Download Introduction to Genetics WINTER 2017 EXAM I 1. In one strand of

Introduction to Genetics
WINTER 2017
EXAM I
1.
In one strand of DNA, the nucleotide sequence is 5´AGCT3´. The complementary sequence
in the other strand must be
A) 5´AGCT 3´ B) 5´TCGA 3´ C) 5´CTAG 3´ D) 5´GATC 3´ E) 5´ACGT 3´
2.
The DNA content of an organism contains 50% GC basepairs. On average, how frequently
would you expect to find the sequence 5´AGCT 3´?
A) once every 16 bases
B) once every 32 bases
C) once every 256 bases
D) once every 625 bases
E) once every 4096 bases
3.
The DNA content of an organism contains 80% GC basepairs. On average, how frequently
would you expect to find the sequence 5´ AGCT 3´?
A) once every 16 bases
B) once every 32 bases
C) once every 256 bases
D) once every 625 bases
E) once every 4096 bases
4.
The molecule shown to the right consists of
A)
B)
C)
D)
E)
Ribose attached to the purine base, Adenine
Deoxyribose attached to the purine base, Adenine
Deoxyribose attached to the purine base, Cytosine
Ribose attached to the pyrimidine base, Cytosine
Deoxyribose attached to the purine base, Guanine
5. A rapidly growing archaea has a circular genome that is 4 megabases in size and replicates using two
bidirectional origins of replication. If the cells divide every 20 minutes, what is the minimum speed that
the replication fork must be moving?
A) >200,000 bp/min
B) >100,000 bp/min C) >50,000 bp/min D) >2,000 bp/min E) >1000bp/min
6. The replication machinery allows one error to slip through for each 1X1010 base pairs synthesized.
Given that a human cell contains 6 x 109 base pairs of DNA, on average how many mutations are present
in a 10 cell embryo?
A) <1
B) ~6
C) ~60
D) ~600
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E) >1000
7. The enzyme that unwinds the duplex DNA during replication is called a
A) polymerase
B) telomerase C) primase
D) ligase
E) helicase
8. The enzyme that synthesizes short RNA fragments on the lagging strand during replication is
called
A) polymerase
B) telomerase C) primase
D) ligase
E) helicase
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Questions 9-10 refer to the biochemical pathway below.
In Neurospora, a branched biochemical pathway synthesizes two essential amino acids, D & F
9.
Which compound(s) will accumulate in null mutants lacking enzyme 4?
A) A
10.
B) B
C) C
D) D
E) F
Null mutants lacking enzyme 2 gene will grow on minimal medium supplemented with
which of the following compounds?
A) A
B) B
C) C or D
D) E or F
E) F only
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11.
The labeled parts of the eukaryotic chromosome above could correctly be labeled as:
A)
B)
C)
D)
E)
12.
A= Centromere; B=Euchromatin; C= Telomere; D= Heterochromatin; E= Centromere
A=Telomere; B= Euchromatin; C=Centromere; D= Euchromatin; E= Heterochromatin
A= Heterochromatin; B= Centromere; C= Telomere; D= Euchromatin; E= Heterochromatin
A=Telomere; B= Heterochromatin; C=Centromere; D= Heterochromatin; E= Telomere
A=Telomere; B= Heterochromatin; C= Centromere; D= Heterochromatin; E= Euchromatin
Homologous centromeres are seen to separate to opposite poles of a dividing cell during …
A)
B)
C)
D)
E)
Prophase I of mitotic cell divisions, and Prophase II of meiotic cell divisions.
Prophase I of mitotic cell divisions, and Prophase I of meiotic cell divisions.
Anaphase I of mitotic cell divisions, and Anaphase II of meiotic cell divisions.
Anaphase I of mitotic cell divisions, and Anaphase I of meiotic cell divisions.
Telophase I of mitotic cell divisions, and Telophase II of meiotic cell divisions.
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13.
A process that occurs in meiosis but not mitosis is
A)
B)
C)
D)
E)
chromosome condensation (shortening).
chromatid formation.
cell division.
separation of homologous centromeres to opposite poles.
pairing of homologous chromosomes.
Questions 14-17 refer to the diagram shown below.
A mature mRNA was isolated from mouse cells and hybridized to its corresponding piece of
genomic DNA. The following electron micrograph was obtained:
IV
III
V
II
I
VII
VI
14. The 3’ end of the DNA molecule corresponds to:
A) I
B) IV
C) V
D) VI
E) VII
D) VI
E) VII
15. The 5’ cap would be found on which segment?
A) I
B) IV
C) V
16. The sequence corresponding to an exon on the RNA transcript can be found in which segment?
A) II
B) III
C) IV
D) VI
E) VII
D) V
E) VI
17. Translation would begin from which segment?
A) I
B) II
C) IV
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18. A Sanger sequencing reaction that identifies where Guanines occur in the single strand DNA
template being sequenced would contain: a DNA polymerase, an oligo primer, a single strand
DNA template and…
A) a mixture of all the deoxynucleotide triphosphates, plus dideoxyguanine triphosphate
B) a mixture of all the deoxynucleotide triphosphates, plus dideoxycytosine triphosphate
C) a mixture of all the dideoxynucleotide triphosphates, plus deoxycytosine triphosphate
D) a mixture of all the ribonucleotide triphosphates, plus deoxyguanine triphosphate
E) a mixture of all the ribonucleotide triphosphates, plus deoxycytosine triphosphate
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19. Which pair of pentamer primers could be used to amplify the DNA sequence shown below?
3'-AAAAAGATTACATCGGCATTACCGATTTAAAGCCCTGGGGG-5'
5'-TTTTTCTAATGTAGCCGTAATGGCTAAATTTCGGGACCCCC-3'
A) forward primer 5'-AAAAA-3' and reverse primer 5'-GGGGG-3'
B) forward primer 5'-TTTTT-3' and reverse primer 5'-CCCCC-3'
C) forward primer 5'-AAAAA-3' and reverse primer 5'-CCCCC-3'
D) forward primer 5'-TTTTT-3' and reverse primer 5'-GGGGG-3'
E) forward primer 5'-AAAAA-3' and reverse primer 5'-TTTTT-3'
20. The sequence 5’AAU-3’ if translated would code for what amino acid?
A) Ile B) Leu C) Gln D) Asn E) Met
21. If there are 20 amino acids, how many possible peptides
can be made that are exactly three amino acids long?
A) 60
B) 1,800
C) 8,000
D) 262,144
E) 3,486,784,40
22. If you were to translate a completely randomized DNA
sequence, on average, how often would you expect to
encounter a stop codon?
A) about once every 12.5 codons
B) about once every 21.3 codons
C) about once every 64 codons
D) about once every 128 codons
E) about once every 333.3 codons
23. Translation initiates
A) from a promoter on the DNA
B) at a Ribosome binding site on the RNA
C) from a promoter on the RNA
D) at a Ribosome binding site on the DNA
E) with a DNA polymerase at the origin
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Questions 24 and 25 refer to the following experiment
To differentiate between potential mechanisms for how DNA is duplicated, Meselson-Stahl
set up an experiment to differentially label the strands of the DNA during replication. For this
experimental analysis, a culture of E.coli was grown in media containing heavy isotopes of
nitrogen (15N) for several generations. Cells from this culture were then transferred into media
containing normal nitrogen (14N) and then samples were prepared 1) after one generation in the
normal media, and 2) after two generations of growth in the normal media.
The DNA was then prepared from each sample and its boyant density was determined by
centrifugation CsCl gradients. The results of two control cultures grown in only heavy (15N) media,
and only light (15N) media are shown, along with five potential outcomes, labeled A-E.
Control 1
heavy
media
24.
Control 2
normal
media
A
B
C
D
E
Considering the controls, which samples would support the idea that DNA replicated
semiconservatively?
A) D after one generation, E after two generations
B) C after one generation, D after two generations
C) D after one generation, B after two generations
D) B after one generation, B after two generations
E) D after one generation, A after two generations
25.
Considering the controls, which samples would support the idea that DNA replicated
conservatively?
A) D after one generation, E after two generations
B) C after one generation, D after two generations
C) D after one generation, B after two generations
D) B after one generation, B after two generations
E) D after one generation, A after two generations
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26. Fuzzy (F) is dominant to smooth (f) in peaches. A testcross involving a fuzzy peach produces 50%
fuzzy peaches and 50% smooth peaches. The genotype of the parental fuzzy peach was
A) FF
B) Ff
C) ff
D) FF or Ff
E) Ff or ff
Questions 27 and 28 refer to the following cross:
H U G E are four dominant genes controlling tomato size that are each located on different chromosomes.
A cross is carried out between Plant 1 with genotype- Hh Uu Gg ee and Plant 2 of genotype- hh Uu Gg Ee.
27. What percentage of the progeny are expected to be phenotypically identical to Plant 1?
A) 1/256
B) 1/16
C) 9/64
D) 3/8
E) 81/256
28. What percentage of the progeny are expected to be genotypically identical to Plant 1?
A) 1/256
B) 1/16
C) 9/64
D) 3/8
E) 81/256
29. A cross between two dihybrids would be expected to produce progeny with a phenotypic ratio of
A) 3:1
B) 1:1
C) 9:3:3:1
D) 1:1:1:1
E) all progeny would be phenotypically identical
30.
If genes assort independently, a testcross involving a dihybrid characteristically produces
progeny phenotypes in the ratio
31.
32.
Which of the following genotypes would be considered 'purebreeders' if self fertilized?
A) bbdd
B) BBdd
C) BbDd
D) bbDd
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E) Both A and B
A linear double stranded DNA virus has the following restriction sites in its genome.
EcoRI
BamHI
2.0 kb
1.5kb
0.5 kb
probe hybridizes here
A
B
C
D
E
4kb
3kb
2kb
1kb
0.5kb
The solid bar represents a short PCR fragment that was amplified, radioactively labeled, and used
as a probe for the Southern Blot shown to the right. The probe hybridizes only to the region shown
above on the viral genome. In each lane, the viral DNA was digested with a restriction
endonuclease, and run through an agarose gel. The gel was transferred onto a nylon membrane and
probed with the PCR fragment shown above, and the probe was then visualized after exposing the
southern blot to film.
33. Which lane corresponds to the probe if the viral DNA was digested with EcoRI?
A) A
B) B
C) C
D) D
E) E
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