BIOLOGY EXAM
1) The formation of offspring carrying genetic information from a single parent is called 1) A) asexual reproduction. B) sexual reproduction. C) regeneration. D) spontaneous generation. E) All of these
A
102) The individual features of all organisms are the result of 102) A) genetics and the environment. B) genetics. C) genetics and cytoplasmic determinants. D) the environment and individual needs. E) the environment.
A
108) How many sex chromosome(s) is/are in a human gamete? A) 1 B) 2 C) 3 D) 4 E) 5
A
109) What is the normal complement of sex chromosomes in a human male? A) one X chromosome and one Y chromosome B) two X chromosomes C) two X chromosomes and one Y chromosome D) two Y chromosomes E) one Y chromosome
A
112) Any gene located on a sex chromosome A) is called a sex-linked gene. B) is called a dominant allele. C) is called a recessive gene. D) will exhibit pleiotropy. E) will exhibit codominance.
A
113) A color-blind woman marries a man who is not color-blind. All of their sons, but none of their 113) daughters, are color-blind. Which of the following statements correctly explains these results? A) The gene for color vision is linked to the X chromosome. B) The gene for color vision is completely dominant to the gene for sex determination. C) The gene for color vision is incompletely dominant to the gene for sex determination. D) The gene for color vision is linked to the Y chromosome. E) The gene for color vision is codominant with the gene for sex determination.
A
116) Female inheritance patterns cannot be analyzed by simply studying the X chromosome because 116) the X chromosome is A) obtained from both father and mother. B) physically too large to analyze accurately. C) too fragile for long-term analysis. D) too susceptible to mutations. E) too difficult to isolate from the other chromosomes.
A
121) Which of the following statements regarding a DNA double helix is always true? A) The amount of adenine is equal to the amount of thymine, and the amount equal to the amount of cytosine. B) The amount of adenine is equal to the amount of guanine, and the amount equal to the amount of cytosine. C) The amount of adenine is equal to the amount of thymine, and the amount equal to the amount of uracil. D) The amount of adenine is equal to the amount of cytosine, and the amount equal to the amount of thymine. E) The amount of adenine is equal to the amount of uracil, and the amount of to the amount of cytosine.
A
124) Which of the following could serve as a template for transcription in a eukaryotic cell? 124) A) ATTAGCGCT B) GAUCCGAUG C) GAAUCUCCG D) AUGCCGCGG E) Any of these
A
126) Which of the following statements regarding DNA is false? 126) A) DNA uses the nitrogenous base uracil. B) One DNA molecule can include four different nucleotides in its structure. C) DNA uses the sugar deoxyribose. D) DNA molecules have a sugar-phosphate backbone. E) DNA is a nucleic acid.
A
127) Which of the following statements regarding RNA is false? 127) A) RNA uses the sugar dextrose. B) RNA molecules have a sugar-phosphate backbone. C) RNA is a nucleic acid. D) One RNA molecule can include four different nucleotides in its structure. E) RNA uses the nitrogenous base uracil.
A
128) When one DNA molecule is copied to make two DNA molecules, the new DNA contains 128) A) 50% of the parent DNA. B) 75% of the parent DNA. C) 100% of the parent DNA D) 25% of the parent DNA. E) none of the parent DNA.
A
134) Experiments have demonstrated that the ʺwordsʺ of the genetic code (the units that specify amino 134) acids) are A) three-nucleotide sequences. B) single nucleotides. C) enzymes. D) two-nucleotide sequences. E) nucleotide sequences of various lengths.
A
145) Which of the following statements about eukaryotic RNA is true? 145) A) Exons are spliced together. B) Introns are added to the RNA. C) The modified RNA molecule is transported into the nucleus. D) A long tail of extra nucleotides is removed from the 5ʹ end of the RNA. E) A small cap of extra nucleotides is added to both ends of the RNA.
A
146) Which of the following takes place during translation? 146) A) the conversion of genetic information from the language of nucleic acids to the language of proteins B) the addition of nucleotides to a DNA template C) the conversion of genetic information from DNA nucleotides into RNA nucleotides D) DNA replication E) the conversion of genetic information from the language of proteins to the language of enzymes
A
150) ________ marks the end of a gene and causes transcription to stop. 150) A) A terminator B) Methionine C) RNA ligase D) Reverse transcriptase E) RNA polymerase
A
163) The lac operon of E. coli is ________ when the repressor is bound to lactose. 163) A) turned on B) turned off C) unregulated D) terminated E) elongated
A
165) The expression of the genes in the trp operon of E.coli is controlled by 165) A) a repressor that is active when it binds to tryptophan. B) an activator that turns the operon on by binding to DNA. C) a repressor that is inactive when it binds to lactose. D) an activator that permanently deletes genes in the tryptophan operon. E) a repressor that is active when it is alone.
A
166) Which of the following statements regarding DNA packing is false? 166) A) DNA packing tends to promote gene expression. B) A nucleosome consists of DNA wound around a protein core of eight histone molecules. C) Histones account for about half the mass of eukaryotic chromosomes. D) Prokaryotes do not have histones although they have proteins analogous to histones. E) Highly compacted chromatin is generally not expressed at all.
A
167) The ʺmosaicʺ fur color pattern as black and orange on a cat 167) A) results from X chromosome inactivation. B) usually occurs in males. C) occurs in male cats 25% of the time and in female cats 50% of the time. D) is the result of a homozygous recessive condition. E) is a result of alleles on the Y chromosome.
A
17) Which of the following options correctly describes the behavior of a tetrad during anaphase I of 17) meiosis? A) It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell. B) It splits into four chromosomes, which distribute in sister-chromosome pairs to the two poles of the dividing cell. C) It splits into two pairs of homologous, nonsister chromatids, and one pair goes to each pole of the dividing cell. D) It splits into four chromosomes, which distribute in random pairs to the two poles of the dividing cell. E) It goes intact to one pole of the dividing cell.
A
172) Silencers are sites on eukarytic DNA that 172) A) bind repressor proteins to inhibit the start of transcription. B) release mRNA. C) bind activators to inhibit the start of transcription. D) bind enhancers to promote the start of transcription. E) bind RNA promoters to promote the start of transcription.
A
187) The cloning of Dolly the sheep 187) A) demonstrated that the nuclei from differentiated mammalian cells can retain their full genetic potential. B) demonstrated that differentiated cells contain only a fraction of their full genetic potential. C) demonstrated, for the first time, that eggs are haploid and body cells are diploid. D) revealed that cloned mammals most resemble the sperm donor. E) revealed that cloned mammals most resemble the egg donor.
A
190) Which of the following possible uses of reproductive cloning is still considered by most to be an 190) unresolved ethical issue? A) the production of genetically identical humans for therapeutic purposes. B) the production of potentially valuable drugs C) the improvement of the quality of farm animals D) the production of organs in pigs for transplant into humans E) the production of genetically identical animals for experimentation
A
194) Mutations in the tumor-suppressor gene p53 can lead to cancer by 194) A) turning off a gene for a protein that inhibits cell division. B) relaying the signal in the absence of hormone binding to the receptor leading to uncontrolled cell growth. C) causing the production of excessive amounts of relay proteins. D) promoting the expression of mRNA that can interact with DNA, resulting in new mutations. E) increasing the production of growth hormones, which trigger faster cell growth.
A
196) The carcinogen known to cause the most cases of cancer is 196) A) tobacco. B) ultraviolet light. C) X-ray. D) salt. E) alcohol.
A
198) The production of multiple identical copies of gene-sized pieces of DNA defines 198) A) gene cloning. B) plasmid transformation. C) clonal selection. D) plasmolysis. E) tissue culturing.
A
200) DNA ligase binds 200) A) nucleotides together. B) exons together. C) an intron to an exon. D) polymerase to the promotor. E) introns together.
A
206) ʺSticky endsʺ are 206) A) DNA fragments with single-stranded ends. B) produced by the action of DNA ligase. C) always long sequences of a single nucleotide. D) produced by PCR. E) used by mRNA to attach to ribosomes.
A
21) Which of the following statements regarding mitosis and meiosis is false? 21) A) Meiosis provides for asexual reproduction. B) All the events unique to meiosis occur during meiosis I. C) In mitosis, the chromosomes replicate only once in the preceding interphase. D) Mitosis provides for growth and tissue repair. E) In meiosis, the chromosomes replicate only once in the preceding interphase.
A
211) What is the smallest number of cells needed to perform a successful DNA profile? A) 20 B) 1,200 C) 1,000 D) 200 E) 10
A
217) An advantage of using reverse transcriptase to prepare a gene for cloning is that 217) A) the resulting DNA strand will lack introns. B) reverse transcriptase is more efficient than DNA polymerase. C) the resulting DNA strand will lack exons. D) reverse transcriptase is more efficient than RNA polymerase. E) RNA is the genetic material of bacteria.
A
219) What is the preferred name of the technique used to determine if DNA comes from a particular 219) individual? A) DNA profiling B) DNA fingerprinting C) DNA scrutiny D) DNA synopsis E) DNA outline
A
221) The number of proteins in humans 221) A) is much greater than the number of genes. B) cannot be determined because the human genome is too complex. C) is less than half the number of genes. D) is approximately equal to the number of genes. E) has been determined by comparing the number of genes.
A
28) Which of the following is a feature of plant cell division that distinguishes it from animal cell 28) division? A) formation of a cell plate B) formation of a cleavage furrow C) disappearance and subsequent reappearance of the nucleolus D) lack of cytokinesis E) production of four (rather than two) new cells per mitotic division
A
3) Asexual reproduction requires ________ individual(s). A) 1 B) 0 C) 4 D) 3)2
A
34) Which of the following helps maintain the structure of chromosomes and control the activity of 34) genes? A) proteins B) the nuclear membrane C) centromeres D) ribosomes E) lipids
A
39) In the cell cycle, what happens duting M? A) Chromosomes separate and the cell divides B) DNA is synthesized C) Cytokinesis D) All of the above E) Nothing
A
43) During anaphase of a somatic cell 43) A) Chromosomes separate B) The cell actually divides into two C) DNA is replicated D) Chromosomes line up across the middle of the cell E) Chromosomes become visible
A
47) During meiosis, when would you expect to see tetrads 47) A) Prophase B) Metaphase C) Anaphase D) Telophase E) Never
A
48) During meiosis, when would you expect crossing over to happen? 48) A) Prophase B) Metaphase C) Telophase D) Never E) Anaphase
A
56) If ATTGCGTAT is a part of a cellʹs DNA, which of the following do you know would be part of a 56) sister chromatid made during S phase of mitosis in that cell? A) ATTGCGTAT B) TATGGGTTA C) TAAGCGATA D) TAACGCTAT E) Any of these
A
57) Daughter cells resulting from mitosis 57) A) are geneticaly identical B) have half as many chromosomes as the parent cell C) have twice as many chromosomes asteh parent cell D) have only one member of each homologous pair of chromosomes E) have twice as many sister chromatids as the parent cell
A
62) Research since Mendelʹs time has established that the law of the segregation of genes during 62) gamete formation A) applies to all sexually reproducing organisms. B) applies to all asexually reproducing organisms. C) applies to all forms of life. D) is invalid. E) applies only to unicellular organisms.
A
65) If A is dominant to a and B is dominant to b, what is the expected phenotypic ratio of the cross: 65) AaBb × AaBb? A) 9:3:3:1 B) 8:4:2:2 C) 16:0:0:0 D) 4:4:4:4 E) 1:1:1:1
A
7) Eukaryotic chromosomes differ from prokaryotic chromosomes in that they 7) A) are housed in a membrane-enclosed nucleus. B) are simpler. C) include fewer proteins. D) are copied immediately after cell division. E) are circular in structure.
A
76) Which of the following crosses will produce more genetic diversity in th e offspring than was 76) present in the parents? A) AaBb x AaBb B) aabb x Aabb C) AABB x aabb D) AAbb x AAbb E) B & C
A
8) Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures 8) called A) sister chromatids. B) chromatin. C) nucleoli. D) DNA transcripts. E) sister chromosomes.
A
89) The vast majority of people afflicted with recessive disorders are born to parents who were 89) A) not affected at all by the disease. B) slightly affected by the disease, showing some but not all of the symptoms. C) affected by the disease but had subclinical symptoms. D) subjected to some environmental factor that caused the disease in their children. E) both affected by the disease.
A
9) Which of the following occurs during interphase? 9) A) cell growth and duplication of the chromosomes B) a reduction in the size of the nuclear membrane C) duplication of the chromosomes D) cytokinesis E) separation of newly formed DNA to opposite ends of the cell
A
Approximately what percentage of human DNA is noncoding? A) 98.5% B) 37% C) 49% D)79% E) 99.9%
A
10) If the S phase were eliminated from the cell cycle, the daughter cells would 10) A) continue to function without the normal amount of DNA. B) have half the genetic material found in the parent cell. C) synthesize the missing genetic material on their own. D) be genetically identical to each other. E) be genetically identical to the parent cell.
B
100) In polygenic inheritance, 100) A) multiple alleles must be in the population. B) genes at several loci affect the same trait. C) traits must be sex-linked. D) genes affecting the trait must be linked. E) All of these
B
107) What would you expect to find at a single locus? A) Homologous pairs B) Genes that affect the same trait C) Sister chromatids D) All of these E) None of these
B
114) Sex-linked conditions are more common in men than in women because 114) A) men acquire two copies of the defective gene during fertilization. B) men need to inherit only one copy of the recessive allele for the condition to be fully expressed. C) the sex chromosomes are more active in men than in women. D) the genes associated with the sex-linked conditions are linked to the Y chromosome, which determines maleness. E) women simply do not develop the disease regardless of their genetic composition.
B
117) Which of the following people conducted the experiments that demonstrated that DNA is the 117) genetic material of bacteriophages? A) Griffith B) Hershey and Chase C) Beadle and Tatum D) Watson and Crick E) Franklin
B
12) During which phase of mitosis does the nuclear envelope reform and the nucleoli reappear? 12) A) metaphase B) telophase C) prophase D) interphase E) anaphase
B
120) The shape of a DNA molecule is most like A) a diamond ring. B) a twisted rope ladder. C) a gold necklace. D) a set of railroad tracks. E) the letter X.
B
123) If one strand of DNA is CGGTAC, the other complementary strand would be 123) A) GCCAUC. B) GCCATG. C) CGGTAC. D) GCCTAG. E) TAACGT.
B
13) Which of the following statements regarding the function of mitosis is false? 13) A) Mitosis allows organisms to repair tissues. B) Mitosis allows organisms to generate genetic diversity. C) Mitosis allows organisms to grow. D) Mitosis allows organisms to regenerate lost parts. E) Mitosis allows organisms to reproduce asexually.
B
137) Which of the following options best depicts the flow of information when a gene directs the 137) synthesis of a cellular component? A) protein → RNA → DNA B) DNA → RNA → protein C) DNA → tRNA → mRNA → protein D) DNA → amino acid → RNA → protein E) RNA → DNA → RNA → protein
B
138) The transfer of genetic information from DNA to RNA is called 138) A) promotion. B) transcription. C) elongation. D) translation. E) initiation.
B
156) Any change in the nucleotide sequence of DNA is called 156) A) an anticodon. B) a mutation. C) a translation. D) a codon. E) a transcription.
B
157) Which of the following statements about the problems created by cloning is false? 157) A) Cloning does not increase genetic diversity in the cloned species. B) Cloned animals live longer compared to naturally bred animals. C) Cloning endangered species may de-emphasize the need to preserve critical natural habitats. D) Cloned animals are less healthy than animals created by natural methods. E) Cloning leads to malfunctions in gene regulation.
B
16) During which stage of meiosis does synapsis and the formation of tetrads occur? 16) A) prophase II B) prophase I C) metaphase I D) interphase I E) interphase II
B
160) In a prokaryote, a group of genes with related functions, along with their associated control DNA 160) sequence, defines A) an allele. B) an operon. C) an exon. D) an intron. E) a chromosome.
B
164) ____________ is a sequence of nucleotides near the start of an operon of prokaryotic DNA, to 164) which an active repressor can bind. This results in blocking transcription. A) Promoter B) Operator C) Terminator D) Activator E) Enhancer
B
170) Which is the region that is the binding site for RNA polymerase? 170) A) Enhancer sequence B) Promoter sequence C) Operator sequence D) Repressor sequence E) All of these
B
171) Enhancers are 171) A) required to turn on gene expression when transcription factors are in short supply. B) the site on eukaryotic DNA to which activators bind. C) required to facilitate the binding of DNA polymerases. D) adjacent to the gene that they regulate. E) the products of transcription factors.
B
173) RNA splicing involves the 173) A) addition of a nucleotide poly A ʺtailʺ to the RNA molecule. B) removal of introns from the RNA molecule. C) addition of introns to the RNA molecule. D) removal of exons from the RNA molecule. E) addition of a nucleotide G ʺcapʺ to the RNA molecule.
B
177) Small pieces of RNA, about 20 nucleotides long, that can regulate gene expression by causing 177) either mRNA degradation or inhibition of translation, are called A) miniRNA B) microRNA C) nanoRNA D) monoRNA E) None of these
B
178) Which of the following mechanisms of controlling gene expression occurs in eukaryotes, but not in 178) prokaryotes? A) Control of transcription B) mRNA splicing C) Control of mRNA breakdown D) Control of translation initiation E) Protein activation
B
181) A signal outside a cell triggers changes in the transcription and translation inside the cell through 181) the process of A) protein activation. B) signal transduction pathways. C) X chromosome inactivation. D) protein breakdown. E) post-translational editing.
B
183) The fact that the nucleus from an adult somatic cell can be used to create all of the cell types in a 183) new organism demonstrates that the development depends on A) the control of cell division. B) the control of gene expression. C) the timing of meiosis. D) the timing of mitosis. E) C & D
B
191) Adult stem cells have limited therapeutic potential 191) A) because they lack a complete set of genes. B) because their developmental potential is limited to certain tissues. C) because they are fully differentiated. D) because scientists have no reliable method of identification. E) due to their excessive numbers in tissues.
B
192) A gene that can cause cancer when present in a single copy in a cell is called a(n) 192) A) proto-oncogene. B) oncogene. C) enhancer gene. D) silencer gene. E) carcinogen.
B
197) When DNA from two sources is combined into one single piece of DNA, it is known as 197) A) a vector. B) recombinant DNA. C) cloned DNA. D) a DNA library. E) a plasmid.
B
204) Restriction enzymes A) bind RNA fragments together. B) cut DNA at specific sites. C) stop transcription. D) edit proteins. E) bind together strands of DNA.
B
210) What is the standard tool used for DNA profiling by forensic scientists? A) RFLP B) STR analysis C) DNA microarrays D) PCR E) Gel electrophoresis
B
216) A cDNA library differs from a genomic library in that 216) A) genomic libraries are only stored in bacterial cells. B) cDNA libraries only contain information from active genes. C) cDNA libraries are more stable. D) the cDNA was constructed from introns only. E) the cDNA library contains more genes.
B
22) Both mitosis and meiosis are preceded by 22) A) prometaphase. B) interphase. C) anaphase. D) telophase. E) prophase.
B
222) Approximately what percentage of the human genome is identical to that of a chimpanzee? 222) A) 88.5% B) 98.8% C) 62.3% D) 50.0% E) 92.0%
B
25) If a species has 12 homologous pairs of chromosomes, how many chromosomes would be in each 25) sperm from a male of that species? A) 6 B) 12 C) 24 D) The answer depends on the number of sister chromatids produced during mitosis. E) You cannot determine the answer from the information given.
B
35) Sister chromatids are 35) A) unique to prokaryotes. B) tightly linked together at a centromere. C) formed when chromatids separate during cell division. D) made only of DNA. E) found right after a cell divides.
B
4) Two chromosomes in a nucleus that carry loci for the same traits in the same positions on the 24) chromosome but specify different versions of some traits constitute a pair of A) non-homologous chromosomes. B) homologous chromosomes. C) complementary chromosomes. D) parallel chromosomes. E) heterologous chromosomes.
B
4) Which of the following statements regarding prokaryotes is false? A) Most prokaryotes reproduce by binary fission. E) 2 3) 4) B) Prokaryotic chromosomes are more complex than those of eukaryotes. C) Prokaryotic cells are generally smaller and simpler than eukaryotic cells. D) Daughter prokaryotic chromosomes are separated by some sort of active movement away from each other and the growth of new plasma membrane between them. E) Prokaryotes are haploid.
B
40) In the cell cycle, what happens duting S? A) Chromosomes separate and the cell divides B) DNA is synthesized C) Chromosomes become visible D) Cytokinesis E) All of the above
B
45) During either mitosis or meiosis, when would you first expect to actually see chromosomes? 45) A) Interphase B) Prophase C) Metaphase D) Anaphase E) Telophase
B
49) Crossing over that contributes to genetic diversity occurs between 49) A) non-homologous chromosomes. B) non-sister chromatids. C) linked loci. D) multiple alleles. E) All of these
B
54) What happens during meiosis anaphase I that does not happen during mitosis anaphase? 54) A) Pairing of homologous chromosomes to form a tetrad B) Separation of members of homologous pairs of chromosomes C) cytokinesis D) DNA synthesis E) Sister chromatids separate
B
60) Varieties of plants in which self-fertilization produces offspring that are identical to the parents 60) are referred to as A) the F2 generation. B) true-breeding. C) independent crosses. D) hybrids. E) monohybrid crosses.
B
69) A test cross is 69) A) a mating between an individual of unknown genotype and an individual heterozygous for the trait of interest. B) a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest. C) a mating between an individual of unknown genotype and an individual homozygous dominant for the trait of interest. D) a mating between two individuals of unknown genotype. E) a mating between two individuals heterozygous for the trait of interest.
B
71) Dr. Smithʹs parents have normal hearing. However, Dr. Smith has an inherited form of deafness. 71) Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smithʹs parents could have which of the following genotypes? A) dd and dd B) Dd and Dd C) DD and DD D) DD and dd E) Dd and DD
B
73) Which of the crosses in the previous question would you expect to be ʺtrue breedingʺ? 73) A) B B) A & D C) B & C D) C E) All of them
B
79) If you tried to do a Punnett Square to calculate the phenotypic ratios resulting from the following 79) cross: RrYygg x RryyGg, how many squares would that Punnett Square have? A) 9 B) 16 C) 32 D) 64 E) The answer cannot be determined from the information given.
B
81) Which of the following are the predicted phenotypic ratios in offspring from a dihybrid cross? 81) A) 3:1 B) 9:3:3:1 C) 1:2:2:1 D) 1:2:1:2:4:2:1:2:1 E) The answer cannot be determined from the information given.
B
82) Alleles segregate during meiosis because 82) A) They are on different homologous chromosome pairs. B) They are on the same homologous chromosome pairs. C) They are at different loci. D) They are sex-linked. E) They are linked.
B
90) All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink 90) flowers. This means that the allele for red flowers is ________ to the allele for white flowers. A) dominant B) incompletely dominant C) codominant D) recessive E) pleiotropic
B
91) Imagine that beak color in a finch species is controlled by a single gene. You mate a finch 91) homozygous for orange (pigmented) beak with a finch homozygous for ivory (unpigmented) beak and get numerous offspring, all of which have a pale, ivory-orange beak. This pattern of color expression is most likely to be an example of A) crossing over. B) incomplete dominance. C) codominance. D) pleiotropy. E) polygenic inheritance.
B
93) Human blood types are a result of 93) A) multiple alleles at the same locus in the population. B) genes at different loci affect the same trait. C) sex linkage. D) linked loci. E) All of these
B
97) The sickle-cell trait in humans is considered pleiotropic because 97) A) it causes mutations. B) it affects several characteristics. C) it is sex-linked. D) it is represented by multiplealleles in the population. E) All of these
B
98) In human beings, which of the following genetic condition is associated with resistance to malaria? 98) A) Hemophilia B) Sickle cell trait C) Cystic fibrosis D) Huntingtonʹs disease E) Muscular dystrophy
B
103) Genes located close together on the same chromosomes are referred to as ________ genes and 103) generally ________. A) linked . . . sort independently during meiosis B) homologous . . . are inherited together C) linked . . . do not sort independently during meiosis D) codependent . . . do not sort independently during meiosis E) associated . . . sort independently during meiosis
C
104) Linked genes generally 104) A) reflect a pattern of codominance. B) show pleiotropy. C) do not follow the laws of independent assortment. D) show incomplete dominance. E) follow the laws of independent assortment.
C
115) In offspring from a cross involving a sex-link trait, a dominant phenotype female and a recessive 115) phenotype male, A) males will always have a recessive phenotype. B) females will always have a recessive phenotype. C) either sex could show a recessive phenotype depending on the female parent genotype. D) neither sex could show a recessive phenotype. E) The answer to this question cannot be determined.
C
133) Which of the following would be a product of a reaction carried out by a RNA polymerase? 133) A) Polypeptide B) A gene C) mRNA D) DNA E) ATTGCGACG
C
135) The directions for each amino acid in a polypeptide are indicated by a codon that consists of 135) ________ nucleotide(s) in an RNA molecule. A) 1 B) 2 C) 3 D) 4 E) 5
C
14) Which of the following statements regarding the function of mitosis is false? 14) A) Mitosis allows organisms to reproduce asexually. B) Mitosis allows organisms to repair tissues. C) Mitosis allows organisms to generate genetic diversity. D) Mitosis allows organisms to regenerate lost parts. E) Mitosis allows organisms to grow.
C
141) DNA ligase functions to 141) A) add nucleotides to the 5ʹend of an existing polynucleotide. B) add nucleotides to the 3ʹend of an existing polynucleotide. C) tie pieces of polynucleotide together. D) carry out translation. E) produce mRNA.
C
144) Which of the following occurs when RNA polymerase attaches to the promoter DNA? 144) A) elongation of the growing RNA molecule B) termination of the RNA molecule C) initiation of a new RNA molecule D) initiation of a new polypeptide chain E) addition of nucleotides to the DNA template
C
149) Which of the following statements about ribosomes is false? 149) A) Ribosomes coordinate the functioning of mRNA and tRNA. B) A ribosome consists of two subunits. C) The ribosomes of prokaryotes and eukaryotes are the same in structure and function. D) Each ribosome has binding sites for tRNA. E) Subunits of RNA are made of proteins and ribosomal RNA.
C
151) Where do transcription and translation occur in prokaryotic cells? 151) A) in the nucleus B) on the plasma membrane C) in the cytoplasm D) in the mitochondrion E) in the cell wall
C
152) Which of the following options most accurately lists the sequence of events in translation? 152) A) peptide bond formation → codon recognition → translocation → termination B) codon recognition → translocation → peptide bond formation → termination C) codon recognition → peptide bond formation → translocation → termination D) codon recognition → peptide bond formation → termination → translocation E) peptide bond formation → translocation → codon recognition → termination
C
153) Redundancy in the genetic code means that 153) A) some nucleotide triplets code for several amino acids B) each amino acid is coded for by a unique nucleotide triplet C) more than one nucleotide triplet can code for the same amino acid D) All of these E) None of these
C
161) The lac operon in E. coli 161) A) coordinates the production of tryptophan-utilizing enzymes when it is present. B) allows the bacterium to resist antibiotics in the penicillin family. C) prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment. D) uses activators to initiate the production of enzymes that break down lactose. E) regulates the rate of binary fission.
C
18) Which of the following statements regarding genetic diversity is false? 18) A) Genetic diversity is enhanced by independent orientation of chromosomes at metaphase I. B) Genetic diversity is enhanced by random fertilization. C) Genetic diversity is enhanced by mitosis of somatic cells. D) Genetic diversity is enhanced by meiosis of germ cells. E) Genetic diversity is enhanced by crossing over during prophase I of meiosis.
C
184) Most A) only a tiny fraction of their original set of genes, but can regenerate lost genes as needed. differentiated cells retain 184) B) a complete set of their genes, but lose the ability to express most of those genes. C) a complete set of their genes, and retain the ability to express those genes under certain circumstances. D) only a tiny fraction of their original set of genes. E) the ability to dedifferentiate, but then cannot return to their original differentiated state.
C
185) Why can some plants be cloned from a single cell? 185) A) Plant cells do not differentiate even when mature, so any cell can grow into an entire plant. B) Plant cells are able to retrieve genes lost to the environment during development. C) Plant cells can dedifferentiate and give rise to all of the specialized cells required to produce an entire plant. D) Plant cells are capable of self-renewal by utilizing cellular components from adjacent cells . E) Plant cells can produce genes to replace those lost during development.
C
188) Cloning to produce embryonic stem cells is called 188) A) transplantational cloning. B) reproductive cloning. C) therapeutic cloning. D) dedifferentiation. E) regenerative cloning.
C
189) Which of the following mammals has not yet been cloned and brought through the complete 189) gestation cycle? A) dog B) cat C) human D) pig E) cow
C
193) Mutations in the proto-oncogene ras and the tumor-suppressor gene p53 193) A) can enhance further mutations, which can develop into cancer. B) increase protein synthesis by the cell. C) disrupt normal regulation of the cell cycle, leading to uncontrolled cell growth. D) are rarely associated with cancers. E) can improve the chance of avoiding cancer as one ages.
C
199) In the process of human gene cloning using recombinant plasmids, the bacterial plasmid 199) A) is cultured inside the human cell, which contains the gene to be cloned. B) comes from the same organism as the gene of interest. C) functions as a vector. D) is used to insert the human gene into the bacterial chromosome. E) is the source of the gene to be cloned.
C
208) The polymerase chain reaction relies upon unusual, heat-resistant ________ that were isolated 208) from bacteria living in hot springs. A) phages B) restriction enzymes C) DNA polymerase enzymes D) plasmids E) mRNA
C
214) A collection of DNA fragments obtained from the genome of one organism, inserted by 214) recombinant DNA techniques into the genome of a host organism (one fragment per host genome), and maintained there is called a A) DNA collection. B) vector battery. C) genomic library. D) gene bank. E) DNA file.
C
218) A nucleic acid probe is 218) A) a promoter site that is associated with a specific set of genes. B) a virus that transfers DNA to a recipient cell. C) a piece of radioactively labeled DNA that is used to locate a specific gene. D) an enzyme that locates a specific restriction site on RNA. E) a plasmid that recognizes a specific DNA sequence.
C
26) If a species has 24 homologous pairs of chromosomes, how many chromosomes would be in each 26) unfertilized egg from a female of that species? A) 6 B) 12 C) 24 D) The answer depends on the number of sister chromatids produced during mitosis. E) You cannot determine the answer from the information given.
C
27) A pair of male human sex chromosomes is most like 27) A) identical twins. B) a knife, fork, and spoon. C) a bride and groom. D) a pair of blue jeans. E) the letters of the alphabet.
C
29) At the start of mitotic anaphase, 29) A) equivalent and complete collections of chromosomes have reached the two poles. B) sister chromatids separate. C) the centromeres of each chromosome come apart. D) daughter chromosomes begin to move toward opposite poles of the cell. E) the chromatid DNA replicates.
C
30) The phase of mitosis during which the nuclear envelope fragments and the nucleoli disappear is 30) called A) telophase. B) anaphase. C) prophase. D) metaphase. E) interphase.
C
33) Eukaryotic cells spend most of their cell cycle in which phase? 33) A) metaphase B) prophase C) interphase D) telophase E) anaphase
C
38) During which of the following cell cycle phases would thymine be used in the construction of a 38) nucleotide polymer? A) M B) G1 C) S D) G2 E) Any of these phases
C
41) During prophase 41) A) Chromosomes separate B) Chromosomes line up across the middle of the cell C) Chromosomes become visible D) The cell actually divides into two E) DNA is replicated
C
42) During metaphase of a somatic cell 42) A) DNA is replicated B) Chromosomes become visible C) Chromosomes line up across the middle of the cell D) Chromosomes separate E) The cell actually divides into two
C
63) The alleles of a gene are found at _______________________________ chromosomes. 63) A) the same locus on homologous mitochondrial B) the same locus on heterologous C) the same locus on homologous D) different loci on heterologous E) different loci on homologous
C
72) Which of the following crosses will produce more genetic diversity in the offspring than was 72) present in the parents? A) aa x aa B) aa x Aa C) Aa x Aa D) AA x AA E) None of these
C
74) How many different kinds (combination of alleles) of gametes would AaBbRr be able to make? 74) A) 2 B) 4 C) 8 D) 16
C
83) Genes for different traits would assort independently at meiosis because 83) A) They are on different homologous chromosome pairs. B) They are on the same homologous chromosome pairs. C) They are at different loci. D) They are sex-linked. E) They are linked
C
87) Which of the following statements best explains why dominant alleles that cause lethal disorders 87) are less common than recessive alleles that cause lethal disorders? A) Many lethal recessive alleles cause enhanced disease resistance when they are present in the heterozygous state, and carriers of these alleles have more children, on average, than other people. B) Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles. C) Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce. D) The presence of a lethal dominant allele causes sterility. E) Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause the death of the embryo.
C
88) Amniocentesis and chorionic villus sampling allow for ________ and ________ of the fetus so that 88) it can be tested for abnormalities. A) direct observation . . . biochemical testing B) sexing . . . imaging C) karyotyping . . . biochemical testing D) imaging . . . karyotyping E) imaging . . . biochemical testing
C
92) The expression of both alleles for a trait in a heterozygous individual illustrates 92) A) polygenic inheritance. B) pleiotropy. C) codominance. D) blending inheritance. E) incomplete dominance.
C
99) Which of the following terms refers to a situation where a single phenotypic character is 99) determined by the additive effects of two or more genes? A) Codominance B) Pleiotropy C) Polygenic inheritance D) Incomplete dominance E) Blending inheritance
C
HOw many sex chromosomes are in a human gamate? A) four B)two C)one D)three E)five
C
105) You conduct a dihybrid cross and then testcross the generation. A ________ ratio would make you 105) suspect that the genes are linked. A)3:1 B)1:2:1 C) 1:1:1:1 D) 7:7:1:1 E) 9:3:3:1
D
106) What would you expect to see for a ʺkaryotypeʺ? A) Sister chromatids B) Homologous pairs of chromosomes C) Any unusual chromosome structure if present D) All of these E) None of these
D
11) During which phase of mitosis do the chromosomes line up on a plane equi-distant from the two 11) spindle poles? A) anaphase B) interphase C) prophase D) metaphase E) telophase
D
110) The sex chromosome complement of a normal human male is A) YO. B) XX. C) XO. D) XY. E) YY.
D
118) When a T2 bacteriophage infects an Escherichia coli cell, which part of the phage enters the bacterial 118) cytoplasm? A) only the RNA B) the tail fibers C) the protein ʺheadpieceʺ and its enclosed nucleic acid D) only the DNA E) the whole phage
D
132) Which of the following events would occur during mRNA synthesis? 132) A) Adenine pairing with cytosine B) translation C) DNA ligase linking polynucleotide pieces D) Uracil pairing with adenine E) RNA polymerase linking thymine to adenine
D
140) Which of the following enzymes catalyzes the elongation of a new DNA strand? 140) A) helicase B) primase C) single-stranded binding protein D) DNA polymerase E) ligase
D
143) Which of the following enzymes catalyzes the linking together of RNA nucleotides to form RNA? 143) A) RNA ligase B) reverse transcriptase C) tRNA D) RNA polymerase E) a ribozyme
D
147) Which of the following is a function of tRNA? 147) A) joining to several types of amino acid B) helping to translate codons into nucleic acids C) recognizing the appropriate anticodons in mRNA D) joining to only one specific type of amino acid E) transferring nucleotides to rRNA
D
154) Which of the following statements regarding the flow of genetic information is false? 154) A) Ribosomes function as factories that coordinate the functioning of mRNA and tRNA. B) Eukaryotic mRNA is processed in several ways before export out of the nucleus. C) The codons in a gene specify the amino acid sequence of a polypeptide. D) Transcription occurs in the cytoplasm of eukaryotic cells. E) Polypeptides form proteins that determine the appearance and function of the cell and organism.
D
159) An operon consists of 159) A) a promoter only. B) a transcribed gene only. C) a regulatory gene only. D) a promoter, an operator, and transcribed genes E) a regulatory gene, a promoter, and transcribed genes
D
162) The fact that the nucleus from an adult somatic cell can be used to create all of the cell types in a 162) new organism demonstrates that development depends upon A) the timing of mitosis and meiosis. B) the position of cells within an embryo. C) the deposition of materials in the extracellular matrix. D) the control of gene expression. E) the timing of meiosis and cell migrations.
D
169) Proteins that bind to eukaryotic DNA and turn on gene expression by making it easier for RNA 169) polymerase to bind to a promoter are called A) regulators. B) inhibitors. C) operators. D) activators. E) repressors.
D
175) Which of the following permits a single gene to code for more than one polypeptide? 175) A) addition of different types of caps and tails to the final version of the mRNA strands B) protein degradation C) genetic differentiation D) alternative RNA splicing E) retention of different introns in the final version of the different mRNA strands
D
176) Which of the following mechanisms of controlling gene expression occurs outside of the nucleus? 176) A) Adding a cap and tail to mRNA B) mRNA splicing C) Control of transcription D) Control of translation E) DNA packing/unpacking
D
179) To initiate a signal transduction pathway, a signal binds to a receptor protein usually located in the 179) A) cytoplasm. B) cytosol. C) nucleus. D) plasma membrane. E) ER.
D
19) Independent orientation of chromosomes at metaphase I results in an increase in the number of 19) A) points of crossing over. B) homologous chromosomes. C) gametes. D) possible combinations of characteristics. E) sex chromosomes.
D
2) Which of the following statements regarding sexual and asexual reproduction is true? 2) A) Only offspring from asexual reproduction inherit traits from two parents. B) Cell division only occurs after sexual reproduction. C) Sexual reproduction typically includes the development of unfertilized eggs. D) Sexual reproduction is more likely to increase genetic variation than is asexual reproduction. E) Only asexual reproduction results from the union of a sperm and an egg.
D
203) ________ are a major source of restriction enzymes. 203) A) DNA technologies B) Parietal cells C) Chief cells D) Bacteria E) Archaea
D
212) Which of the following pieces of evidence would be considered the best for establishing biological 212) relatedness? A) pictures from family reunions B) testimony from relatives C) birth certificates D) a very close match in the DNA profile E) legal documents
D
215) Retroviruses such as HIV use ________ to convert information stored in their RNA to information 215) stored in DNA. A) a restriction enzyme B) DNApolymerase C) RNA polymerase D) reverse transcriptase E) DNA ligase
D
220) Which of the following statements regarding proteomics is correct? 220) A) Proteomics and genomics allow scientists to study life in an ever-increasing reductive approach. B) Proteomics involves the complete analysis of the prokaryotes. C) Proteomics is a straightforward task that is technically simple. D) Proteomics is the systematic study of the full set of proteins encoded by a genome. E) Proteomics is the study of protein interaction within a cell.
D
23) Which of the following statements is false? 23) A) A zygote is a fertilized egg. B) A typical body cell is called a somatic cell. C) Gametes are haploid cells. D) Gametes are made by mitosis. E) Somatic cells are diploid.
D
31) The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called 31) A) spindle formation. B) mitosis. C) binary fission. D) cytokinesis. E) telophase.
D
32) The genetic material is duplicated during 32) A) G2. B) G1. C) the mitotic phase. D) the S phase. E) mitosis.
D
37) What is/are considered asexual reproduction? 37) A) Binary fission B) Mitosis C) Meiosis D) A & B E) B & C
D
44) During cytokinesis of a somatic cell 44) A) Chromosomes separate B) Chromosomes line up across the middle of the cell C) Chromosomes become visible D) The cell actually divides into two E) None of these processes occurin somatic cells
D
48) Which of the following is not needed in order for translation to occur? 148) A) tRNA B) various enzymes and protein ʺfactorsʺ C) sources of energy, including ATP D) DNA template E) ribosomes
D
50) Which of the following would you expect to happen during meiosis but not mitosis? 50) A) Forming tetrad B) Crossing over C) Independent assortment D) All of these E) None of these
D
51) What happens to chromosomes during anaphase during mitosis? 51) A) Synapsis B) Crossing over C) All chromosomes convene on the imaginary plate in the equator of the cell D) Each chromosome separates its sister-chromatids toward the opposite poles of the cell E) Homologous chromosomes (each with two sister-chromatids still attached) separate towards the opposite poles of the cells
D
53) What happens to chromosomes during anaphase II of meiosis II? 53) A) Synapsis B) Crossing over C) All chromosomes convene on the imaginary plate in the equator of the cell D) Each chromosome separates its sister-chromatids toward the opposite poles of the cell E) Homologous chromosomes (each with two sister-chromatids still attached) separate towards the opposite poles of the cells
D
55) What happens during meiosis anaphase II that also happens during mitosis anaphase? 55) A) DNA synthesis B) Separation of members of homologous pairs of chromosomes C) Pairing of homologous chromosomes to form a tetrad D) Sister chromatids separate E) cytokinesis
D
58) Daughter cells resulting from meiosis 58) A) have only one member of each homologous pair of chromosomes B) have only one member of each pair of alleles C) have half as many chromosomes as the parent cell D) All of these E) None of these
D
59) Mendel conducted his most memorable experiments on 59) A) fruit flies. B) guinea pigs. C) roses. D) peas. E) mice.
D
6) Which of the following statements regarding cell division is false? 6) A) Cell division can reproduce an entire organism. B) Cell division is the basis of both sexual and asexual reproduction. C) Cell division is necessary for development to occur. D) Cell division is common in eukaryotes but rare in prokaryotes. E) Cell division ensures the continuity of life from generation to generation.
D
61) A monohybrid cross is 61) A) the first generation of a self-fertilized plant. B) the second generation of a self-fertilized plant. C) a breeding experiment in which the parental varieties have only one trait in common. D) a breeding experiment in which the parental varieties differ in only one character. E) a diploid plant that results from breeding two very different plants.
D
64) The phenotypic ratio resulting from a dihybrid cross showing independent assortment is expected 64) to be A) 9:1:1:3. B) 3:9:9:1. C) 3:1. D) 9:3:3:1.
D
68) Which of the following statements regarding genotypes and phenotypes is false? 68) A) An organism with two different alleles for a single trait is said to be heterozygous for that trait. B) The expressed physical traits of an organism are called its phenotype. C) Alleles are alternate forms of a gene. D) An allele that is fully expressed is referred to as recessive. E) The genetic makeup of an organism constitutes its genotype.
D
70) A carrier of a genetic disorder who does not show symptoms is most likely to be ________ to 70) transmit it to offspring. A) heterozygous for the trait and unable B) homozygous for the trait and able C) heterozygous for the trait and unlikely D) heterozygous for the trait and able E) homozygous for the trait and unable
D
75) Which of the following would be one of the gametes made by the individual in the previous 75) question ? A) aabbrr B) ABb C) AAb D) abr E) aRr
D
77) How many different kinds (combination of alleles) of gametes would an organism with the 77) genotype AaBbPpGg be able to make? A) 2 B) 4 C) 8 D) 16
D
80) According to your text, which of the following would be a dihybrid cross? 80) A) aabb x AABB B) aabb x aabb C) AABB x AABB D) AbBb x AaBb E) None of these
D
84) Which of the following processes is responsible for the genetic diversity seen in offspring? 84) A) Independent assortment B) Crossing over C) Mutation D) All of these E) None of these
D
86) Most genetic disorders of humans are caused by 86) A) drinking during pregnancy. B) dominant alleles. C) a mutation that occurs in the egg, sperm, or zygote. D) recessive alleles. E) multiple alleles.
D
94) Which of the following is an example of codominance in humans? 94) A) Cystic fibrosis B) Skin color C) Hemophilia D) ABO blood types E) Muscular Dystropy
D
95) A person with AB blood illustrates the principle of 95) A) pleiotropy. B) incomplete dominance. C) polygenic inheritance. D) codominance. E) blending inheritance.
D
96) Sickle-cell disease is an example of 96) A) multiple alleles and pleiotropy. B) codominance and blended inheritance. C) codominance and multiple alleles. D) codominance and pleiotropy. E) multiple alleles, pleiotropy, and blended inheritance.
D
the exception of identical twins, siblings who have the same two biological parents are likely 5) 5) With to look similar, but not identical, to each other because they have A) identical chromosomes, but different genes. B) the same combination of traits, but different genes. C) identical genes but different chromosomes. D) a similar but not identical combination of genes. E) only a 20% chance of sharing the same combination of genes.
D
101) Which of the following is essentially the opposite of pleiotropy? 101) A) Incomplete dominance B) Multiple alleles C) Codominance D) Blending inheritance E) Polygenic inheritance
E
119) The monomers of DNA and RNA are A) fatty acids. B) amino acids. C) nucleic acids. D) monosaccharides. E) nucleotides.
E
122) DNA replication A) results in the formation of four new DNA strands. 119) 120) 121) B) occurs through the addition of nucleotides to the end of the DNA molecule. C) produces two daughter DNA molecules that are complementary to each other. D) begins when two DNA molecules join together to exchange segments. E) uses each strand of a DNA molecule as a template for the creation of a new strand.
E
125) Which of the following could serve as a template for translation in a eukaryotic cell? 125) A) GAAUCUCCG B) AUGCCGCGG C) GAUCCGAUG D) AUUAGCGCU E) Any of these
E
129) Multiple origins of replication on the DNA molecules of eukaryotic cells serve to 129) A) remove errors in DNA replication. B) assure the correct orientation of the two strands in the newly growing double helix. C) reduce the number of ʺbubblesʺ that occur in the DNA molecule during replication. D) create multiple copies of the DNA molecule at the same time. E) shorten the time necessary for DNA replication.
E
130) In replication,why does a DNA strand grow only in the 5ʹ to 3ʹ direction? 130) A) because DNA polymerases can only add nucleotides to the 5ʹ end of the growing molecule B) because mRNA can only read a DNA molecule in the 5ʹ to 3ʹ direction C) because the DNA molecule only unwinds in the 5ʹ to 3ʹ direction D) because DNA polymerase requires the addition of a starter nucleotide at the 5ʹ end E) because DNA polymerases can only add nucleotides to the 3ʹ end of the growing molecule
E
131) Which of the following would obey the base-pairing rules of DNA synthesis ? 131) A) Adenine B) Thymine C) Guanine D) Cytosine E) All of these
E
136) The Central Dogma states that in a cell, information ʺflowsʺ from A) RNA to DNA to protein B) RNA to protein to DNA C) protein to RNA to protein D) protein to DNA to RNA E) DNA to RNA to protein
E
139) The ʺone gene-one polypeptideʺ theory states that 139) A) each polypeptide catalyzes a specific reaction. B) the synthesis of each gene is catalyzed by one specific enzyme. C) the function of each polypeptide is to regulate the synthesis of each corresponding gene. D) the synthesis of each enzyme is catalyzed by one specific gene. E) the function of an individual gene is to dictate the production of a specific polypeptide.
E
142) We would expect that a 15-nucleotide sequence will direct the production of a polypeptide that 142) consists of A) 5 amino acids. B) 3 amino acids. C) 6 amino acids. D) 2 amino acids. E) 4 amino acids.
E
15) Which of the following statements regarding mitosis and meiosis is false? 15) A) All sexual life cycles involve an alternation of diploid and haploid stages. B) A haploid cell has half the chromosomes of a diploid cell. C) A normal human zygote has 46 chromosomes. D) Meiosis only occurs in the sexual organs, producing gametes: sperms and eggs. E) Mitosis produces daughter cells with half the number of chromosomes as the parent cell.
E
155) A physical or chemical agent that changes the nucleotide sequence of DNA is called a(n) 155) A) polymerase. B) terminator. C) reverse transcriptase. D) anticodon. E) mutagen.
E
158) The term ʺgene expressionʺ refers to the 158) A) flow of information from parent to offspring. B) fact that each individual of a species has a unique set of genes. C) fact that individuals of the same species have different phenotypes. D) fact that certain genes are visible as dark stripes on a chromosome. E) process by which genetic information flows from genes to proteins.
E
168) Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off. 168) A) RNA splicing B) intron segments C) nucleosome packing D) DNA ligase E) regulatory proteins
E
174) The coding regions of a gene (the portions that are expressed as polypeptide sequences) are called 174) A) nucleosomes. B) introns. C) redundant coding sections. D) proto-oncogenes. E) exons.
E
180) Transcription factors attach to 180) A) proteins. B) plasma membrane receptors. C) signal molecules. D) mRNA. E) DNA.
E
182) The basis of cellular differentiation is 182) A) mutation. B) cellular specialization. C) cloning. D) the operon. E) selective gene expression.
E
186) Which of the following processes occurs when a salamander regenerates a lost limb? 186) A) The cell cycle is arrested and apoptosis begins. B) Oncogenes that cause accelerated cell division are turned on. C) A new salamander develops from the lost limb. D) The homeotic genes of the regenerating cells turn off. E) Certain cells in the limb dedifferentiate, divide, and then redifferentiate to form a new
E
195) Which of the following statements about proto-oncogenes is false? 195) A) Many proto-oncogenes code for growth factors. B) A mutation must occur in a cellʹs DNA for a proto-oncogene to become an oncogene. C) Proto-oncogenes are normal genes with the potential to become oncogenes. D) One of the earliest clues to understanding cancer was the discovery of a virus that causes cancer in chickens. E) A mutation in a tumor-suppressor gene can stop cell division immediately.
E
20) Which of the following statements regarding the differences between mitosis and meiosis is false? 20) A) Cells produced by mitosis are diploid, whereas cells produced by meiosis are haploid. B) In mitosis cytokinesis occurs once, whereas in meiosis cytokinesis occurs twice. C) In meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced. D) Mitosis, but not meiosis, occurs in somatic cells. E) Crossing over is a phenomenon that creates genetic diversity during mitosis.
E
201) DNA fragments that have matching sticky ends are joined by covalent bonds formed by the action 201) of A) DNA polymerase. B) DNA helicase. C) covalentase. D) a restriction enzyme. E) DNA ligase.
E
202) When plasmids are used to produce a desired protein, 202) A) the plasmids are inserted into the bacterial chromosome. B) the bacterial genome and plasmid are inserted into the genome of the cell containing the desired gene (perhaps the cell of a plant or animal). C) the bacterial chromosome is genetically engineered and the plasmid is used to help the bacterium replicate. D) the plasmids multiply and produce the protein outside of the bacterium. E) the desired gene is inserted into the plasmid and the plasmid is returned to the bacterium by transformation.
E
205) Restriction enzymes specifically recognize and cut short sequences of DNA called 205) A) DNA fragments. B) promoter sequences. C) sticky ends. D) short terminal repeats. E) restriction sites.
E
208) The polymerase chain reaction relies upon unusual, heat-resistant ________ that were isolated 208) from bacteria living in hot springs. A) phages B) restriction enzymes C) DNA polymerase enzymes D) plasmids E) mRNA
E
209) Gel electrophoresis sorts DNA molecules on the basis of their A) ability to bind to mRNA. B) solubility in the gel. C) solubility in water. D) nucleotide sequence. E) size.
E
36) Which of the following types of organisms commonly demonstrates polyploidy? 36) A) amphibians B) reptiles C) mammals D) fish E) flowering plants
E
46) During mitosis, when would you expect to see tetrads 46) A) Prophase B) Metaphase C) Anaphase D) Telophase E) Never
E
52) What happens to chromosomes during anaphase I of meiosis I? 52) A) Synapsis B) Crossing over C) All chromosomes convene on the imaginary plate in the equator of the cell D) Each chromosome separates its sister-chromatids toward the opposite poles of the cell E) Homologous chromosomes (each with two sister-chromatids still attached) separate towards the opposite poles of the cells
E
66) Mendelʹs law of independent assortment states that A) genes sort independently of each other in animals but not in plants. B) chromosomes sort independently of each other during mitosis and meiosis. C) independent sorting of genes produces polyploid plants under some circumstances. D) genes are sorted concurrently during gamete formation. E) each pair of alleles segregates independently of the other pairs of alleles during gamete formation.
E
67) All the offspring of a cross between a black-eyed organism and an orange-eyed organism have 67) black eyes. This means that the allele for black eyes is ________ the allele for orange eyes. A) recessive to B) better than C) more aggressive than D) codominant to E) dominant to
E
78) Which of the following would you expect to be a gamete made by the individual in the previous 78) question? A) AbPg B) ABPG C) abpg D) ABpg E) Any of these
E
85) If there are multiple alleles in a population, indicated by a1, a2, a3, a4, ..., an, then one individual 85) can have A) a1a2 B) a4a9 C) a3a7 D) a1a3 E) Any of these
E
