BIOLOGY 3030 Practice EXAM III I. Matching. Pick the best choice ...

BIOLOGY 3030
Practice EXAM III
I. Matching. Pick the best choice. No item is used more than once
____ Substance that enzymes, muscle, antibodies,
hemoglobin, etc are composed of
____ Disease that arises from an inability to metabolize
a sugar derived from milk
____ Disease where individuals cannot repair
DNA damage from sunlight
____ Disease where there is a defect in a receptor
protein that is supposed to bind excess cholesterol
____ Agents that cause non-hereditary errors in fetal
development, affecting gene expression
____ Type of mutation that results from the addition or
deletion of a nucleotide pair
____ Bonds that link amino acids into a chain
____ The synthesis of RNA, using one strand of
the DNA as a template
____ The synthesis of polypeptide, using mRNA
as instructions
____ Type of RNA that carries amino acids to the
sites of protein synthesis
____ Type of RNA that carries the gene's
information to the sites of protein synthesis
____ Structure that provides the sites in cells
where proteins are synthesized
____ That unit which codes for one particular
amino acid
____ That unit which codes for one polypeptide
chain
____ A fundamental principle first stated by Beadle
and Tatum states one gene : one …..
____ Fragile-X syndrome is an example of a
disorder caused by what type of mutation
____ This teratogen may cause severe
learning and behavioral problems
____ Term used to describe the type of mutation
where there is an incorrect amino acid
in the polypeptide chain
____ Term used to describe type of mutation
where a change occurs in DNA but no
change occurs in the amino acids
1. albinism
2. alcohol
3. alkaptonuria
4. anticodon
5. chromosome
6. codon
7. DNA repair
8. enucleated
9. enzyme
10. familial hypercholesterolemia
11. fragile X syndrome
12. frameshift
13. galactosemia
14. gene
15. haploid
16. Huntington
17. melanin
18. messenger
19. metabolism
20. missense
21. mutagen
22. nonsense
23. nucleotide
24. nucleotide substitution
25. peptide
26. phospho
27. PKU
28. promoter
29. protein
30. radiation
31. ribosome
32. sickle cell anemia
33. silent
34. sugar
35. teratogen
36. thymine dimer
37. transfer
38. transcription
39. translation
40. unfertilized
41. trinucleotide repeat
42. UV light
43. xeroderma pigmentosum

II. True or False
___ 1. The proteins that make up much of an organism’s body come directly
from the diet, rather than being synthesized by the cells.
___ 2. PKU is a metabolic disease that, if untreated, causes severe mental retardation.
___ 3. Most chemical substances that have been tested have been found to be
mutagenic.
___ 4. Most substances that are mutagenic are also carcinogenic.
___ 5. Many mutations occur on their own, spontaneously.
___ 6. Fetal alcohol syndrome babies suffer from genetic damage that can be
passed on to their offspring when they (the FAS babies) attain
reproductive age.
___ 7. Most teratogens cause gene mutations.
___ 8. Transfer RNAs contain triplet anticodons that match up against mRNA codons
at the ribosomes.
___ 9. There are 4 different kinds of amino acids, as compared to 20 different
nucleotides in DNA.
___ 10.The degeneracy of the genetic code means that each mRNA code word
can stand for any of several amino acids.
___ 11. Usually, T is found in RNA and U in DNA.
___ 12. The complex disease sickle cell anemia results from a change in just
one nucleotide pair along a gene.
___ 13. Humans have an entirely different genetic code dictionary than other
organisms.
___ 14. Several different genes usually code for the same enzyme, so the
system has a backup if gene mutation occurs.
___ 15. Afro-Americans have a higher frequency of sickle cell anemia because
heterozygotes are favored in regions of the world where malaria occurs.
___ 16. Tumor suppressor genes encode proteins that suppress cell division.
___ 17. Retinoblastoma occurs mainly in adults.
___18. Protooncogenes are normal cellular genes that encode proteins that initiate or
maintain cell division.

___ 19. Mutations in the BRCA1 and BRCA2 genes account for most cases of breast
cancer.
____20. Breast cancer only occurs in females.
____21. The United States has the lowest age-adjusted Cancer death rate in the world.
___ 22. Most lung cancer in the United States is associated with smoking.
___ 23. Colon cancer is usually preceded by benign tumors known as polyps.
___ 24. For retinoblastoma to develop a cell must lose both copies of the RB tumor
suppressor gene.
___25. Some viruses carry oncogenes as part of their genetic material.
III. Multiple choice, select the single best choice.
1. A typical value for a gene mutation rate (per gene per generation) is (a) 1 in 100 (10 -2 ),
(b) 1 in 1000 (10 -3 ), (c) 1 in 10,000 (10 -4 ), (d) 1 in a million (10 -6 )
2. A mutagen on DNA in skin cells, that doesn't have the energy to mutate DNA in
cells within the body, is (a) alcohol, (b) ionizing radiation, (c) UV light, (d) X-rays
3. A major cause of mental retardation is (a) fragile-X syndrome, (b) familial
hypercholesterolemia, (c) albinism, (d) Huntington’s disease
4. Ultraviolet light damages DNA by causing the formation of (a) double-strand breaks
in the DNA, (b) changes of C to U, (c) ionized OH radicals, (d) thymine dimers in the DNA.
5. Studies have shown that DNA in typical skin cells undergoes vast amounts of damage
from sunlight and from background radiation and chemicals, as well as spontaneously.
The usual result of this damage is (a) death of the cells, (b) large numbers of mutations
that greatly impair cell function, (c) premature aging, (d) no effect on the overall cell
metabolism because humans possess highly effective DNA repair systems.
6. The most common function of a gene is to specify the production of a particular
(a) amino acid, (b) chromosome, (c) polypeptide, (d) sugar
7. A gene consists of (a) a section of DNA beginning with a promoter region and
ending with a terminator regions, (b) a section of DNA beginning with a AUG
codon and ending with a stop codon, (c) a section of protein beginning with the
amino acid methionine and ending with a stop codon, (d) a ribosome reading along
mRNA and bringing in amino acids.
8. Translation consists of the following:
(a) mRNA carries amino acids and is produced from DNA,
(b) tRNAs carry amino acids and read rRNA at ribosomes,
(c) rRNAs carry amino acids and read mRNA codons at ribosomes,

(d) tRNAs carry amino acids and read mRNA codons at ribosomes
9. A metabolic disease that all newborns are screened for in all 50 states.
(a) albinism, (b) Huntington’s, (c) PKU, (d) sickle cell anemia
10. On the template strand of DNA (the strand that serves as the basis for
making rRNA), a mutation occurs that changes a GCC code word to TCC.
The result of the change on the polypeptide is a (a) missense mutation,
(b) nonsense mutation, (c) sense mutation, (d) silent mutation. Use a
genetic code table to work through this question.
11. The most common form of cancer in the United States is cancer of the (a) breast, (b)
prostate, (c) lung, (d) skin.
12. Metastasis refers to the process in which (a) tumors cells die after chemotherapy, (b)
tumor cells move to new sites in the body, (c) benign tumors grow larger, (d) cancer cells
encourage new blood vessels to grow next to them.
13. Sproadic retinoblastoma typically (a) involves cancer in both eyes, (b) occurs in one eye
in adults over 55, (c) occurs in one eye in the latter years of childhood, (d) occurs in both
eyes of college-aged individuals.
14. The most aggressive form of skin cancer is (a) retinoblastoma, (b) basal cell carcinoma,
(c) squamous cell carcinoma, (d) malignant melanoma.
15. Xeroderma pigmentosum is an inherited form of (a) skin cancer, (b) eye cancer, (c)
breast cancer, (d) colon cancer, (e) prostate cancer.
16. The Philadelphia chromosome was generated by (a) an inversion, (b) a reciprocal
translocation, (c) a deletion, (d) a duplication.
IV. Longer answer questions.
1. Suppose you have a DNA molecule whose sequence within a certain gene
begins with A T G G G G C T A …..
T A C C C C G A T ….. template strand for transcription
(a) Write out the mRNA made from this gene
(b) What will be the first three amino acids in the polypeptide chain (use a genetic
code table)?
(c) What are the anticodons that are expected on the tRNAs?

2. What are the following: an amino acid, an anticodon, a codon, an enzyme, a gene, a
nucleotide, a peptide bond, a phospodiester bond, a promoter, a mRNA, a rRNA, a
tRNA, a ribosome, transcription, translation, mutation?
3. In the case of sickle cell anemia, explain what is wrong with the DNA and
with the protein, and what causes the harmful effects on the person.
4. Describe what happens to the DNA, what happens to the polypeptide (protein),
and whether it is serious or not for silent mutations, missense mutations, and
nonsense mutations.
5. In the case of PKU, explain what is wrong with metabolism in cells, what happens to
cause the disease, and what treatment is used.