Mader Biology 14th Edition — Chapter 13 — Multiple Choice and True/False Review

Chapter 13 question 1. _____ occurs as _____ builds up in the system if Enzyme A is nonfunctional because of an inherited mutation. A) xeroderma pigmentosum; tyrosine B) androgen insensitivity; tyrosine C) albinism; melanin D) phenylketonuria; phenyalanine

D) phenylketonuria; phenyalanine.

Chapter 13 question 2. When a bacterium is introduced to a new environment with plenty of nutritional resources, binary fission will allow for rapid growth of the population (2-4-8-16-32-64 . . . etc.). However, there is usually a slight lag before the rapid growth begins. What is the best explanation for this lag period? A) The new media contains compounds that turn on repressor proteins. B) Structural genes act more slowly than metabolic genes. C) Binary fission becomes more and more efficient after each cell division. D) It takes time to induce and amplify the production of the enzymes needed for binary fission. E) It takes time for bacterial cells to duplicate enough organelles to digest new media.

D) It takes time to induce and amplify the production of the enzymes needed for binary fission.

Chapter 13 question 3. Which component in an operon is incorrectly matched with its function? A) regulator gene—binds to the repressor protein B) structural gene—makes mRNA by transcription C) operator—if not bound to the repressor, allows RNA polymerase to bind to the DNA D) promoter—where RNA polymerase first binds to DNA

A) regulator gene—binds to the repressor protein

Chapter 13 question 5. Which of the following structures is not part of an operon? A) promoter B) regulator gene C) operator D) All of these are part of an operon. E) structural gene

D) All of these are part of an operon.

Chapter 13 question 6. Which level of primary control in eukaryotic gene activity involves changes in the polypeptide chain before it becomes functional? A) feedback control B) posttranslational control C) transcriptional control D) posttranscriptional control E) translational control

B) posttranslational control

Chapter 13 question 7. The term "operon" comes from the Latin root word for A) controller. B) copy-producing. C) structure. D) works. E) gene.

D) works.

Chapter 13 question 8. Active genes in eukaryotic cells are associated with A) DNA with many methyl groups. B) heterochromatin. C) euchromatin. D) methylated RNA and histones.

C) euchromatin.

Chapter 13 question 10. If CAP is absent from a cell, what are the potential consequences? A) All of these areconsequences of the absence of CAP. B) The individual doesnot have a backup system for survival when glucose is absent. C) The individual will not be able to metabolize enough energy if glucose is absent. D) The individualcannot activate the catabolism of various other metabolites in the absence ofglucose.

A) All of these areconsequences of the absence of CAP.

Chapter 13 question 11. The level of genetic control that involves the processing of early RNA transcripts to mRNA and the rate at which mRNA leaves the nucleus is A) transcriptional control. B) translational control. C) posttranslational control. D) feedback control. E) posttranscriptional control.

E) posttranscriptional control.

Chapter 13 question 12. A deletion of one base pair that alters the sequence of codons is called a(n) A) oncogene. B) frameshift mutation. C) transposon. D) carcinogen. E) substitution mutation.

B) frameshift mutation.

Chapter 13 question 13. All genes are active at the same time in a prokaryotic cell and controlled by positive regulation, but not in a eukaryotic cell. True or False?

FALSE.

Chapter 13 question 15. The mRNA strand includes both introns and exons. True or False?

FALSE.

Chapter 13 question 16. In transcriptional control in eukaryotic cells A) Only two of thechoices are correct. B) enhancers may be involved in the promotion as well as regulation of gene transcription. C) a different combination of DNA-binding proteins (transcriptional factors) may regulate the activity of a particular gene. D) the control may be due to the phosphorylation of transcriptional factors by a kinase. E) All of the choices are correct.

E) All of the choices are correct.

Chapter 13 question 17. All of these are considered carcinogens EXCEPT A) ethylene dibromide (EDB). B) ziram, a chemical used to prevent fungal diseases on crops. C) cabbage and related vegetables. D) ultraviolet light. E) cigarette smoke.

C) cabbage and related vegetables.

Chapter 13 question 18. Which statement is NOT correct about the lac operon? A) Lactose binds to the repressor protein and inactivates it. B) The structural genes make products that allow lactose metabolism. C) It regulates the production of a series of five enzymes. D) It is an inducible system. E) It is normally turned off if glucose is present.

C) It regulates the production of a series of five enzymes.

Chapter 13 question 19. The regulator gene codes for the DNA-binding proteins that act as repressors. True or False?

TRUE.

Chapter 13 question 20. Once proteins are functional, they are no longer subject to cellular control. True or False?

FALSE.

Chapter 13 question 21. Identify the major tumor suppressor gene that is more frequently mutated in human cancers than any other known gene. A) p16 B) hemoglobin gene C) RB tumor-repressor gene D) p53 gene E) ras oncogene

D) p53 gene.

Chapter 13 question 22. A form of gene regulation that occurs while RNA is still in the nucleus is A) feedback control. B) rate of binding to ribosomes. C) enzymatic cleavage of a polypeptide. D) differential intron removal and exon splicing.

D) differential intron removal and exon splicing.

Chapter 13 question 23. The universal regulatory mechanism in eukaryotes for controlling gene expression includes A) control of the genes transcribed and the rate they are transcribed. B) control of polypeptides after they have been synthesized but before they are functional. C) control of the processing of mRNA after it is transcribed from DNA but before it leaves the nucleus, and control of the rate it leaves the nucleus. D) All of these mechanisms are used; there is no single universal mechanism. E) control of mRNA in the cytoplasm after it leaves the nucleus, including changes to mRNA before translation begins.

D) All of these mechanisms are used; there is no single universal mechanism.

Chapter 13 question 25. In the transcription of DNA, remodeling proteins push the histone portion of the nucleosome aside so that transcription may begin. True or False?

TRUE.

Chapter 13 question 26. One-third of all cancer deaths are due to mutations that arise from smoking tobacco. True or False?

TRUE.

Chapter 13 question 27. Germ-line mutations A) occur in sex cells. B) Only two of the answer choices are true. C) All of the answer choices are true about germ-line mutations. D) can be passed to subsequent generations. E) may range from having no effect to completely inactivating protein activity.

C) All of the answer choices are true about germ-line mutations.

Chapter 13 question 28. Which of the following problems can arise during posttranscriptional control? A) All of these areerrors that can occur during posttranscriptional control of geneexpression. B) Incomplete excising of all introns from the pre-mRNA strand, leaving fragments to be joined with the exons. C) Differentialsplicing of exons that can lead to an altered gene expression. D) Excising an exonfrom the pre-mRNA strand.

A) All of these areerrors that can occur during posttranscriptional control of geneexpression.

Chapter 13 question 29. "Jumping genes" that have the ability to move within and between chromosomes are called A) introns. B) oncogenes. C) exons. D) transposons. E) retroviruses.

D) transposons.

Chapter 13 question 32. A change in a regulatory gene A) can increase or decrease the expression of a structural gene. B) is always beneficial to the organism in which it occurs. C) must be dominant to be effective. D) is what happens in the production of sickle-cell hemoglobin.

A) can increase or decrease the expression of a structural gene.

Chapter 13 question 35. The genes of a single operon are all regulated by the same repressor, operator, and promoter. True or False?

TRUE.

Chapter 13 question 36. Which of the following series of events is associated with the formation of cancer? A) The proto-oncogenes mutate and become oncogenes which stop functioning altogether. There is also an associated increase in the tumor suppressor gene activity allowing uncontrolled growth of cells. B) The proto-oncogenes mutate and become oncogenes which are continuously active. There is also an associated loss of tumor suppressor gene activity allowing uncontrolled growth of cells. C) The oncogenes mutate and become proto-oncogenes which stop functioning altogether. There is also an associated increase in the tumor suppressor gene activity allowing uncontrolled growth of cells. D) The oncogenes mutate and become proto-oncogenes which are continuously active. There is also an associated loss of tumor suppressor gene activity allowing uncontrolled growth of cells.

B) The proto-oncogenes mutate and become oncogenes which are continuously active. There is also an associated loss of tumor suppressor gene activity allowing uncontrolled growth of cells.

Chapter 13 question 37. Mutagens and carcinogens are associated with A) None of the above. B) spontaneous mutations. C) transposon activity. D) induced mutations.

D) induced mutations.

Chapter 13 question 38. Which of the following situations would be considered an example of positive regulation of gene expression in a prokaryote? A) The CAP protein activating the lac operon when lactose is absent and glucose is present. B) The repressor protein activating the lac operon when glucose is absent and lactose is present. C) The CAP protein activating the lac operon when glucose is absent and lactose is present. D) The repressor protein activating the lac operon when lactose is absent and glucose is present.

C) The CAP protein activating the lac operon when glucose is absent and lactose is present.

Chapter 13 question 39. Which statement is NOT correct about the trp operon? A) Tryptophan acts as the corepressor. B) Tryptophan binds to the repressor protein and inactivates it. C) The structural genes make products that are part of an anabolic pathway for the synthesis of tryptophan. D) It is normally turned off if tryptophan is present.

B) Tryptophan binds to the repressor protein and inactivates it.

Chapter 13 question 40. The most critical level of eukaryotic genetic control is _____ control. A) transcriptional B) translational C) posttranslational D) feedback E) posttranscriptional

A) transcriptional

Chapter 13 question 41. The level of genetic control that involves the life span of the mRNA molecule and the ability of the mRNA to bind to ribosomes is _____ control. A) translational B) transcriptional C) posttranscriptional D) feedback E) posttranslational

A) translational

Chapter 13 question 42. Which of the following is a method of posttranscriptional control? A) Both C and D are methods of posttranscriptional control. B) the lifespan of an mRNA molecule C) how fast the mRNA leaves the nucleus D) transcription factors E) differential processing of mRNA

A) Both C and D are methods of posttranscriptional control.

Chapter 13 question 43. Androgen insensitivity is characterized by A) the internal sex organs of a female and may bear children. B) external female genitalia. C) a female karyotype. D) a lack of male hormones, such as testosterone.

B) external female genitalia.

Chapter 13 question 44. Frameshift mutations A) can result in a completely new codon sequence that results in the production of non- functional proteins. B) most often happen when one or more nucleotides are inserted or deleted from the DNA. C) applies to the reading frame (sequence of codons) being changed. D) All of the choices are correct.

D) All of the choices are correct.

Chapter 13 question 45. In the lac operon, if lactose is present, which of the following occurs? A) Lactose binds to the repressor, changing its shape so that it does not bind to the operator. RNA polymerase then transcribes the needed genes. B) Lactose binds to the repressor, changing its shape so that it can bind to the operator and the structural genes are not expressed. C) Lactose bind to RNA polymerase, which then binds to the promoter and transcribes the needed genes. D) Lactose binds to the operon, which attracts RNA polymerase, then transcription of the needed genes occurs.

A) Lactose binds to the repressor, changing its shape so that it does not bind to the operator. RNA polymerase then transcribes the needed genes.

Chapter 13 question 47. The DNA of a _____ is wrapped around histone molecules to form a "beaded string." A) prokaryote B) eukaryote C) bacterium D) All of the answer choices are correct.

B) eukaryote.

Chapter 13 question 49. You are more likely to develop some form of cancer if you A) All of the choices are correct. B) have a high incidence of cancer in your family history. C) are exposed to higher doses of radiation including X-rays. D) are exposed to carcinogens.

A) All of the choices are correct.