Choose the response which best answers the question or completes the statement. 

1. The genetic specifications for assembling a protein are in the DNA. The first step in protein 
    synthesis is for that code to be: (1.) transcribed to tRNA (2.) transcribed to mRNA
    (3.) translated to tRNA (4.) translated to mRNA

2. Which molecule hauls amino acids to the ribosomes? (1.) rRNA (2.) tRNA 
     (3.) DNA (4.) mRNA

3. Which is found in RNA but not in DNA? (1.) adenine (2.) cytosine (3.) guanine (4.) uracil
                                                                   (5.) phosphate groups

4. Which of the following is TRUE of tRNA?
(1.) It functions in carrying the code from messenger RNA from the nucleus to the ribosomes.
(2.) It consists of a single strand of nucleotides.
(3.) It is necessary for translation.  (4.) all of the previous are true statements

5. Which statement about DNA is false?
(1.) The sugar in DNA has one less oxygen molecule than that in RNA.
(2.) DNA is a double stranded molecule.
(3.) In DNA, the base uracil replaces thymine.
(4.) DNA is a polymer made of nucleotide subunits.

6. The process of synthesizing mRNA along a DNA template is called
(1.) transcription (2.) translation (3.) transformation (4.) translocation (5.) crossing over

In questions 7 and 8 below, a segment of DNA has one strand with the following sequence of bases.
A G C G C A T A G C A A

7. The complementary strand of DNA is
(1.) U C G C G U A U C G U U
(2.) T C G C C G A T C G T T
(3.) T C G C G T A T C G T T
(4.) T C G C A T T A C A U U
(5.) T C G W R O N G A C U U

8. The mRNA molecule coded for by the original strand is
(1.) T C G C G T A T C G T T
(2.) U C G C G U A U C G U U
(3.) T C A C M R N A T C C C
(4.) U A C A T T U C A G G G
(5.) U C G G C A T T U G G C

9. Which is true of a codon?
(1.) It consists of 64 nucleotides.
(2.) It may code for the same amino acid as another codon does.
(3.) It never codes for more than one amino acid.
(4.) It extends from one end of a tRNA molecule
(5.) It is the basic unit of the genetic code.

10. Which structure is coded for by the shortest (or smallest) sequence of DNA?
(1.) a tRNA having 75 nucleotides
(2.) a mRNA having 75 codons
(3.) a polypeptide composed of 75 amino acids
(4.) a protein composed of 2 polypeptides, each 35 amino acids long

11. The nucleotides in DNA are grouped in triplets, or 3-letter words.
      The number of 3-letter words that can be made from the DNA nucleotides is
     (1.) 64 (2.) 16 (3.) 20 (4.) 46

12. In what direction can a DNA polymerase work when catalyzing the addition of nucleotide
monomers to build a strand of DNA?
(1.) from the 5' toward the 3' end of the new strand being assembled
(2.) from the replication centers in two directions called replication forks
(3.) from the 3' to the 5' end of the strand being assembled
(4.) in both directions if DNA ligase is present

13. The DNA of all organisms replicates by (1.) dispersive replication (2.) reverse replication
(3.) semi-conservative replication (4.) conservative replication

14. The scientist(s) most associated with the currently accepted theory of DNA replication is (are) (1.) Darwin and Lamarck (2.) Griffith and Wilkins (3.) Meselson and Stahl (4.) Cartwright and Davis

15. The two sides of the DNA molecule are held together at their bases by:
(1.) covalent bonds (2.) peptide bonds (3.) James Bonds (4.) ionic charges (5.) hydrogen bonds

16. The three parts of a nucleotide are held together by (1.) ionic bonds (2.) covalent bonds
(3.) van der Waals forces (4.) hydrogen bonds (5.) James Bonds

17. The technology that finally clarified the structure of DNA was (1.) autoradiography
(2.) ultracentrifugation (3.) electron microscopy (4.) X-ray diffraction (5.) gel electrophoresis

18. Fred Griffith was able to determine that (1.) DNA was the genetic material
      (2.) replication was semi-conservative (3.) genetic capabilities could be transferred between bacteria
      (4.) viruses consist of RNA and proteins (5.) DNA would undergo mutation

19.  What kind of bond joins the complementary nucleotides?  (1.) ionic bonds  (2.) nitrogenous bases
       (3.) strands of RNA   (4.) covalent bonds   (5.) hydrogen bonds

20. By estimating the relative quantity of adenine, guanine, cytosine, and thymine in the DNA
      of various cells, Chargaff played an important role in clarifying the:
      (1.) genetic code (2.) structure of DNA (3.) mechanism of translation (4.) chemistry of RNA
      (5.) principle of base-pairing

21. The actual assembly of amino acids into protein occurs on the
       (1.) endoplasmic reticulum (2.) ribosomes (3.) tRNAs (4.) golgi bodies (5.) none of these

22. To read the genetic code, the bases of DNA or RNA are placed in groups of
       (1.) 1 (2.) 4 (3.) 6 (4.) 8 (5.) none of these

23. The total number of codons possible in the code system is: (1.) 4 (2.) 16 (3.) 32 (4.) 64 (5.) none of these

24. Which remains in the nucleus during translation? (1.) tRNA (2.) mRNA (3.) rRNA (4.) all of these 
      (5.) none of these

25. Which does NOT represent a difference between RNA and DNA?
      (1.) RNA is single stranded.
      (2.) RNA contains the sugar ribose.
      (3.) RNA utilizes nucleotides in its structure.
      (4.) RNA substitutes uracil for thymine.
      (5.) All of the above represent differences between DNA and RNA.

26. Which represents a similarity between DNA and RNA?
      (1.) Double-stranded helical structure
      (2.) The presence of uracil
      (3.) The same number of oxygen atoms in each of their pentose sugars
      (4.) Nucleotides consisting of a phosphate, sugar, and nitrogenous base
      (5.) The relative length of each molecule is similar

27. Research by biologists such as Beadle and Tatum has led to the now questioned hypothesis that the 
      synthesis of each protein (enzyme) in a cell is governed by the action of a single
      (1.) gene (2.) chromosome (3.) nitrogenous base (4.) phosphate molecule

28. The coded information in a DNA molecule directly determines the formation of
      (1.) polypeptides (2.) polysaccharides (3.) lipids (4.) glycerol (5.) monosaccharides

29. The S form of pneumococcus causes the disease pneumonia in mice, while the R form
      does not. The series of experiments on the R and S forms of pneumococcus led to the
      1944 discovery by Avery, McLeod, and McCarty that
      (1.) both R and S forms could cause pneumonia
      (2.) S cells had DNA, but R cells did not
      (3.) R cells could be transformed by phage
      (4.) the transforming factor for R cells is DNA

30. Electrophoresis is used to (1.) amplify small DNA samples to obtain enough
      for analysis (2.) clone genes (3.) match a gene with its function (4.) cut DNA
      into fragments (5.) separate fragments of DNA

31. DNA fingerprints used as evidence in a murder trial look something like
      supermarket bar codes. The pattern of bars in a DNA fingerprint shows
      (1.) the order of genes along particular chromosomes (2.) the presence
      of various-sized fragments of DNA (3.) the exact location of a specific gene in
      a genomic library (4.) the presence of dominant or recessive alleles for
      particular traits (5.) the order of bases in a particular gene

32. The immediate goal of the Human Genome Project is to (1.) Develop new technologies
      for studying DNA (2.) compare the genomes of a large number of individuals
      from different parts of the world (3.) map and sequence the genomes of
      important research organisms such as Drosophila melanogaster (4.) map all
      the human genes and determine the nucleotide sequence of the entire human
      genome (5.) find cures for human genetic disorders

33.  The deoxyribo part in the name deoxyribonucleic acid refers to the (1.) rungs of the sugar ladder 
       (2.) bonds that hold the two strands together (3.) sugar component of DNA (4.) type of helical arrangement

34. Which of the statements about electrophoresis is FALSE? (1.) The process
      requires an electric current. (2.) This technique can be used to separate
      charged molecules. (3.) Large molecules migrate more slowly in the
      agarose gel than small molecules. (4.) The technique can be used to easily
      separate nonpolar molecules.

35. A nucleotide of DNA could contain (1.) adenine, ribose, and phosphate (2.) nitrogenous base, phosphate, and glucose 
      (3.) phosphate, deoxyribose, and thymine (4.) uracil, deoxyribose and phosphate

36. In recombinant DNA experiments,______ is used to cut pieces of DNA and
      ______ joins the resulting fragments to form recombinant DNA.
      (1.) a transposon . . . a restriction enzyme (2.) a transposon . . . a plasmid
      (3.) DNA ligase . . . a restriction enzyme (4.) a plasmid . . . DNA ligase
      (5.) a restriction enzyme . . . DNA ligase

42. Which are arranged in the correct order by size, from largest to smallest?
      (1.) chromosome - gene - nucleotide - codon  (2.) chromosome - gene - codon - nucleotide
      (3.) codon - chromosome - gene - nucleotide  (4.) nucleotide - chromosome - gene - codon
      (5.) gene - chromosome - codon - nucleotide

46. During the process of translation (polypeptide synthesis), ____ matches
      an mRNA codon with the proper amino acid. (1.) DNA polymerase
      (2.) transfer RNA (3.) a ribosome (4.) messenger RNA (5.) GTP

47. Each nucleotide in a DNA molecule is composed of  (1.) a nitrogenous base and a 
      phosphate group  (2.) a sugar called ribose, a nitrogenous base, and a phosphate group  
      (3.) a sugar called deoxyribose, a nitrogenous base, and a phosphate group  (4.) a sugar 
      called deoxyribose and a phosphate group  (5.) deoxyribose and a nitrogen base.

48. The bases on one strand of DNA are CTAGAAC. The complementary section on the other strand of 
      DNA is  (1.)  CTAGAAC  (2.) AGCTCCA  (3.) GATCTTG   (4.) TCGAGGT  (5.) GUTCTTG.

49. Covalent bonds between the nucleotides of new DNA strands are formed by enzymes called
      (1.) pyrimidines  (2.) purines   (3.) nucleotides  (4.) transforming factors  (5.) DNA polymerases.

50. DNA replication occurs, ensuring that cells in a multicellular organism carry the same genetic information.
      (1.) in a few hours   (2.) slowly   (3.) before a cell divides   (4.) after completed cell division

51. Each gene minimally dictates the production of one  (1.) chromosome   (2.) codon
      (3.)  tRNA  (4.) DNA strand   (5.) polypeptide. 

52. Transcription is the process of converting a nucleotide sequence of DNA into  
      (1.) a single strand of RNA   (2.) a double strand of RNA   (3.) a single complementary helix of DNA.
      (4.) protein   (5.) polypeptides.

53. The conversion of a sequence of RNA nucleotides into a sequence of amino acids is called
      (1.) transcription   (2.) replication  (3.) RNA splicing  (4.) translation   (5.) mutation.

54. mRNA directs the building of proteins through a sequence of  (1.) introns   (2.) codons. 
      (3.) exons   (4.) anticodons   (5.) proteins

55. The RNA molecule used during transcription is  (1.) transfer RNA  (2.) ribosomal RNA
      (3.) transcription RNA   (4.) messenger RNA  (5.) polymerase RNA.

56. The codons of mRNA are translated to amino acids by
      (1.) translation RNA   (2.) transcription RNA  (3.) transfer RNA.  (4.) messenger RNA.
      (5.) ribosomal RNA.

57. Any change in a nucleotide sequence of DNA is called   (1.) mutagen   (2.) replication
      (3.) duplication   (4.) splicing  (5.) mutation 

58.  Rejoining DNA fragments from two organisms is best known as  (1.) conjugating DNA
       (2.) mapping genes  (3.) recombinant DNA technology  (4.) gene sequencing 

59.  The gene-cutting tools of recombinant DNA technology are  (1.) helicases  (2.) DNA ligases 
       (3.) DNA vectors  (4.) plasmids   (5.) restriction enzymes 

Questions 60 and 61 refer to information in the table of codons. 

Link to the table of codons

60. A single substitution in the third position would have the greatest probability of mutational effect on the 
      codon   (1.) GUU   (2.) AUU   (3.) CGU   (4.) AUG   (5.) CCC 

61. Which amino has the greatest number of codons?   (1.) Leucine (leu)  (2.) Proline (pro) 
      (3.) Tryptophan (trp)  (4.) Glutamic acid (glu)   (5.) Asparic acid (asp) 

62. The "one gene one protein " theory can be explained how genes control in cells by 
      (1.) determining polypeptide chains   (2.) interacting with proteins in the chromosomes 
      (3.) assorting independently during meiosis   (4.) inhibiting enzyme formation in some cell reactions 
      (5.) replicating before the beginning mitosis 

63. Point mutations  (1.) remain in the parent and cannot be passed on to the offspring 
      (2.) occur at the 5' end of a DNA strand   (3.) forces the genetic code to be read from the wrong point 
      (4.) are caused by a break in the chromosome   (5.) result when one nucleotide is changed for another 

Use the diagram of a technique in molecular biology and your knowledge of biology to answer questions
64 to 66 that follow.


64.   The technique being used to assess this information is called 
        (1.) human genome determination (2.) karyotyping  
        (3.) transformation  (4.) DNA blotting  (5.) electrophoresis

65.  Based on the indicated position of the wells, the longest DNA fragment in the crime
        scene sample is at position   (1.)  1   (2.) 2   (3.) 3   (4.) 4   (5.) 5

66. Based on the results of this forensic investigation, it is likely that
       the guilty culprit is (1.) Mr. Bean  (2.) Bob  (3.) Ray  (4.)  Tim  (5.) Mr. Rogers

Use the diagram below to assist you in answering questions 67 through 69.

67.  Structure A contains a  (1.) genetic code  (2.) messenger RNA molecule 
       (3.) single nucleotide, only   (4.) small polysaccharide  (5.) male gamete

68.  Structure B represents  (1.) a ribosome  (2.) recombinant DNA 
        (3.) transfer RNA    (4.) a female gamete 

69. The technique illustrated in the diagram is known as   (1.)  cloning
      (2.) protein synthesis  (3.) genetic engineering  (4.) in vitro fertilization 

Correctly complete the statements below .

1. The fact that adenine bonds with thymine and guanine with cytosine provides an
    example of the concept of _______________ base pairing.

2. DNA is a polymer made up of _______________ subunits.

3. The enzyme which cuts a DNA molecule into smaller pieces is called a(n) ___________.

4. The transfer of segments of DNA from one species into another is referred to as
    ______________ technology.

5. A triplet of mRNA is called a(n) _______________.

6. A triplet of tRNA is called a(n) _______________.

7. The currently most accepted theory of DNA replication is that of ________________ replication.

8. A pattern of a single strand of DNA or RNA used in the replication process is called
    a(n) _______________.

9. The currently most accepted theory of DNA replication was supported
    by experimental work completed by _______________ and Stahl.

10. In RNA, the base uracil replaces the base _______________.

11. RNA is a _______________ stranded molecule.

12. The sugar found in the DNA molecule is called _______________.

13. The enzyme _______________ separates the DNA strands thus allowing the replication
      process to occur.

14. The process of forming mRNA from DNA is called _______________.

15. The fact that adenine/thymine and guanine/cytosine are found in relatively equal
      percentages in a cell is a statement of a concept first proposed by _______________.

16. The sequence of DNA which stops the transcription process is called _______________.

17. The _______________ is the region of a DNA strand where the replication process is occurring.

18. The translation of _______________ occurs on the ribosomes of a cell.

19. The total number of possible codons is _____.

20. The fact that frequently several different triplets can code for the same amino acid
      is proof that the genetic code is _______________.

21.  A(n) ______________ is a part of the mRNA as transcribed from the DNA that contains a portion of 
      the information necessary for final gene product.

22.  A(n) ______________ is an intervening or noncoding segment of a gene.

[Short Answer]

1.  Discuss the process of protein synthesis and their possible problems caused a frame shift mutation. 

2.   A portion of a specific DNA molecule consists of the following sequence of nucleotide triplets:

                                                TAC  GAA  CTT  CGG  TCC

             This DNA sequence codes for the following short polypeptide:

                        methionine - leucine - glutamic acid - proline - arginine

a.) Describe the steps in the synthesis of this polypeptide.
b.)  What would be the effect of a deleltion or an addition in one of the DNA nucleotides?
       Explain why this would result in a frameshift mutation.
c.)  What would be the effect of a substitution in one of the nucleotides?   Explain why this is called a point
      mutation.    Give an example in this DNA sequence (or the m RNA made from it) how a point mutation
      may not result in a different protein being synthesized by this organism.  

3.    The diagram below shows a segment of DNA with a total length of 4,900 base pairs.  The arrows indicate reaction sites 
       for two restriction enzymes (enzyme X and enzyme Y).

 (A)   Explain how the principles of gel electrophoresis allow for the separation of DNA fragments.

 (B)   Describe the results you would expect from electrophoretic separation of fragments from the following treatments of the DNA segment above.  Assume that the digestion occurred under appropriate conditions and went to completion.

I.   DNA digested with only enzyme X                                                

II.  DNA digested with only enzyme Y

III. Undigested DNA

 (C) Explain both of the following:

         (1). The mechanism of action of restriction enzymes

         (2). The different results you would expect if a mutation occurred at the recognition site for enzyme Y.

4.   Use the graphic at the left to assist you in answering the following questions. a.)   Describe how the technique shown at the left can be used to make human insulin in bacterial cells such as E. Coli.   Identify the name of this technique. b.)  Describe the process indicated at the left and explain how enzymes such as restriction enzymes and DNA ligase are involved in this process. c.)   List at least three other specific uses for this technique in molecular biology.

5.   Discuss and describe Griffith's bacterial transformation experiment.

Now hopefully the correct answers!

Please send any comments about this practice test to jbuckley@ekcsk12.org