Name: Date: 1. A strand of DNA consists of thousands of smaller, repeating units known as A. lipids B. amino acids C. nucleotides D. polysaccarides 2. Which two bases are present in equal amounts in a double-stranded DNA molecule? A. cytosine and thymine B. adenine and thymine C. adenine and uracil D. cytosine and uracil 3. The DNA code for a particular amino acid contains a sequence of how many nucleotides? A. 5 B. 6 C. 3 D. 4 4. The genetic material in living organisms is composed of organic molecules known as A. starches B. lipids C. nucleic acids D. fatty acids 5. Two genes are linked if they are A. located on separate sex chromosomes B. members of an allelic pair C. located on the same chromosome D. able to segregate at random 6. In a DNA molecule, the number of guanine nucleotides will most likely equal the number of A. adenine nucleotides B. thymine nucleotides C. cytosine nucleotides D. ribose nucleotides 7. Pairs of genes that control the same trait are known as A. alleles B. gametes C. hybrids D. loci 8. Allelic pairs of genes are located only A. on homologous pairs of chromosomes B. in a DNA nucleotide C. in organisms that are homozygous D. on nonhomologous chromosomes page 1
9. Which two scientists proposed the double helix arrangement of this molecule A. Hardy and Weinberg B. Darwin and Lamarck C. Watson and Crick D. Mendel and De Vries 10. In humans there are 23 pairs of chromosomes. One pair of the 23 are sex chromosomes. The other 22 pairs are known as A. autosomes B. homozygotes C. heterozygotes D. centrosomes 11. Select the nucleic acid molecules, chosen from the list below, that is best described by the statement shown. May contain the four bases adenine, cytosine, guanine, and thymine A. DNA molecules, only B. RNA molecules, only C. Both DNA and RNA molecules D. Neither DNA nor RNA molecules page 2
12. CHROMOSOME THAT CARRIES THE DOMINANT ALLELE FOR HEIGHT CHROMOSOME THAT CARRIES THE RECESSIVE ALLELE FOR HEIGHT CHROMOSOME THAT CARRIES THE DOMINANT ALLELE FOR SEED SHAPE CHROMOSOME THAT CARRIES THE RECESSIVE ALLELE FOR SEED SHAPE Which statement correctly describes the location of the alleles for height and seed shape? A. The dominant alleles for height and seed shape are located on the same chromosome. B. The dominant and recessive alleles are located on the same member of a homologous pair of chromosomes. C. The alleles for height are located on a different homologous pair of chromosomes than the alleles for seed shape. D. The dominant alleles are located on one pair of homologous chromosomes and the recessive alleles are located on another pair of homologous chromosomes. 13. Which diagram represents those chromosomes that are responsible for the heterozygous genotype for height? A. B. C. D. 14. Asexual reproduction of diploid organisms normally results in new organisms that contain cells with A. more chromosomes than are found in the cells of the parent B. the n number of chromosomes C. the 2n number of chromosomes D. fewer chromosomes than are found in the cells of the parent 15. Which process is illustrated in the diagram? A. segregation B. replication C. crossing-over D. nondisjunction 16. The individual strands of a double-stranded chromosome are joined together by a A. cilium B. cyton C. chromatid D. centromere page 3
17. Traits that are controlled by genes found on an X-chromosome are said to be A. autosomal dominant B. autosomal recessive C. codominant D. sex-linked 18. The diagram shown represents a pair of homologous autosomes. The letters B and b represents genes for a certain trait. These letters also represent A. an allelic pair of genes B. linked genes C. genes for sex determination D. homozygous genes 19. Which statement best describes chromosomes that contain genes for the same characteristics? A. They are present in a normal gamete. B. They are homologous. C. They occur in the same monoploid cell. D. They are linked. 20. A mutation may occur in a gene as a result of the A. synthesis of a spindle apparatus B. loss of a nucleotide C. loss of a nucleolus D. replication of centromeres 21. Base your answer(s) to the following question(s) on the information and diagram below and on your knowledge of biology. In cats, gene E produces yellow fur and gene B produces black fur. A cat that inherits both of these genes has patches of yellow and black fur and is known as a calico. The alleles for black or yellow are located on the X-chromosome. The cross X B Y X B X E is illustrated in the square below. Yellow male offspring are represented by A. 1 B. 2 C. 3 D. 4 22. In humans, the gene for polydactyly (having extra fingers or toes) is dominant over the gene for the normal number of digits. If parents who are both homozygous dominant for polydactyly have four children, how many of these children would most likely have extra fingers or toes? A. 0 B. 2 C. 3 D. 4 page 4
23. Base your answer(s) to the following question(s) 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 24. The genotype of individual 2 could be A. EE, only B. Ee, only C. ee D. EE or Ee 25. The diagram shown represents a cell that will undergo mitosis. Which diagrams below best illustrate the nuclei of the daughter cells that result from a normal mitotic cell division of the parent cell shown? A. + B. + C. + D. + 26. Normally, a complete set of chromosomes (2n) is passed on to each daughter cell as a result of A. reduction division B. mitotic cell division C. meiotic cell division D. nondisjunction 27. Uncontrolled cell division is characteristic of A. cancer B. meiosis C. budding D. sporulation 28. The diploid chromosome number in a certain species of fish is 20. How many chromosomes would normally be found in bone cell of this fish? A. 10 B. 20 C. 23 D. 40 page 5
29. The diagram shown represents a microscopic structure observed during the process of cell division. Letter B indicates a A. centrosome B. spindle fiber C. chromatid D. cell plate 30. Which diagram most correctly represents the process of mitosis? A. B. C. D. 31. Which statement best describes a difference between cell division in plant and animal cells? A. In animal cells, cytoplasmic division is accomplished by pinching in of the cell membrane, while in plant cells a cell plate is synthesized. B. In plant cells, cytoplasmic division is accomplished by a pinching in of the cell membrane, while in animal cells a cell plate is synthesized. C. In plant cells, centrosomes have a distinct role in spindle formation, while in animal cells centrosomes do not function during cell division. D. In animal cells, replication of chromosomes occurs during the nondividing phase, while in plant cells replication occurs when the nuclear membrane disintegrates. 32. Which is the correct sequence for the stages of mitotic cell division represented by the diagrams shown? A. A B C D B. A C D B C. B A D C D. B C D A A B C D 33. Which is a true statement about normal mitotic cell division? A. Each daughter cell produced has only one-fourth the number of chromosomes of the parent cell. B. Each daughter cell produced has only one-half the number of chromosomes of the parent cell. C. Each daughter cell produced has the same number of chromosomes as the parent cell. D. Each daughter cell produced has twice the number of chromosomes of the parent cell. page 6
34. What would most likely result if mitosis was not accompanied by cytoplasmic division? A. two cells, each with one nucleus B. two cells, each without a nucleus C. one cell with two identical nuclei D. one cell without a nucleus 35. The cell in the diagram below illustrates a stage of mitotic cell division. Letter B indicates the A. paired chromosomes B. centrioles C. cell plate D. endoplasmic reticulum 36. Meiotic cell division in animals is directly responsible for the A. formation of gametes B. fertilization of an egg C. growth of a cell D. production of muscle cells 37. In a certain species of meadowmouse, dark coat color is dominant over cream coat color. If heterozygous dark-coated male mice are mated with cream-coated female mice, what would be the expected percentage of phenotypes in their offspring? A. 25% dark coated, 75% cream coated B. 50% dark coated, 50% cream coated C. 75% dark coated, 25% cream coated D. 100% dark coated 38. There are multiple alleles for the ABO blood group. Why are there only two of these alleles normally present in any one individual? A. There are not enough nucleotides in a red blood cell to produce a third allele. B. Each parent contributes only one allele for the ABO blood group to the offspring. C. Each allele in the ABO group must be either dominant or recessive. D. Blood group alleles are not segregated during meiosis. page 7
39. Which process is represented by the diagram shown? A. germination B. fertilization C. mitotic cell division D. meiotic cell division 40. A cross between two tall garden pea plants produced 314 tall plants and 98 short plants. The genotypes of the tall parent plants were most likely A. TT and tt B. TT and Tt C. Tt and Tt D. TT and TT 41. A man who has blood type AB marries a woman who has blood type B. This couple would not normally have a child with which genotype? A. I A i B. I B I B C. I A B B D. ii 42. What percent of the male offspring produced by a father with normal vision and a colorblind mother are expected to be colorblind? A. 0% B. 33% C. 75% D. 100% 43. Which usually occurs in the first meiotic division of a primary sex cell? A. fertilization B. polyploidy C. crossing-over D. differentiation 44. During egg cell production in a human female, the 21st pair of chromosomes may fail to separate. This failure to separate is known as A. crossing-over B. gene mutation C. polyplody D. nondisjunction 45. The letters in the following crosses represent parental blood types. Which cross could produce offspring that represent all four blood types of the ABO blood group? A. I A I A I A I B B. ii I A i C. I A I B I A I B D. I A i I B i page 8
46. The best way to determine the coat-color phenotype of a guinea pig is to A. X-ray the animal B. prepare a chromosome slide C. analyze a blood sample D. observe the organism 47. Some studies of identical human twins show that their IQ, height, and talents, may be different. The best explanation for these differences is that A. the environment interacts with genes in the development and expression of inherited traits. B. heredity and environment have no influence on the expression of phenotypes C. the genotype of twins depends on the interaction of diet and hormone control D. people are considered identical if at least half their genes are the same 48. In guinea pigs, black coat color (B) is dominant over white coat color (b). When two black guinea pigs were mated, the ratio of black-coated offspring to white-coated offspring was 3 : 1. In this cross, the parental genotypes were most likely A. Bb Bb B. BB bb C. Bb bb D. BB Bb 49. A person with type O blood marries a person with type AB blood. Possible blood genotypes of their children are A. I A i and I B I B B. I B I B and I A I A C. I A i and I B i D. I A I B and ii 50. Which represents the genotype of a homozygous condition? A. Bb B. BC C. bb D. bc 51. What percentages can be expected in the offspring of a cross between a female carrier for color blindness and a male with normal color vision? A. 25% normal males, 25% colorblind males, 25% normal females, 25% carrier females B. 25% normal males, 25% colorblind males, 25% carrier females, 25% colorblind females C. 75% normal males, 25% carrier females D. 50% colorblind males, 50% colorblind females 52. A change in gene linkage during meiotic cell division would most likely result from A. DNA replication B. ATP synthesis C. crossing-over D. independent assortment page 9
53. Which sequence represents the process of meiosis? A. n n B. 2n n C. n 2n D. 2n 2n 54. In the diagram shown, in which structure would homologous pairs of chromosomes normally be present? A. 1, only B. 2, only C. 3, only D. either 1 or 2 1 + 2 3 55. Corn seeds of the same species were separated into two groups. One group was grown in the dark and the other group was grown in the light. All other environmental conditions remained constant. After a week, the seeds germinated in the dark produced no green-leaved plants and 97 white-leaved plants, while seeds germinated in the light produced 74 green-leaved plants and 23 white-leaved plants. The plants originally grown in the dark were then placed in the light. After 2 days, 73 white-leaved plants turned green and 24 stayed white. From these observations, it may be concluded that A. neither heredity nor environment is important in determining the phenotype of corn plants B. both heredity and environment are important in determining the phenotype of corn plants C. environment is the only factor that determines the phenotype of corn plants D. heredity is the only factor that determines the phenotype of corn plants 56. The transfer of a section of one chromosome to a nonhomologous chromosome is known as A. synapsis B. deletion C. translocation D. disjunction 57. Which is a true statement about people with the genotype I A I B for blood type? A. They have two alleles that are codominant. B. They exhibit a type O phenotype. C. They are homozygous for blood type A. D. They can have only type O children. 58. Genes for two different traits that are located next to each other on the same chromosome would most likely be A. inherited separately B. codominant C. recombined D. inherited together 59. A human male will normally transmit the genes on his X-chromosome to A. his sons, only B. his daughters, only C. all of his sons and daughters D. half of his sons and half of his daughters page 10
60. The alleles for red hair and freckles are usually inherited together. Which statement best explains this pattern of inheritance? A. Genes for these traits are linked. B. Red hair and freckles are sex-linked traits. C. Crossing-over has occurred. D. Dominant alleles are always inherited together. 61. A person has type A blood. Which possible genotype could this person have? A. I A i or I B i B. I A I A or I A i C. I A I A or ii D. I A I B or I A I A 62. Synapsis, crossing-over, and disjunction are events that take place during the process of A. mitosis B. meiosis C. internal fertilization D. binary fission 63. A diploid cell of a normal human male contains A. 22 autosomes and two Y-chromosomes B. 22 pairs of autosomes and two Y-chromosomes C. 22 pairs of autosomes, one X-chromosome, and one Y-chromosome D. 22 autosomes and two X-chromosomes 64. Which diagram represents a sperm that can unite with a normal egg to produce a zygote that will develop into a normal human male embryo? A. B. C. D. page 11
65. Base your answer(s) to the following question(s) on the pedigree chart below and on your knowledge of biology. The pedigree chart represents the inheritance of color blindness through three generations. Barbara is expecting another child. What is the probability that the new baby will be colorblind? A. 0% B. 25% C. 50% D. 100% 66. Which statement about the genotype of Linda and Donna regarding color blindness is correct? A. Both carry one recessive allele. B. Linda is a carrier, and Donna is homozygous dominant. C. Both are homozygous recessive. D. Linda is homozygous dominant, and Donna is a carrier. 67. Certain genetic disorders can be detected by preparing and studying an enlarged photograph of paired chromosomes from a cell. The preparation of this photograph is known as A. genetic screening B. karyotyping C. genetic counseling D. amniocentesis page 12
68. A karyotype is shown in the diagram. Information in this karyotype indicates that the individual is a A. female with sickle-cell anemia B. male with Tay-Sachs disease C. female with Down syndrome D. male with phenylketonuria 69. Structure B in the diagram represents A. a zygote B. an ovule C. a gonad D. an egg nucleus 70. In animals that reproduce sexually, which is the correct sequence for the development of a new organism? A. gametes zygote fertilization embryo B. fertilization zygote gametes embryo C. zygote gametes fertilization embryo D. gametes fertilization zygote embryo page 13
71. Which DNA strand represents the complementary base sequence to the portion of a DNA strand represented in the diagram shown? A. B. C. D. 72. What is the relationship between an organism s DNA and protein specificity? A. DNA becomes a specific part of the protein structure. B. DNA determines the ribosomal RNA sequence that becomes part of the protein structure. C. DNA determines which RNA molecules are incorporated into protein molecules. D. DNA determines the amino acid sequence of each protein. 73. A DNA molecule with the base sequence A-G-C-T-C-A was used as a template for the synthesis of a messenger RNA molecule. Which base sequence correctly represents the corresponding portion of this RNA molecule? A. T-C-A-G-C-A B. U-C-G-A-G-U C. A-G-C-U-C-A D. A-T-G-A-C-T 74. The sequence of bases in one strand of a DNA molecule is arranged in the order adenine guanine thymine cytosine. The sequence of bases in the complementary strand is A. adenine cytosine thymine guanine B. guanine adenine cytosine uracil C. thymine cytosine adenine guanine D. cytosine thymine guanine adenine 75. The sequence of nitrogen bases on the complementary chain in the diagram is A. T-A-G-C B. U-G-A-C C. T-G-A-C D. U-A-G-C page 14
76. The molecule represented by the lettered symbols shown is a A. nucleotide B. codon C. triplet code D. base pair 77. As part of its structure, a known gene contains the base sequence A-A-T-C-G-A. An alteration of this sequence to A-A-C-C-G-A is known as a A. deletion B. disjunction C. mutation D. segregation 78. A normal bacterial cell carries on the chemical reaction represented. A certain mutant bacterial cell cannot produce substance B. The mutation was most likely the result of a change in the A enzyme X B A. ribosome on which enzyme X is made B. ability of the DNA to replicate C. amino acid sequence of RNA D. gene that codes for enzyme X 79. A change in the sequence of bases in a DNA molecule is known as A. bacterial transformation B. a chromosomal replication C. a gene mutation D. protein synthesis 80. Select the nucleic acid molecules, chosen from the list below, that is best described by the statement shown. Contains thymine A. DNA, only B. Messenger RNA, only C. Transfer RNA, only D. DNA, messenger RNA, and transfer RNA 81. Select the nucleic acid molecules, chosen from the list below, that is best described by the statement shown. Carries instructions from the nucleus to the cytoplasm A. DNA, only B. Messenger RNA, only C. Transfer RNA, only D. DNA, messenger RNA, and transfer RNA 82. Select the term, chosen from the list below, that is best described by the statement shown. A particular sequence of neucleotide triplets that determines the order of amino acids assembled during protein synthesis A. Genetic Code B. Gene pool C. Gene frequency D. Genotype page 15
83. During protein synthesis, amino acids in the cytoplasm are picked up by molecules of A. transfer RNA B. messenger RNA C. mitochondrial DNA D. nuclear DNA 84. The sequence of amino acids that make up a protein molecule is determined by the sequence of A. nitrogenous bases in DNA B. sugars in RNA C. cytoplasmic genes in the nucleus D. ribosomes on the endoplasmic reticulum 85. The process represented in the diagram is A. lipid digestion B. cell respiration C. protein synthesis D. protein hydrolysis page 16
86. Select the nucleic acid component, chosen from the diagrams shown, that is best described by the statement: Carries a code from the nucleus to the site of protein synthesis. A. B. C. D. page 17
87. Select the nucleic acid component, chosen from the diagrams shown, that is best described by the statement: Represents a single nucleotide A. B. C. D. 88. The difference in amino acids indicated in the circle portion of the diagram shown causes a change in the shape of red blood cells. What is the probable cause of this difference in the hemoglobin molecules? A. the inability to synthesize a specific enzyme, causing an accumulation of fat B. the substitution of one kind of nucleotide for another in a DNA molecule C. an abnormal metabolism of phenylalanine D. a recessive allele located on an X-chromosome Amino Acids Glu = glutamic acid His = histadine Leu = leucine Lys = lysine Pro = proline Thr = threonine Val = valine page 18
89. Messenger RNA (mrna) Codes for Selected Amino Acids Amino Acid Leucine Arginine Phenylalanine Valine Lysine mrna Code C C A C G A U U U G U U A A A 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 90. Some events that take place during the synthesis of a specific protein are listed. A) Messenger RNA attaches to a ribosome. B) DNA serves as a template for RNA production. C) Transfer RNA bonds to a specific codon. D) Amino acids are bonded together. E) RNA moves from the nucleus to the cytoplasm. The correct order of these events is A. B E A C D B. D A E C B C. B C E D A D. C B A E D page 19