Genetics Exam Ii

108 Questions  I  By Stephens on February 29, 2012
Genetics Exam II

  

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1.  What observation did Griffith make in his experiment with Streptococcus pneumoniae?
A.
B.
C.
D.
2.  What is a merozygote?
A.
B.
C.
D.
3.  What is transduction?
A.
B.
C.
D.
4.  Which condition produced from an autosomal trisomy results in survival to adulthood?
A.
B.
C.
D.
5.  Why is it important for a retrovirus to carry its own reverse transcriptase protein instead of making it from its reverse transcriptase gene after it infects a cell?
A.
B.
C.
6.  The normally cultivated cotton plant is a tetraploid (52 chromosomes). How many chromosomes did the probable ancestral haploid have?
A.
B.
C.
D.
7.  What is the specific term that describes the loss of a single chromosome (2n - 1)?
A.
B.
C.
D.
8.  Of the following DNA strands in combination with their complementary strands (forming double helices), three undergo a hyperchromic shift with a Tm of about 42*C.  Which one has a Tm of 52*C?
A.
B.
C.
D.
9.  All of the following statements about bacteriophages are true except that
A.
B.
C.
D.
10.  What is the complementary DNA sequence to a 5' ATGCTTGACTG 3'?
A.
B.
C.
D.
11.    Which of the following terms can be used to describe Down syndrome?
A.
B.
C.
D.
12.  The effect of Barr body formation in mammals is that
A.
B.
C.
D.
13.  Which of the following syndromes is not paired with its causative chromosomal aberration?
A.
B.
C.
D.
14.  Chromosomal aberrations may be characterized by all of the following except
A.
B.
C.
D.
15.  The paternal X is always inactivated for dosage compensation in placental mammals.
A.
B.
16.  In a sexually reproducing diploid species, gametes must be
A.
B.
C.
D.
17.  Forty-eight plaques were counted on a plate when 0.1 ml of bacteriophage-infected bacteria from a 10−6 dilution of a 10‑ml culture was plated. The original bacteriophage density was
A.
B.
C.
D.
18.  The sporophyte stage in plants
A.
B.
C.
D.
19.  What conclusion could be drawn if Hershey and Chase had found only 35S in their bacterial cells?
A.
B.
C.
D.
20.  Why would the transmission of Down syndrome resulting from a Robertsonian translocation be unaffected by the age of the mother?
A.
B.
C.
D.
21.  How is sex determined in Drosophila?
A.
B.
C.
D.
22.  Which of the following statements about XYY males is true?
A.
B.
C.
D.
23.  What is the diploid chromosome number of an individual with both Klinefelter syndrome and Down syndrome (three copies of chromosome 21)?
A.
B.
C.
D.
24.  Which of the following statements about double fertilization is true?
A.
B.
C.
D.
25.  Which of the following is an example of infectious heredity?
A.
B.
C.
D.
26.  Which of the following statements about the roundworm C. elegans is false?
A.
B.
C.
D.
27.  A child is born with Down syndrome. Analysis of his karyotype shows two number 21 chromosomes, a single number 18 chromosome, and an additional large chromosome about the size of chromosome 3. Which of the following conclusions can be drawn from the karyotype?
A.
B.
C.
D.
28.  What is one explanation for the difference between the primary sex ratio and the secondary sex ratio in humans?
A.
B.
C.
D.
29.  Which technique can be used to identify the location of genes on a chromosome?
A.
B.
C.
D.
30.  In an Hfr mating with an Fcell, why doesn't the recipient cell always become an Hfr or F+ cell?
A.
B.
C.
D.
31.  A plaque assay detects the number of bacterial auxotrophs on a plate.
A.
B.
32.  What phenotype would be expected in balanced translocation heterozygotes in the absence of position effects?
A.
B.
C.
D.
33.  Hfr bacterial cells exhibit high levels of gene transfer because
A.
B.
C.
D.
34.  If two DNA strands of identical length were analyzed, which of the following statements would be true of their Tm or melting temperature?
A.
B.
C.
D.
35.  Which genetic disease is caused by a trisomy for chromosome 13?
A.
B.
C.
D.
36.  A cross between a tetraploid and a diploid member of the same species will produce offspring that can undergo sexual reproduction.
A.
B.
37.  In the yeast Saccharomyces cerevisiaesuppressive petite mutants exhibit Mendelian inheritance because they result from nuclear mutations.
A.
B.
38.  What results did Avery, McLeod and McCarty obtain in their experiments with virulent bacteria?
A.
B.
C.
D.
39.  What proportions of progeny would be expected from a cross between streptomycin‑sensitive mt+ and streptomycin‑resistant mt strains of the algaChlamydomonas reinhardi?
A.
B.
C.
D.
40.  Which of the following statements about the difference between DNA and RNA is false?
A.
B.
C.
D.
41.  How is a merozygote formed?
A.
B.
C.
D.
42.  Which term specifically refers to the gain of extra chromosome sets from individuals of the same species?
A.
B.
C.
D.
43.  The hypothesis that gene duplication is essential to evolution is supported by the existence of
A.
B.
C.
D.
44.  Which human chromosomes have been observed in an aneuploid condition in fetuses?
A.
B.
C.
D.
45.  Leaf coloration in the four‑o'clock plant, Mirabilis jalapa, was one of the first examples of cytoplasmic inheritance. If ovules from a variegated‑leafed branch are pollinated with pollen from a variegated‑leafed branch, what phenotypes will be observed in the progeny?
A.
B.
C.
D.
46.  Organelle heredity, maternal effect, and infectious heredity are all examples of extranuclear inheritance, which is the transmission of genetic information to offspring through the cytoplasm rather than through the nucleus.
A.
B.
47.  Females with only one X chromosome do not develop; this condition is lethal.
A.
B.
48.  An E. coli nutritional mutant is described as an auxotroph, which requires minimal medium with supplementation of an organic carbon source or inorganic ion for growth.
A.
B.
49.  Which term describes the condition in which cells have a variable mixture of organelles with different genetic origins?
A.
B.
C.
D.
50.  How many chromosomes would be found in an allopolyploid plant if its parents had diploid numbers of 4 and 6 respectively?
A.
B.
C.
D.
51.  Which of the following statements about Barr bodies is true?
A.
B.
C.
D.
52.  Which of the following statements about maternal inheritance is true?
A.
B.
C.
D.
53.  Which of the following phenotypic descriptions does not describe a mitochondrial trait?
A.
B.
C.
D.
54.  Which term best describes an individual with Klinefelter syndrome?
A.
B.
C.
D.
55.  A human with the karyotype 49,XXXYY forms two Barr bodies.
A.
B.
56.  The direction of coiling in the snail Limnaea peregra is determined by the genotype of the maternal parent producing the egg, regardless of the progeny's genotype. Which of the following statements correctly describes this trait?
A.
B.
C.
D.
57.  How can duplications arise?
A.
B.
C.
D.
58.  Which of the following statements best describes the structure of a DNA molecule?
A.
B.
C.
D.
59.  In maize, there are mutant genes that confer male sterility to all of the offspring of the female parent carrying this genotype. This genetic information is not found on any of the chromosomes that make up the maize genome. What is the most likely mode of inheritance for these genes?
A.
B.
C.
D.
60.  Why do some organisms use both sexual and asexual reproduction?
A.
B.
C.
D.
61.  Which of the following statements about the T4 lytic life cycle is false?
A.
B.
C.
D.
62.  Which human genetic disease does not exhibit cytoplasmic maternal inheritance?
A.
B.
C.
D.
63.  How is genetic information transferred during conjugation?
A.
B.
C.
D.
64.  Which of the following statements about the Cot1/2 or half-association value of DNA fragments is true?
A.
B.
C.
D.
65.  What does intergenic mapping involve?
A.
B.
C.
D.
66.  Which of the following statements about nondisjunction is false?
A.
B.
C.
D.
67.  Which of the following statements about dosage compensation is true?
A.
B.
C.
D.
68.  Which of the following human genetic diseases is caused by a segmental deletion (partial monosomy)?
A.
B.
C.
D.
69.  Fragile X syndrome is thought to be caused by the inactivation of a gene spanning the fragile region on the X chromosome due to a large number of trinucleotide repeats just upstream from the coding sequence of the gene.
A.
B.
70.  Which of the following statements about DNA structure is true?
A.
B.
C.
D.
71.  Which of the following statements is not true of Hfr bacteria?
A.
B.
C.
D.
72.  How does the Y chromosome determine maleness in humans?
A.
B.
C.
D.
73.  Which of the following crosses could produce a right‑hand coiled shell heterozygote in the snail Limnaea peregra, if the gene D, which codes for right‑hand coiled shells, is dominant to the gene d, which codes for left‑hand coiled shells?
A.
B.
C.
D.
74.  Which of the following statements does not describe Z-DNA?
A.
B.
C.
D.
75.  Which of the following statements about the endosymbiotic theory is false?
A.
B.
C.
D.
76.  If Avery, MacLeod, and McCarty had determined that the transforming molecule was a protein, what experimental results would not have been observed?
A.
B.
C.
D.
77.  What are pseudoautosomal regions on the sex chromosomes?
A.
B.
C.
D.
78.  Which of the following is true of thymine?
A.
B.
C.
D.
79.  Which of the following statements about individuals with Klinefelter syndrome or Turner syndrome is false?
A.
B.
C.
D.
80.  Which gametes will be produced if nondisjunction occurs during the second meiotic division?
A.
B.
C.
D.
81.  Which of the following crosses could produce a left‑hand coiled shell heterozygote in the snail Limnaea peregra, if the gene D, which codes for right‑hand coiled shells, is dominant to the gene d, which codes for left‑hand coiled shells?
A.
B.
C.
D.
82.  Why is it easier to identify spontaneous mutations in bacteria than in most eukaryotes?
A.
B.
C.
D.
83.  Which human aneuploid condition does not involve a sex chromosome?
A.
B.
C.
D.
84.  What results would be expected from a plaque assay if the dilution factor of the phage‑infected culture were too low?
A.
B.
C.
D.
85.  The fertility factor is a mobile genetic element called a plasmid that contains genes for directing gene transfer between bacterial cells.
A.
B.
86.  Watson and Crick used information from several individuals to construct their model of DNA.  Whose X-ray diffraction studies were critical to their work?
A.
B.
C.
D.
87.  Bacterial cells are always haploid unless
A.
B.
C.
D.
88.  Leaf coloration in the four‑o'clock plant, Mirabilis jalapa, was one of the first examples of cytoplasmic inheritance. If ovules from a white‑leafed branch are pollinated with pollen from a green‑leafed branch, what phenotypes will be observed in the progeny?
A.
B.
C.
D.
89.  Chrysanthemums have a haploid chromosome number of 9. How many chromosomes are found in tetraploid chrysanthemum species?
A.
B.
C.
D.
90.    The incidence of Down syndrome, also known as trisomy 21, increases with increasing maternal age. Which of the following errors most likely produces this condition?
A.
B.
C.
D.
91.  What distinguishes paracentric inversions from pericentric inversions?
A.
B.
C.
D.
92.  Which of the following statements best describes lysogeny?
A.
B.
C.
D.
93.  A human with XXY sex chromosomes is female because she has two X chromosomes.
A.
B.
94.  Which enzyme makes DNA from an RNA template?
A.
B.
C.
D.
95.  Which of the following statements about cotransformation is true?
A.
B.
C.
D.
96.  What limits E. coli growth within a medium culture?
A.
B.
C.
D.
97.  How does recombination in bacteria differ from recombination in eukaryotes?
A.
B.
C.
D.
98.  Which of the following statements about conjugation is true?
A.
B.
C.
D.
99.  When a bacterial cell is transformed, after one round of cell division, only one of the two resulting cells contains new genetic material because
A.
B.
C.
D.
100.  Which of the following elements is not involved in conjugation?
A.
B.
C.
D.
101.  Leber's hereditary optic neuropathy is caused by a mutation in the mitochondrial gene encoding NADH dehydrogenase. The trait exhibits cytoplasmic inheritance and is passed along maternal lines. Often, however, both parents of an affected individual are phenotypically normal, and there is no family history of the disease. What is the most likely explanation for this observation?
A.
B.
C.
D.
102.  If a double-stranded sample of DNA has a base composition of 20% guanine, which of the following statements is true?
A.
B.
C.
D.
103.  RNA differs from DNA in all of the following ways except by
A.
B.
C.
D.
104.  Guanine and adenine are purines found in DNA.
A.
B. <