Chapter 6: DNA, The Molecule of Life
Module 6.1. DNA is a polymer of nucleotides.
1. The molecule of heredity is .
2. Which of the following is used to construct DNA?
A) |_| chromosomes
B) |_| nucleotides
C) |_| double helix
D) |_| carbohydrates
3. Create double stranded DNA, by filling in the complementary bases:
4. Match the following terms with their appropriate descriptions: double helix, nucleic acid, nucleotide, backbone.
A) Molecules that contain information to make proteins
B) Consists of a base, five-carbon sugar, and a phosphate
C) Structure of a double-stranded molecule of DNA
D) Identical among all DNA molecules
5. Complete the following diagram of a nucleotide with the terms: phosphate group, sugar group, base group:
6. Overall, a molecule of DNA has a negative charge. Which component of DNA gives it this charge?
7. A gene is a specific section of DNA that contains the instructions to make a protein. If all molecules of DNA contain a phosphate group, a deoxyribose, and a base, propose an explanation for how the information to make a protein is coded within the DNA molecule.
8. If thymine makes up 20% of the bases in a DNA double helix, what percentage of the bases is guanine?
A) |_| 80%
B) |_| 60%
C) |_| 30%
D) |_| 20%
Module 6.2. During DNA replication, a cell duplicates its chromosomes.
9. If one polynucleotide strand of DNA has ACTTGACTAGCTA as its sequence of bases, what would be the sequence of bases on the opposing strand?
10. True or False; If false, make a true statement: DNA must be precisely copied prior to being passed on to the next generation
11. The process by which a molecule of DNA is copied is known as .
12. Complete the following diagram, which illustrates the nature of DNA replication. Use the following terms: parent double-stranded DNA, daughter double-stranded DNA, template strands, newly synthesized strands. Note some terms may be used more than once.
13. The following diagram uses colors to illustrate the replication of a chromosome. Use your knowledge of DNA replication to determine whether or not the illustration is accurate. If it is not accurate, briefly explain how to make it correct.
14. Place the following steps of DNA replication in the proper order: DNA fragments are fused together; double helix is pulled apart; new strands of DNA are synthesized.
15. A drug that inhibits DNA ligase but not DNA polymerase is added to a cell. Explain how DNA replication would be affected as a result of this drug.
Module 6.3. DNA directs the production of proteins via RNA.
16. True or False; if false make a true statement: Nucleic acids store the information to make carbohydrates.
17. Two types of nucleic acids that are found in all cells are and .
18. Which of the following is found in all nucleotides?
A) |_| Phosphate group
B) |_| Ribose
C) |_| Deoxyribose
D) |_| Uracil
19. Is the following diagram a nucleotide of DNA, RNA, or could it be either one? Briefly explain your answer.
20. Complete the following table, which compares and contrasts the structures of DNA and RNA.
|Common both DNA and RNA|
21. Certain viruses, like HIV, actually contain RNA. When a virus of this type takes over a host cell, it makes DNA from its RNA. The viral DNA is then used to make an RNA copy, which is used to make viral proteins. In all cells, the flow of genetic information is from DNA RNA proteins. What is the flow of information in viruses (which are not considered cells) like HIV?
22. You are a biochemist and have been given a test tube containing a small amount of nucleic acid. You have been asked to determine whether it is DNA or RNA. Which of the following would be a characteristic that indicates RNA? Hint: There may be more than one correct answer.
A) |_| Presence of uracil, but no thymine
B) |_| Presence of guanine, but no cytosine
C) |_| Presence of phosphate, but no nitrogen
D) |_| Presence of ribose, but no deoxyribose
Module 6.4. Genetic information flows from DNA to RNA to protein
23. True or False; If false, make a true statement: The nucleotide sequence in DNA through the process of information flow comes to produce your characteristics.
24. Correct the following: RNA protein DNA
25. Complete the following diagram, which represents the flow of genetic information in a cell. Use the terms: transcription, translation, DNA, RNA, protein, ribosome, nucleus, cytoplasm, nuclear membrane, nuclear pore. Note that “D” is on the structure behind the arrow, and “E” is on the arrow.
26. Translation converts the information stored in into .
A) |_| DNA; RNA
B) |_| RNA; a protein
C) |_| protein; DNA
D) |_| protein; RNA
27. Briefly explain why you think “mRNA” is a good name for the RNA copy made from DNA.
28. Complete the following table, which compares transcription and translation.
29. If a strand of DNA has the sequence AAGCTC, transcription will result in which of the following?
A) |_| Single RNA strand with the sequence TTCGAG
B) |_| DNA strand with the sequence TTCGAG
C) |_| Single RNA strand with the sequence UUCGAG
D) |_| DNA strand with the sequence AAGCTC
30. A series of three nucleotides that specifies an amino acid is a(n) .
31. A student is given a sequence of DNA as follows: AACTAGCTAGCT, and is asked to provide the mRNA copy that would be made from that sequence during transcription. The student provides the following sequence: TTGATCGATCGA. Is this the correct sequence? If not, explain why it is incorrect and fix it.
Module 6.5. Transcription creates a molecule of RNA from a molecule of DNA
32. is the process by which information stored in DNA is copied into mRNA.
33. List the following steps of transcription in order: RNA polymerase makes RNA; mRNA leaves the nucleus; RNA polymerase binds the promoter; RNA splicing.
34. Complete the following diagram, which illustrates the process of transcription. Use the terms: DNA polymerase, promotor, DNA
35. The template strand is the DNA strand directly used by the RNA polymerase to make the RNA copy. You are given the following mRNA sequence: AUGCUGAUU. Are you able to determine the sequence of bases on the DNA strand that was not transcribed? Briefly explain your answer either way. (Note: DNA is double stranded. During replication it is unwound and only one strand serves as the template strand. You are being asked if you can determine the sequence of the non-template strand).
36. A gene has a sequence of DNA in front of it that directs the RNA polymerase where to begin transcription. This sequence of DNA is the:
D) |_|RNA splicing
37. You are a graduate student at the University of Iowa and working as a teaching assistant for a freshman introductory biology course. Two of your students have come to you with a question about the sequence of an mRNA transcribed from a gene. The original DNA sequence from which the mRNA was transcribed reads: TGACGATCGTA. The students were asked to provide the sequence of bases in the mRNA and came up with the following mRNA sequence: ACTGCTAGCAT. They are confused because their answer does not match the answer in the book. Briefly explain the very common mistake they made and what the correct sequence would be.
38. True or False; If false, make a true statement: The terminator is the sequence of DNA in front of the gene that tells the RNA polymerase where to begin transcription.
39. List three ways in which mRNA is modified after transcription:
40. Are introns and exons found in DNA or RNA?
Module 6.6. Translation involves the coordination of three kinds of RNA.
41. True or False; If false, make a true statement: The process of translation occurs within the cytoplasm on a cellular structure known as the mitochondrion.
42. Which of the following RNA molecules is a component of ribosomes?
A) |_| mRNA
B) |_| rRNA
C) |_| tRNA
D) |_| All of the above
43. A set of three nucleotides that specifies an amino acid is called a(n) .
44. Which of the following RNA molecules is involved in the process of translation?
A) |_| mRNA
B) |_| rRNA
C) |_| tRNA
D) |_| All of the above
45. Complete the following diagram, which illustrates a ribosome:
46. Complete the following table, which compares the different kinds of RNA.
47. Briefly explain why a molecule of tRNA makes a good translator during the process of translation. Be sure to use the terms codon, anticodon, amino acid.
48. According to the table of the genetic code shown here, changing the second base of the codon
A) |_| always changes the amino acid that is encoded.
B) |_| never changes the amino acid that is encoded.
C) |_| sometimes changes the amino acid that is encoded.
D) |_| changes all of the above as noted.
49. What codon does every mRNA molecule have in common? What amino acid begins every polypeptide? Use the chart below:
50. Match the description to the molecule(s). Each choice should be used only once.
D. More than one of the above.
E. None of the above.
A molecule of this will always have an equal percentage of A and G, and an equal percentage of C and T
Has an anticodon and carries an amino acid
Serves as a messenger for taking genetic information from the nucleus to the cytoplasm
Is involved in the process of translation
Is a component of ribosomes
51. How many codons are in the following mRNA sequence:
52. Use the information from question 49 to determine how many amino acids would be in the polypeptide produced from that mRNA.
Module 6.7. Translation creates a molecule of protein via the genetic code
53. True or False; If false, make a true statement: Ribosomes are part of the cytoplasm.
54. Place the following steps of translation in order: elongation, termination, initiation.
55. Translation takes place in the ______ on a _________.
A) |_| nucleus; ribosome
B) |_| cytoplasm; ribosome
C) |_| nucleus; mitochondria
D) |_|cytoplasm; lysosome
56. A drug that changes the AUG codon to UAC would most likely have what effect on translation? Be brief but specific in your answer.
57. If three DNA bases of the template strand are AGT, what is the anticodon of the tRNA that brings the amino acid?
A) |_| UCA
B) |_| TCU
C) |_| AGU
D) |_| TCA
58. Complete the following table, which compares the different stages of translation.