1. Cells of all multicellular organisms arise during mitosis from a single cell known as a(n)
A) gamete. B) zygote. C) embryo. D) clone. E) fetus.

2. Repressor proteins
A) prevent binding of RNA polymerase to DNA. B) can be inactivated by an inducer (lactose). C) provide negative control D) prevent binding of RNA polymerase to DNA and can be inactivated by an inducer such as lactose. E) prevent binding of RNA polymerase to DNA. can be inactivated by an inducer such as lactose, and provide negative control.

3. During genetic modification,
A) a prokaryote is changed into a eukaryote. B) a cell takes in DNA from another source. C) a cell’s own DNA is inserted into a plasmid. D) a cell is mutated.

4. What does the figure to the right show?
A) gel electrophoresis B) DNA sequencing C) a restriction enzyme producing a DNA fragment D) polymerase chain reaction

5. Which of the following is the region that is the binding site for RNA polymerase?
A) heterogeneous nuclear DNA B) repressor gene C) promoter sequence D) operator sequence E) all of these

6. Probes for cloned genes use
A) complementary nucleotide sequences labeled with radioactive isotopes. B) certain media with specific antibodies. C) specific enzymes. D) certain bacteria sensitive to the genes. E) all of these

7. When a gene transcription occurs, which of the following is produced?
A) more DNA B) protein or polypeptide sequences C) messenger RNA D) enzymes E) genetic defects

8. The DNA fragments produced by automated DNA sequencing are identified using
A) radioactive probes. B) laser beams. C) ultracentrifugation. D) electron microscopy. E) restriction enzymes.

9. The laboratory technique used to separate the DNA fragments produced by automated DNA sequencing is
A) the polymerase chain reaction. B) gel electrophoresis. C) ultracentrifugation. D) electron microscopy. E) fluorescence microscopy.

10. The lactose operon includes
A) an operator. B) three structural genes that manufacture lactose-metabolizing enzymes. C) a promoter. D) a repressor. E) an operator, three structural genes that manufacture lactose-metabolizing enzymes, and a promoter.

11. What is the name of the process in which a molecule combines with a repressor protein and changes the shape of the protein so that it no longer binds to the operator sequence?
A) induction B) corepression C) repression D) translation E) transcription

12. One function of gel electrophoresis is to
A) separate DNA fragments. B) cut DNA. C) recombine DNA. D) extract DNA.

13. A promoter is a
A) binding site for RNA polymerase. B) binding site for DNA polymerase. C) start signal for transcription. D) stop signal for transcription.

14. What kind of cell (or cells) are used to make animal clones?
A) body cell only B) egg cell only C) egg cell and sperm cell D) body cell and egg cell

15. Enzymes used to cut DNA molecules in recombinant DNA research are
A) ligases. B) restriction enzymes. C) transcriptases. D) DNA polymerases. E) replicases.

16. If two DNA samples showed an identical pattern and thickness of bands produced by gel electrophoresis, the samples contained
A) the same amount of DNA. B) fragments of the same size. C) the same DNA molecules. D) all of the above

17. A repressor protein binds with
A) messenger RNA. B) the operator. C) the regulator. D) a product. E) a substrate.

18. In a negative control system over gene expression
A) initiation of transcription is promoted by a regulatory protein binding to DNA. B) an inducer promotes transcription. C) inhibitor proteins unblock the promoter. D) the promoter is missing.

19. To produce genetically engineered bacteria that make a human protein, which of the following steps does a scientist have to take first?
A) Insert the human gene for the protein into a plasmid. B) Extract the protein from the bacterial culture. C) Use a restriction enzyme to cut out the gene from human DNA. D) Transform bacteria with the recombinant plasmid.

20. In negative control systems, which of the following would cause transcription to proceed?
A) repressor B) operator C) cooperator D) inducer E) DNA

21. When E. coli do not have a supply of lactose,
A) lactose molecules bind to the repressor. B) the repressor binds to the operator of the lac operon. C) RNA polymerase binds to the promoter of the lac operon. D) the lac genes are transcribed.

22. Molecules that interact with DNA to alter gene expression are
A) operons. B) promoters. C) regulatory proteins. D) repressor amines. E) carbohydrates.

23. The process of DNA fingerprinting is based on the fact that
A) the most important genes are different among most people. B) no two people, except identical twins, have exactly the same DNA. C) most genes are dominant. D) most people have DNA that contains repeats.

24. The obvious advantage of the lactose operon system is that
A) lactose is not needed as energy for bacteria. B) lactose-metabolizing enzymes need not be made when lactose is not present. C) the bacteria will make lactose only in the presence of the proper enzymes. D) milk is not needed for adult humans' diet. E) glucose can substitute for lactose in the diet of intolerant persons.

25. In E. coli, the lac operon controls the
A) breakdown of lactose. B) production of lactose. C) breakdown of glucose. D) production of glucose.

26. A regulator gene produces which of the following?
A) repressor protein B) regulatory enzyme C) promoter D) operator E) transcriber

27. Restriction enzymes
A) often produce staggered cuts in DNA that are useful in splicing genes. B) are like most enzymes in being very specific in their action. C) are natural defense mechanisms evolved in bacteria to guard against or counteract bacteriophages. D) are used along with ligase and plasmids to produce a DNA library. E) all of these

28. Which term describes processes by which cells with identical genotypes become structurally and functionally distinct from one another?
A) metamorphosis B) metastasis C) cleavage D) differentiation E) induction

29. Which of the following steps is NOT essential in producing recombinant DNA?
A) Cut out a piece of DNA from a DNA molecule. B) Splice a piece of DNA into DNA from another organism. C) Use a restriction enzyme to form sticky ends in DNA. D) Read the DNA sequence of the piece of DNA to be cut and spliced.

30. Genes located in different regions of the body during embryonic development may be
A) turned on and off. B) never turned on. C) turned on and left on. D) activated for only a short time in one cell and a long time in another cell. E) all of these

31) Proteins that bind to DNA and turn on operons by making it easier for RNA polymerase to bind to a promoter are called
A) inhibitors. B) activators. C) repressors. D) operators. E) regulators.

32) The following are the results of a PCR-based DNA fingerprinting analysis done at two different loci on blood found at a grisly crime scene. Lane V shows the victim's blood, lane S shows the blood sample from the crime scene, and lanes A through D show blood from four suspects. Which suspect is undoubtedly the killer?
A) A B) B C) C D) D E) none of these

33) The enzymes used to cut genes in recombinant DNA research are called
A) RNA polymerases. B) spliceosomes. C) restriction enzymes. D) replicases. E) DNA polymerases.

34) Manipulating the molecular basis of inheritance by recombinant DNA technology is called
A) the polymerase chain reaction (PCR). B) DNA fingerprinting.
C) restriction fragment length polymorphism (RFLP). D) biotechnology.
E) Mendelian genetics.

35) Nucleic acid probes are used to ______.
A) find a specific nucleotide sequence B) synthesize a DNA strand complementary to a sticky end
C) destroy clones that do not carry the recombinant plasmid of interest D) isolate bacterial genes E) create sticky ends

36) Restriction enzymes are useful in recombinant DNA studies because they
A) can separate pieces of DNA and RNA from each other. B) join the cut ends of small DNA molecules.
C) cut DNA at specific locations. D) can reproduce in bacteria. E) give plasmids antibiotic properties.

37) How is it that the cells in different body tissues are able to perform different functions?
A) The cells exhibit different patterns of gene expression. B) The cells contain different genes.
C) The nutrient preferences of particular tissues play a role. D) The age of the cells making up the tissues plays a role. E) The mutations that have accumulated in the cells of the different tissues control functions.

38) During the process of electrophoresis, the ________ functions like a thick filter, separating the samples according to their size.
A) negatively charged electrode B) sample well C) gel D) sample mixture E) positively charged electrode

39) Which of these statements can be logically inferred from the amount of DNA shared by chimpanzees and humans?
A) Humans and chimpanzees share a relatively recent common ancestor.
B) Humans are a more complex life form than chimpanzees.
C) Humans are unique and different from all other life forms.
D) Humans have many more genes than chimpanzees do.
E) Humans evolved from chimpanzees.

40) Gel electrophoresis separates DNA fragments on the basis of differences in their ______.
A) pH B) A:C ratio C) degree of hydration D) length E) G:T ratio

41) Biotechnology CANNOT be used to
A) identify human fetuses with particular genetic diseases. B) alter any of the traits levels of newborn infants.
C) produce effective and safe vaccines. D) produce large quantities of particular human proteins. E) alter food plants to increase yield.

42) 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.

43) Approximately what percentage of human DNA is noncoding?
A) 49% B) 79% C) 37% D) 98.5% E) 100%

44) Which of the following turns off transcription by binding to the operator?
A) repressors B) lactose C) enzymes D) promoters E) RNA polymerase

45) The human genome contains approximately ______ genes.
A) 50,000-60,000 B) 30,000 C) 1,000-2,000 D) 2,000-3,000 E) 500

46) Goals of genetic engineering include all of the following EXCEPT
A) to provide economic and social benefits. B) to learn more about genetic inheritance. C) to learn more about enetic diseases. D) to learn more about bacterial inheritance. E) All of the above are goals of genetic engineering.

47) Which of the following pieces of evidence would be considered the best for establishing biological relatedness?
A) pictures from family reunions B) legal documents C) a very close match in the DNA profile
D) testimony from relatives E) birth certificates

48) In order to join a fragment of human DNA to bacterial or yeast DNA, both the human DNA and the bacterial (or yeast) DNA must be first treated with the same
A) restriction enzyme. B) DNA gyrase. C) DNA polymerase. D) DNA ligase. E) none of the above

49) Restriction enzymes
A) cut DNA at specific sites. B) bind together strands of DNA. C) edit proteins. D) bind RNA fragments together. E) stop transcription.

50) Which of the following is NOT a goal of biotechnology?
A) creating humans with higher intelligence levels B) efficiently producing biologically important molecules
C) improving agriculturally important food plants D) more effectively treating disease
E) generating economic benefits

51) Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.
A) RNA transcriptase B) nucleosome packing C) intron segments D) regulatory proteins E) DNA ligase

52) Bacterial RNA polymerase binds to the ______.
A) operator B) promoter C) regulatory gene D) proto-oncogene E) exon

53) Which of the following permits a single gene to code for more than one polypeptide?
A) genetic differentiation
B) alternative RNA splicing
C) retention of different introns in the final version of the different mRNA strands
D) protein degradation
E) addition of different types of caps and tails to the final version of the mRNA strands

54) In biotechnology research, DNA fragments created by restriction enzyme action are separated from one another by
A) crossing over. B) filtering. C) centrifugation. D) the polymerase chain reaction. E) gel electrophoresis.

55) Ethical dilemmas raised by DNA technology and knowledge of the human genome include ______.
A) the safety of GM foods B) the potential discrimination against people predisposed to certain diseases
C) the appropriateness of creating new plants, animals, and microorganisms D) the potential for interfering in evolution E) all of the above

56) What is a difference between embryonic and adult stem cells?
A) It is easier to enucleate embryonic stem cells. B) Embryonic stem cells are harder to isolate than are adult stem cells. C) Adult stem cells are easier to grow in culture. D) The use of embryonic stem cells raises fewer ethical issues than the use of adult stem cells. E) Embryonic stem cells are undifferentiated; adult stem cells are partially differentiated.

57) A DNA fragment with a sticky end that reads -ATTCG will bind with another DNA fragment with a sticky end that reads
A) UAAGC- B) ATTGC- C) GCCTA- D) CGGAT- E) TAAGC-
58) The following figure shows that gel electrophoresis can be used to separate repetitive DNA sequences. Gel electrophoresis separates DNA fragments because ______.

[pic]

A) the DNA fragments have different lengths
B) of the salt concentration in the gel matrix
C) of the consistency of the gel
D) double stranded moves slower than single stranded DNA
E) of ratios of guanine to cytosine

59) Approximately what percentage of the human genome is identical to that of a chimpanzee?
A) 92.0% B) 50.0% C) 62.3% D) 88.5% E) 98.8%

60) The lac operon is shown in the accompanying figure. Identify each of the lettered items.

[pic]

|1B |11A |21B |31B |41B |51D |
|2E |12A |22C |32B |42E |52B |
|3B |13A/C |23B |33C |43D |53B |
|4C |14D |24B |34D |44A |54E |
|5C |15B |25A |35A |45B |55E |
|6A |16C |26A |36B/C |46E |56E |
|7C |17B |27E |37A |47C |57E |
|8B |18B |28D |38C |48A |58A |
|9B |19C |29D |39A |49A |59E |
|10E |20D |30E |40D |50A | |

-----------------------
E

D

C

D

C

B

A