BIOL 111 - EXAM 4 NAME_____________________________

Dr. Brugam - 3/21/97

1. Three forms of RNA used in protein synthesis are

a. aRNA bRNA cRNA c. gRNA mRNA tRNA

b. aRNA mRNA tRNA d. rRNA mRNA tRNA

2. A codon is:

a. A gene.

b. A protein.

c. A sequence of three base pairs that codes for an amino acid.

d. A sequence of three base pairs that codes for mRNA.

3. The gene for human insulin is spliced into a plasmid. The plasmid is inserted

into a bacterium. The bacterium produces human insulin. Is it the same as the insulin you produce?

a. Yes b. No

4. If, in the O.J. Simpson trial, the prosecution showed that there was blood from 3 people at the scene of the crime and none of the blood matched O.J.'s DNA

fingerprint. What is the probability that one of the 3 blood samples came from O.J.?

a. 0% b. 25% c. 50% d. 100%

5. An anticodon is

a. The three base sequence on tRNA that attaches to the mRNA.

b. The three base sequence on the mRNA that attaches to the RNA.

c. The three base sequence on a DNA molecule that codes for a particular amino acid.

6. The genetic code is made up of 3 base pair units which code for amino acids.

a. True b. False

7. In protein synthesis the DNA code is first transcribed to

a. tRNA b. mRNA c. Ribosomes d. Proteins

8. What is the function of ribosomes in cells?

a. They dissolve bacteria.

b. They are the site where respiration is carried out.

c. They function in the assembly of proteins.

d. They package chemicals for export from the cell.

9. The DNA genetic code is the "universal language" of genetics in all living

things.

a. True b. False

10. A man named Nirenberg did an experiment that showed that UUU codes for the amino acid phenylalanine. In this experiment he used an artificially made chemical

called poly-U. He added it to a preparation of ribosomes and got a polypeptide made only of phenylalanine molecules linked together. The poly-U acted as

a. A tRNA b. An energy source c. An mRNA

11. Some of the codons are "stop" codewords which do not code for amino acids, but which cause transcription of the DNA code to mRNA to stop.

a. True b. False

12 Chargaff analyzed the DNA of a number of species. He found that:

a. The DNA of all species has exactly the same base composition percentage.

b. The amount of adenine and thymine are always equal to each other.

c. The amount of adenine and guanine are always equal to each other.

13. 5-fluoro-uracil is a drug used in cancer therapy. It works by:

a. Attaching to the outsides of cancer cells.

b. Substituting for uracil in the RNA of all growing cells in the body.

c. Causing hair to fall out.

d. Causing the immune system to destroy the cancer.

14. If the amino acid sequence of a protein is changed, what may happen?

a. The protein will not be produced.

b. The protein will not function as it is supposed to.

c. The protein will be over-produced.

15. A "change in the base sequence of the gene" is a definition of:

a. Dominance b. Test cross c. Mutation d. Sex-linked inheritance

16. Bacteria like E.coli have a single long circular chromosome and smaller rings of DNA called

a. Protons b. Operons c. Plasmids d. Operators

17. Restriction endonucleases

a. Cut DNA molecules in two. c. Make repressor proteins.

b. Make mRNA. d. Stick DNA molecules together.

18. The substance from tumor cells which changes normal cells to tumor cells is:

a. RNA b. DNA c. Protein d. Lipid

19. Cancer is biologically dangerous because:

a. It poisons the cells of the body.

b. It eats our tissues and body fluids.

c. It is highly contagious.

d. Its rapid growth is physically damaging to a complex animal.

20. What is a metastasis?

a. A recombinant DNA organism.

b. A kind of plasmid.

c. A secondary tumor formed by migrating tumor cells.

d. A particular chemotherapy agent.

21. A major difference between normal and cancer cells is that normal cells undergo carefully controlled cell divisions, but cancer cells divide in uncontrolled fashion.

a. True b. False

22. Changing the amino acid sequence of a protein primary structure will never have any effect on the functioning of the protein.

a. True b. False

23. Cancer rates in humans may increase by

a. No means known to man. We don't know the cause of cancer.

b. Treatment with x-rays.

c. Almost any external treatment.

d. Most things which effect pregnant females.

24. Currently, genetic engineering involves

a. The direct manipulation of genetic material (DNA) in plants, animals and bacteria.

b. The production of life from dead chemicals.

c. The improvement of the human race.

d. The formation of "monsters".

25. Carcinogenic substances are in general not mutagenic.

a. True b. False

26. The "oncogene theory" says that cancer is caused by activation of normal genes present in the cell.

a. True b. False

27. Ligases are enzymes that cut DNA molecules in two.

a. True b. False

28. Mutagens cause cancer. How?

a. They are viruses that transmit cancer. c. They break DNA.

b. They thin the blood. d. They reduce hormone levels.

29. The base uracil is found in

a. DNA only b. RNA only c. Both DNA and RNA d. Proteins

30. A gene is a complete turn in a double helix.

a. True b. False

31. How many dots are in the bottom left-hand corner of this page?

a. One b. Two