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Biol 283 Exam 3- Fall 2015
1. Each new DNA strand is initiated by a
Short RNA primer C. Precursor fragment
B. Single-stranded DNA-binding D. Restriction fragment
protein E. Specific DNA primer
2. If guanine makes up 23% of the nucleotides in a sample of DNA, then thymine would make up
what percentage of the bases?
A. 15% D. 30%
B. 22% E. 40%
Oo 27%
3.A chromosome with its centromere in the middle is a
A. Submetacentric D. Holocentric
B. Acrocentric G) Metacentric
C. Telocentric
4. The semisterility of genotypes heterozygous for a reciprocal translocation results from the
lethality due to the chromosomal abnormalities produced by
A. Alternate segregation D. AandB
B. Adjacent-1 segregation @) BandC
C. Adjacent-2 segregation
5. How many Barr bodies would be present in white blood cells of an individual of karyotype 48,
XXYY?
A. 4 Bas C2: @1
6. Following transcription, the RNA has an almost identical sequence (U instead of T) of
which of the following?
A, Regulatory sequences D. The template strand of DNA
B. Termination sequences E. None of these answers
© The coding strand of DNA
7.Alternative splicing allows an organism to P
Carry fewer genes C. Produce fewer gene products
B. Carry more genes D. More than one of the answers
8. Attaches adjacent Okazaki fragments, forming a continuous DNA strand
a DNA ligase D. DNA polymerase |
B. DNA polymerase II E. DNA primase
C. Topoisomerase
9. Which of the following structural motifs promotes dimerization?
A. Zinc finger C. Helix-turn-helix
Leucine zipper D. Helix-loop-helix
10. For the following five sequences, what is the consensus sequence?
5’-GGGAGCG-3’
5’-GAGAGCG-3’
5’-CAGTGCG-3’
5’-GAGAACG-3’
5’-GAGAGCA-3’
A. 5'-GGGAGCG-3’
5’-GAGAGCG-3’
C. 5’-GAGTGCG-3’
D. 5’-GAGAACG-3’
11. Which of the following allows the RNA polymerase II to interact with enhancers and
specific transcription factors?
Mediator D. Sigma factors
TFIIB E. None of the answers are
C. TFIIH correct
12. A functional protein would contain the information coded for within which of the
following regions of DNA?
® Exons D. Promoters
B. Introns E. All of the answers are
C. Enhancers correct
13. Which of the following provides for a higher level of stability in the mRNA?
A. Alternative splicing 3' polyA tailing
B. RNA editing D. Trimming
14. What basal transcription factor is most often directly affected by regulatory/specific
transcription factors?
A. TFIIB Ce TERE
@ TFIID D. TFIIF
15. A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to
histones. What effect would you expect this mutation has on the expression of this
gene?
A. The expression of the gene would be abnormally high.
B. The effect on gene expression is impossible to predict..
C. The gene would encode a different protein instead.
=. The expression of the gene would be abnormally low or absent.
. The promoter of the gene will be constantly available to transcription factors
and RNA polymerase.
16. CpG islands are associated with which of the following?
A. Nucleosome location C. Steroid hormone activity
DNA methylation D. cAMP pathwa
Fill in the blanks with the best word or phrase selected from the list below. Not all words or
phrases will be used; each word or phrase should be used only once.
The o helices and 8 sheets are examples of protein 36 E
structure. A protein such as hemoglobin, which is composed of more than
one protein 37D , has 38 ® structure. A
protein’s amino acid sequence is known as its 39 :
structure. Aprotein__ 40 x 2 is a compact and stable folded
region of a polypeptide that can be conserved between different members of
a protein 41 © . The three-dimensional conformation of a protein
is its 42 K structure. Post-translation, 43 E
further modulates the structure and function of proteins.
A. tertiary E. covalent modification C. primary
B. domain A. sheet D. subunit
C. family B. quaternary E. secondary
D. helix
Use the letters in the diagram of a replication fork in the figure.
44,
45.
46.
47.
48.
49.
50.
DNA polymerase 8
single-strand binding
protein |}
Okazaki fragment O
primase®
sliding clamp (\
RNA primer £
DNA helicase C, A
1
51-56: The figure shows a replication bubble. Label it as instructed below.
51. On the figure, indicate where the origin of replication was located (use an O).
52. Label the leading-strand template and the lagging-strand template of the right-hand
fork [R] as X and Y, respectively.
53. Indicate by arrows the direction in which the newly made DNA strands (indicated by
dark lines inside of the bubble) were synthesized.
54. Number the Okazaki fragments on each strand 1, 2, and 3 in the order in which they
were synthesized.
55. Indicate where the most recent DNA synthesis has occurred (use S).
56. Indicate the direction of movement of the replication forks with arrows.
57. Which of the following terms should NOT be used to describe a human with three
copies of chromosome 12? (choose all that apply).
Polyploid Euploid
Triploid e. 2n+1
©, Aneuploid = f. Trisomy 12
58. A diploid fruit fly has eight total chromosomes (4 pairs). How many total chromosomes
would be found in the following flies? >
a. \G Tetraploid d. 3 3n
b. 4 Trisomy 2 e. |] 4n+1
7. Monosomy 3
59. Awoman who is heterozygous Bb, has brown eyes. B (brown) is a dominant allele, and
b (blue) is recessive. In one of her eyes however there is a patch of blue color. Give
three different explanations for how this might have occurred. (three points)
mitotic. nrondis sSyarclion > ~ ae WNeles couldh eds up Same cel|
Chromosome Camy a ele WoS lost
B allele could be~Gele ea mnskerbod|
epiaene Lic siknenG & ~G&” allele — wl ly lafen "ke uaa?
( nists mod iran
- 45 yoru mechen wrocalrad ANA
iseaphyd ex prissich KB" allele elas mena)
I
V4
f
60. Explain why inversions and reciprocal translocations do not usually cause a phenotypic
effect. In a few cases, however they do. Explain how and be specific. (two points)
- No net ain [loss oy wernatic - balance ,)
a Het eho s charge gene expassion pallerns (polerfall
car Wea
61. A zookeeper has collected a = and female lizard that look like they belong to the
same species. They mate with each other and produce phenotypically normal offspring.
However, the offspring are sterile. Suggest one explanation for their sterility (there are
a few options). (two ae
Sone Amer could \oid wu] the other Letriploid , OSs arn
walk \yo. trip vid Pat a skrile, pr s
- Inversion aa also explarh
62. Describe some of the advantages of polyploidy plants. What are the primary
consequences of having an odd number of chromosome sets? Are the consequences of
having an odd number of chromosomes beneficial or detrimental? Explain. (two points)
-larger, mort robust impleid plants can also bloom continuously
ee number = sterile fi a 7 |
~sterility can be seen as pos: she or negadve baseck on especre.
jo ccedls = exe ple pleasant fo'eat, buat mort: coo| aver seeds 7, large
63. Roughly, how do the half life of DNA and RNA compare? What is the significance of these hall cope S
lives, and why would it be detrimental for the molecule with the shorter half life to be more
eae (r5al | \ years) h= very Short C wnneeles por
~We need tthe “DUA ee es be we fable , hove rer~ femp
conta A oe exprssien — het | RVA he wv galarly deg pos l
64. RNA is single stranded. What are the impli
function of RNA in cells? Be specific. (three p
Smt RHA is seme shereled. iL is able to SL ante
Complex Lnee- dimenhonal shapes capable oy cll oun
atts D ribose eyes
65. What chemical group is required for DNA polymerase to add new nucleotides toa
growing DNA strand? Is this on the 3’ or 5’ end of the DNA? (two points)
Fre 3! OH Chydraeyl )
ations of this on the final ld and
66. A DNA strand has the following sequence:
5'- GATCCCGATCCGATCCTGGGCTTAACTAGGAATTCCAAAGT-3’
In which direction would DNA polymerase slide along this strand Ae one)? (two
points)
from left to right or from right