McGraw-Hill Online Learning Center Test<BLURT>

McGraw-Hill Online Learning Center Test


1. Viruses contain ________. (p. 506) A. an inner nucleic acid core
B. an outer protein coat
C. both 1 and 2
D. all of the complexity of eukaryotic cells


2. The number of purines in DNA is always double the number of pyrimidines. (p. 507) A. True
B. False


3. DNA is a polymer of _________. (p. 507) A. sugars
B. fats
C. amino acids
D. adenosine triphosphates
E. nucleotides


4. A nucleotide is built from how many subunits? (p. 508) A. one
B. two
C. three
D. four
E. five


5. A polynucleotide strand has a backbone made of alternating phosphate and sugar molecules. (p. 508) A. True
B. False


6. The strands in DNA twist about one another forming a __________. (p. 508) A. straight spiral
B. circular strand of chromatin
C. broken ladder
D. left-ascending staircase
E. double helix


7. The complementary bases in DNA are _________. (p. 508) A. adenine with thymine
B. guanine with cytosine
C. both 1 and 2
D. cytosine with thymine
E. adenine with guanine


8. DNA is genetic material that _________. (pp. 507-510) A. replicates
B. undergoes mutations
C. stores information
D. does all of the above


9. DNA has four types of nucleotides because there are ______ different bases. (p. 508) A. two
B. three (plus the lack of)
C. four
D. eight
E. 23


10. DNA can differ between species because the base pairs can be in any order. (p. 508) A. True
B. False


11. In DNA, each strand can serve as _________ for the formation of a complementary strand. (p. 509) A. a perfect model
B. a template
C. an enzyme
D. energy


12. The bonds between the DNA base pairs are strong covalent bonds. (p. 509) A. True
B. False


13. The enzyme called DNA ______ joins the complementary nucleotides. (p. 509) A. ligase
B. lipase
C. synthetase
D. polymerase
E. conjugase


14. RNA contains the sugar ______. (p. 510) A. sucrose
B. ribose
C. fructose
D. phosphate-sugar
E. deoxyribose


15. ______ occurs in RNA in place of thymine. (p. 509) A. Adenine
B. Guanine
C. Cytosine
D. Uracil
E. Ribose


16. The DNA formed as a result of replication has two new strands. (p. 509) A. True
B. False


17. DNA uses RNA to control protein synthesis. (pp. 511-513) A. True
B. False


18. Transcription is making an RNA molecule that is complementary to a portion of another RNA molecule. (p. 512) A. True
B. False


19. Following transcription and processing, RNA moves into the cytoplasm. (p. 512) A. True
B. False


20. Each three-letter unit of an mRNA molecule is called a ______. (p. 513) A. transposon
B. intron
C. codon
D. interferon
E. exon


21. During translation, the order of the codons in mRNA determines the order of the amino acids in a polypeptide. (p. 512) A. True
B. False


22. The portions of the gene that are expressed are the _________. (p. 512) A. transposons
B. introns
C. neurons
D. interferons
E. exons


23. mRNA only contains exons when it leaves the nucleus. (p. 512) A. True
B. False


24. mRNA is transcribed in the cytoplasm. (p. 512) A. True
B. False


25. Translation requires _______. (pp. 512-513) A. transfer RNA
B. ribosomal RNA
C. synthetase tRNA
D. an enzyme to join amino acids together by means of a peptide bond
E. all of the above


26. Proteins are synthesized at the _______. (p. 513) A. nucleus
B. ribosomes
C. mitochondria
D. Golgi body
E. plasma membrane


27. Transfer RNA molecules bring amino acids to the ______. (p. 513) A. nucleus
B. endoplasmic reticulum
C. ribosomes
D. mRNA
E. plasma membrane


28. Transfer RNA has a/an ______ complementary to a mRNA codon. (p. 513) A. anticodon
B. intron
C. codon
D. interferon
E. exon


29. Ribosomal RNA is produced in the _________. (p. 513) A. ribosome
B. mitochondrion
C. nucleolus
D. Golgi body
E. vacuole


30. Ribosomes are composed of rRNA and many different types of _______. (p. 513) A. carbohydrates
B. proteins
C. fats
D. sugars
E. nucleic acids


31. The steps in polypeptide synthesis include _________. (pp. 514-515) A. initiation
B. elongation
C. termination
D. all of the above


32. The order of amino acids in a polypeptide is directly determined by the linear sequence of codons of the ______ . (p. 515) A. tRNA
B. mRNA
C. rRNA
D. protein


33. Several ribosomes are called a ______. (p. 515) A. polypeptide
B. ribose
C. deoxyribose
D. polyribosome
E. mRNA molecule


34. Each group of ______ base(s) on DNA stands for an amino acid. (p. 516) A. one
B. two
C. three
D. four
E. five


35. Triplet codons in mRNA are complementary to the triplet DNA code. (p. 516) A. True
B. False


36. ______ control occurs in the nucleus to control which genes are transcribed and the rate of transcription. (p. 517) A. Transcriptional
B. Posttranscriptional
C. Translational
D. Posttranslational
E. Terminal


37. ______ control occurs in the nucleus after DNA is transcribed and mRNA is formed. (p. 517) A. Transcriptional
B. Posttranscriptional
C. Translational
D. Posttranslational
E. Terminal


38. A ______ gene codes for a repressor protein. (p. 518) A. promoter
B. operator
C. structural
D. regulator
E. transcription


39. The promoter is ___________. (p. 518) A. a short sequence of DNA where the repressor binds, preventing RNA polymerase from attaching to the promoter
B. a short sequence of DNA where RNA polymerase first attaches when a gene is to be transcribed
C. one to several genes of a metabolic pathway that are transcribed as a unit
D. a gene that codes for a repressor protein
E. any dominant gene


40. Each cell contains a full complement of genes but due to the activity of the ______ only certain genes are active at any one time. (p. 518) A. promoter
B. operator
C. regulator gene
D. structural gene
E. dominant gene


41. A regulator gene located inside the operon codes for a promoter protein that can bind to the operator and switch on the operon. (p. 518) A. True
B. False


42. The operon model explains a means of transcriptional control in prokaryotes. (p. 518) A. True
B. False


43. Gene mutations are always loss of genetic information. (p. 520) A. True
B. False


44. ______ are specific DNA sequences that have the ability to move within and between chromosomes. (p. 520) A. Exons
B. Transposons
C. Introns
D. Operons


45. Ordinarily, cells with damaged DNA undergo ______ or programmed cell death. (p. 522) A. apoptosis
B. tumor-suppression
C. differentiation
D. angiogenesis
E. metastasis


46. Cancer cells exhibit uncontrolled and disorganized growth. (p. 522) A. True
B. False


47. ______, or the formation of new blood vessels, is required to bring nutrients and oxygen to cancerous tumors. (p. 522) A. Apoptosis
B. Tumor-suppression
C. Differentiation
D. Angiogenesis
E. Metastasis


48. Cancer cells cannot enter the cell cycle and therefore are mortal. (p. 522) A. True
B. False


49. ______ are cancer-causing genes. (p. 525) A. Metastases
B. Mutagens
C. Carcinogens
D. Oncogenes
E. Homozygous recessive genes


50. A cell contains many ___________ where one mutation can cause them to become oncogenes. (p. 525) A. metastases
B. tumor-suppressor
C. benign tumors
D. proto-oncogenes
E. carcinogens


51. Proto-oncogenes promote the cell cycle and _____ genes inhibit the cell cycle. (p. 525) A. recessive
B. tumor-suppressor
C. benign
D. proto-oncogenes
E. carcinogens
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