samples were taken from three different species and used to determine the amino acid sequence for a portion of a particular protein. The amino acids were then compared in order to determine which species were most closely related. Some of the information is shown on the table below. Species A Species B Species C DNA base sequence mrna base sequence amino acid sequence DNA base sequence mrna base sequence amino acid sequence DNA base sequence mrna base sequence amino acid sequence GAC CUG LEU GAC LEU GAC CUG LEU TGA ACU THR AGA UCU TGC THR CTC GAG CTT GAA CAC GUG VAL CAC GUG VAL CAC VAL CTC GLU TGA ACU TGA ACU THR AGA UCU SER State one specific effect on the protein produced if an mrna code is changed from AGU to AGA. 87. Base your answer(s) to the following question(s) on the diagram below and on your knowledge of biology. 90. Base your answer(s) to the following question(s) on the diagram of a cell below. Identify the type of building block represented by the letters A, B, and C. 88. If the sequence of building blocks were changed, what effect could it most likely have on the protein? Choose either structure 3 or structure 4, write the number of the structure on the line below, and describe how it aids the process of protein synthesis. Structure: page 32
91. Base your answer(s) to the following question(s) on the information and diagram below and on your knowledge of biology. The diagram below shows the results of a test that was done using DNA samples from three bears of different species. Each DNA sample was cut into fragments using a specific enzyme and placed in the wells as indicated below. The DNA fragments were then separated using gel electrophoresis. 93. Base your answer(s) to the following question(s) on the table below, which represents the DNA codes for several amino acids. Amino Acid Cysteine Tryptophan Valine Proline Asparagine Methionine DNA Code Sequence ACA or ACG ACC CAA or CAC or CAG or CAT GGA or GGC or GGG or GGT TTA or TTG TAC 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. Which two bears are most closely related? Support your answer with data from the test results. 92. Identify one additional way to determine the evolutionary relationship of these bears. page 33
94. Base your answer(s) to the following question(s) 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 95. Base your answer(s) to the following question(s) on the table below, which represents the DNA codes for several amino acids. Amino Acid Cysteine Tryptophan Valine Proline Asparagine Methionine DNA Code Sequence ACA or ACG ACC CAA or CAC or CAG or CAT GGA or GGC or GGG or GGT TTA or TTG TAC The DNA sequence undergoes the following change: Identify one environmental factor that could cause a base sequence in DNA to be changed to a different base sequence. TACACACAAACGGGG TACACCCAAACGGGG How would the sequence of amino acids be changed as a result of this mutation? page 34