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OE COMPILATIONS
(Opoku Emmanuel)
KWAME NKRUMAH UNIVERSITY OF SCIENCE & TECHNOLOGY
COLLEGE OF SCIENCE –DEPT OF THEORETICAL & APPLIED BIOLOGY
RESIT Examinations, 2012/2013
1st Year Biology, Biochemistry, Human Biology, Dentistry & Veterinary
Medicine
Biol. 153
SEPTEMBER 2013
NOTE:
Basic & Medical Genetics 1
THREE HOURS
YOU ARE FREE TO TAKE THE QUESTION PAPER AWAY FROM THE EXAMINATION HALL .
Attempt As many Questions as your planned time will allow you, in BOTH
SECTIONS 1 and 2. You will NOT be prompted to move between sections.
Sections 1 & 2 must be answered using the scannables. Answer each section
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on the scannable you have appropriately labelled in pencil as SECTIONS 1
AND 2 at the bottom.
CAREFULLY WRITE AND SHADE IN YOUR INDEX NUMBER AND
COURSE CODE
P.S. Please if you perceive a mistake in a question or you think a particular question is not understood,
QUICKLY MOVE ON TO THE NEXT. Do not disrupt the rhythm of the class by asking the invigilator for
corrections. Adequate provisions are made for such anomalies in the final evaluation. DO NOT BOTHER
THE INVIGILATOR WITH ANY QUESTIONS.
ALL QUESTIONS CARRY EQUAL MARKS so work speedily through the questions.
SECTION I
1. .Which of the following represent the possible genotypes resulting from a cross between
two individuals that are heterozygous for black hair (Bb)?
a) BB and Bb
b) BB, Bb and bb
c) BB only
d) Bb only
e) bb only
2. Which of the following represent the possible genotypes resulting from a cross between
an individual homozygous for black hair (BB) and an individual homozygous for blonde
hair (bb)?
a) BB and Bb
b) BB, Bb and bb
c) BB only
d) Bb only
e) bb only
3. Heterozygosity can be determined by:
a) the appearance of the individual.
b) the appearance of the parents.
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c)
d)
e)
4.
a)
b)
c)
d)
e)
5.
a)
b)
c)
d)
e)
6.
a)
b)
c)
d)
e)
7.
a)
b)
c)
d)
e)
8.
a)
b)
c)
d)
e)
9.
a)
a test cross of the unknown individual with a homozygous individual.
both a and b
both band c
What is the probability that two lizards that are heterozygous for stripes on their tails
(Ss) will produce an offspring that is homozygous for no stripes (ss)?
They will always produce offspring that are homozygous for no stripes.
The probability is 1/2 that they will produce offspring homozygous for no stripes.
The probability is 1/4 that they will produce offspring homozygous for no stripes.
The probability is 1/8 that they will produce offspring homozygous for no stripes.
They will never produce offspring homozygous for no stripes.
For which of the following can the laws of probability be applied?
To predict the chances of winning the lottery.
To predict the chances of producing a female child.
To predict the chances of producing a male child.
All of the above.
None of the above.
If brown eyes are dominant over blue eyes and two brown eyed individuals have a child
with blue eyes then that means:
both parents are homozygous for brown eyes.
both parents are heterozygous for brown eyes.
there is a 3/4 chance that their second child will have brown eyes.
there is a 50/50 chance that their second child will have blue eyes.
none of the above are true.
Two Martians fall in love and get married. One Martian is homozygous for red eyes (RR)
while the other is heterozygous for red eyes (Rr). The recessive eye color is purple. What
are the chances that they will have a child with purple eyes?
1/1
½
¼
¾
0
What are the chances that the alien couple will have a child with red eyes?
1/1
½
¼
¾
0
What are the chances that the alien couple will have a child that is heterozygous for eye
color?
1/1
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b) ½
c) ¼
d) ¾
e) 0
10. What are the chances that the alien couple will have a child that is homozygous for red
eyes?
a) 1/1
b) ½
c) ¼
d) ¾
e) 0
11. The probability that two genes will be separated by crossing over is related to:
a) the trait that they control.
b) the distance between the gene and the centromere.
c) the distance between them on the chromosome.
d) Both a and b
e) Both band c
12. Genes that tend to be inherited together are said to be:
a) associated.
b) related.
c) similar.
d) linked.
e) alleles.
13. Human females have two X chromosomes, a condition which is referred to as:
a) a sex-linked trait.
b) dominant chromosome sex determination.
c) homogametic.
d) heterogametic.
e) none of the above.
14. Why are slightly more male children born than are females?
a) X-bearing sperm are less likely to survive spermatogenesis.
b) Y-bearing sperm must have some competitive advantage over X-bearing sperm.
c) More Y-bearing sperm are produced.
d) All of the above are true.
e) None of the above are true.
15. When pink-flowered plants were crossed they produced red-flowered, pink-flowered, and
white-flowered plants in a ratio of 1:2:1. This is an example of:
a) variegation.
b) hybrid vigor.
c) incomplete dominance.
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d) epistasis.
e) a polygenic trait.
16. Breeding a yellow dog to a brown dog produced mixed color puppies (with both yellow
and brown hairs). This is an example of :
a) variegation.
b) codominance
c) incomplete dominance.
d) epistasis.
e) a polygenic trait.
17. _____ refers to a situation in which several pairs of alleles interact to affect a single
trait.
a) Variegation
b) Codominance
c) Incomplete dominance
d) Epistasis
e) None of the above
18. The mating of totally unrelated strains is called _____ and often results in improvement
that is called ______
a) inbreeding, epistasis
b) outbreeding, hybrid vigor
c) outbreeding, hybrid breakdown
d) inbreeding, hybrid vigor
e) none of the above
19. The antiparallel nature of DNA is best explained by which of the following?
a) The two strands run in opposite directions; each has an exposed 5' phosphate on one
end and exposed 3' hydroxyl group on the other.
b) The two strands run in the same direction, making it a simple matter to copy an identical
but antiparallel strand of RNA.
c) The bases are antiparallel to the long axis of the molecule.
d) Both a and c are true.
e) None of the above are true.
20. ____ hydrogen bonds can form between guanine and cytosine while hydrogen bonds form
between adenine and thymine.
a) 1; 2
b) 2; 3
c) 3; 4
d) 4; 3
e) 3; 2
21. Erwin Chargaff and coworkers determined that:
a) The ratio of purines to pyrimidines is not far from one.
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b) The ratio of adenine to thymine is not far from one.
c) The ratio of guanine to cytosine is not far from one.
d) All of the above are true.
e) None of the above.
22. Why don't adenine and cytosine hydrogen bond with each other?
a) They are antiparallel and are not attracted to each other.
b) The pairing of adenine and cytosine does not lead to favorable hydrogen bonding
c) Adenine is a purine and cytosine is a pyrimidine.
d) Both a and b are true.
e) Both band c are true.
23. What evolutionary advantage is provided by meiosis?
a) Genetic diversity.
b) Sexual dimorphism.
c) Diploidy.
d) Polyploidy.
e) None of the above.
24.
A woman is diagnosed to have the genetic disease known as Huntington's disorder. It is a
rare defect caused by an autosomal dominant allele. The chance for anyone of her children to
inherit the disease is
a) dependent on the sex of the child.
b) 1/3
c) ½
d) ¾
25. Karyotyping is useful for determining:
a) the number of chromosomes in an individual.
b) if recessive traits are present.
c) if a specific gene is missing from a chromosome.
d) if gene mutations have occurred.
e) Both c and d are true.
26. The correct number of chromosomes is maintained in higher species by:
a) A process by which one-half of the chromosomes in gametes are removed.
b) Chromosome reduction in the newly formed zygote.
c) A sexual cycle called meiosis which reduces the chromosome number by half.
d) Both a and b are true.
e) Both band c are true.
27. How do plant cells differ from animal cells during mitosis?
a) Plant cells lack spindle fibers.
b) Animal cells have a pair of centrioles in the middle of each microtubule-organizing
center.
c) Plant cells lack centrioles in their microtubule-organizing centers.
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d) Both a and b are true.
e) Both band c are true.
28. What role do centrioles play in spindle formation in animal cells?
a) They probably do not play a role in spindle formation in animal cells.
b) They organize the correct arrangement of spindle fibers to ensure the correct distribution
of chromosomes.
c) Centrioles initiate activity in the aster.
d) Centrioles provide the ATP to fuel spindle formation.
e) None of the above are true.
29. During mitosis nucleoli disappear during ___ and again become apparent during.
a) metaphase, anaphase
b) prophase, anaphase
c) prophase, telophase
d) interphase, telophase
e) anaphase, telophase
30. The kinetochore serves which of the following functions?
a) The kinetochore anchors spindle fibers to centrioles.
b) The kinetochores are the site of rRNA synthesis.
c) Kinetochores regulate the length of the cell cycle.
d) Kinetochores attach to the centromere of chromosomes during mitosis.
e) Both band c are true.
31. In an autosomal dominant disorder such as Huntington's, two carrier parents have the
probability of passing the gene on to _____ percent of their children.
a) 50
b) 0
c) 100
d) 25
e) 75
32. How does the replication of cellular organelles relate to the cell cycle?
a) Organelles replicate at roughly the same time as do the chromosomes.
b) Organelles replicate during interphase and are apportioned more or less between
the daughter cells.
c) Organelles contain their own chromosomes that undergo a mitosis of their own while the
cell is dividing.
d) None of the above are true.
e) Both a and c are true.
33. An organism with a diploid number of 36 chromosomes will have ____ chromosome in
their gametes and _____ chromosomes in their somatic cells.
a) 18, 18
b) 18, 36
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c) 36, 18
d) 36, 36
e) 36, 72
34. What role has polyploidy played in plant evolution?
a) Polyploidy has allowed plants to omit the process of chromosome reduction during
meiosis.
b) Polyploidy plants are often larger and more hardy than are diploid plants.
c) Polyploidy allows crossing to occur between unrelated species of plants.
d) None of the above are true.
e) Both a and c are true.
35. Constant chromosome number is ensured in sexually reproducing species by:
a) Mitosis
b) Meiosis
c) Fertilization
d) Both a and b are true.
e) Both band c are true.
36. During S phase of the cell cycle, which of the following take place?
a) Organelles are replicated.
b) DNA is replicated.
c) Chromosomal proteins are replicated.
d) A cell plate is synthesized.
e) Both band c are true.
37. Which of the following are produced by meiosis?
a) polar bodies
b) eggs
c) sperm
d) fungal spores
e) All of the above.
38. The complex formed between a maternal homologue and a paternal homologue is called
a (n):
a) bivalent
b) tetrad
c) synaptonemal complex
d) sister chromatid
e) Either a or b
39. Why is prophase I longer during the formation of egg cells in some species?
a) Prophase I involves chromosomal replication and therefore takes longer than prophase II.
b) Prophase I involves chromosomal reduction and therefore takes longer than prophase II.
c) The cell grows and synthesizes nutrients required by the future embryo during
prophase I.
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d) None of the above are true.
e) Both a and c are true.
40. When does crossing over occur?
a) during interphase
b) during prophase I
c) during metaphase I
d) during prophase II
e) during metaphase II
41. During prophase I, each chiasmata represents:
a) the site at which homologous chromosomes are united
b) the site at which maternal and paternal homologues are united
c) a newly formed haploid gamete
d) a site of crossing over
e) None of the above
42. During which of the following stages of meiosis do the chromatids separate?
a) metaphase I
b) anaphase I
c) metaphase II
d) anaphase II
e) telophase II
43. _____ egg(s) are formed by oogenesis and ____ sperm (s) are formed by
spermatogenesis.
a) 4, 4
b) 1, 1
c) 4, 1
d) 1, 4
e) 2, 2
44. Heredity is based on which of the following?
a) A complex mechanism used to precisely copy DNA.
b) A mechanism by which genetic information is distributed to offspring.
c) A mechanism by which only the most desirable traits are passed to offspring.
d) All of the above are true.
e) Only a and b are true.
45. Which of the following phenomena are exceptions to Mendel's principles?
a) linkage
b) sex linkage
c) polygenic inheritance
d) all of the above
e) none of the above
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46. During prophase I of meiosis, homologous chromosomes lie side by side. This
phenomenon is known as:
a) homologue pairing
b) synapsis
c) tetrad formation
d) paternal pairing
e) None of the above.
47. Which of the following is/are required to study inheritance?
a) spring pollinating plants
b) genetic variation
c) true breeding lines
d) both a and b are true
e) both band c are true
48. Which of the following represent the possible genotypes resulting from a cross between
an individual homozygous for black hair (BB) and an individual heterozygous for black
hair (Bb)?
a) BB and Bb
b) BB, Bb and bb
c) BB only
d) Bb only
e) bb only
49. Why is a DNA molecule able to store large amounts of information?
a) It contains a large number of different nucleotides.
b) Its nucleotides can be arranged in a large number of possible sequences.
c) It is capable of assuming a wide variety of shapes.
d) Both a and b are true.
e) Both a and c are true.
50. How is a single strand of DNA able to serve as a template for another strand?
a) The complementary pairing of nucleotides means that nucleotides would pair with those
of the original strand to form a new strand.
b) Hydrogen bonds holding the two strands together would be easy to break allowing a
single strand to serve as a template.
c) A single strand of DNA is not able to serve as a template.
d) One strand of DNA directs the synthesis of a new strand on its partner.
e) Both a and b are true.
51. Which of the following is the best definition of semi-conservative replication?
a) The translation of a DNA molecule into a complementary strand of RNA.
b) The fact that a DNA molecule consists of one parental strand and one new strand.
c) The fact that the number of DNA molecules is doubled with every other replication.
d) Both a and b are true.
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e) None of the above are true.
52. Why does DNA synthesis only proceed in the 5'→ 3' direction?
a) Because DNA polymerases can only add nucleotides to the 3' end of a polynucleotide
strand.
b) Because the 3' end of the polynucleotide molecule is more electronegative than the 5' end.
c) Because that is the direction in which the two strands of DNA unzip.
d) Because that is the only direction that polymerases can be oriented.
e) None of the above are true.
53. The DNA strand that is replicated smoothly and continuously is called the:
a) primary strand.
b) first strand.
c) leading strand.
d) alpha strand.
e) None of the above.
54. A replication fork:
a) is only seen in prokaryotic chromosomes.
b) is only seen in eukaryotic chromosomes.
c) is a Y-shaped structure where both DNA strands are replicated simultaneously
d) Both a and b are true.
e) Both band c are true.
55. Each Okazaki strand is initiated by:
a) the same RNA primer that began synthesizing on the leading strand.
b) RNA polymerase.
c) DNA polymerase
d) a separate RNA primer.
e) None of the above.
56. Okazaki fragments are joined together by:
a) RNA polymerase
b) DNA ligase
c) DNA polymerase
d) RNA ligase
e) None of the above.
57. Nucleosomes are best described as:
a) eukaryotic DNA associated with histone proteins.
b) prokaryotic DNA associated with nonhistone proteins.
c) eukaryotic DNA associated with nonhistone proteins.
d) prokaryotic DNA associated with histone proteins.
e) None of the above.
58. Densely staining regions of highly compacted chromatin in the chromosome are called:
a) heterochromatin.
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b) homochromatin.
c) histone dependent chromatin.
d) primary chromatin.
e) None of the above.
59. Heterochromatin:
a) is darkly staining chromatin that is generally not transcribed.
b) is the portion of chromatin that is transcribed into a functional gene product.
c) contains the sequences that are required to regulate translation.
d) contains the sequences that are required to regulate transcription.
e) None of the above are true.
60. Which of the following types of processing does eukaryotic mRNA undergo before it is
functional?
a) Splicing
b) Capping
c) Polyadenylation
d) All of the above
e) None of the above.
61. Proteolytic processing of eukaryotic proteins involves:
a) removal of a portion of the polypeptide chain from an inactive precursor form of the
protein.
b) the addition of one or functional groups to a precursor protein.
c) the removal of one or more functional groups from a precursor protein.
d) Both a and b are true.
e) Both band c are true.
62. Chemical modification of eukaryotic proteins involves:
a) removal of a portion of the polypeptide chain from an inactive precursor form of the
protein.
b) the addition of one or more functional groups from a precursor protein.
c) the removal of one or more functional groups from a precursor protein.
d) Both a and b are true.
e) Both band c are true.
63. Recombinant DNA technology has led to major breakthroughs in:
a) Genetics
b) Evolution
c) Cell biology
d) All of the above
e) Only a and c are true.
64. What have bacteria contributed that is necessary for producing recombinant DNA?
a) Special RNA polymerases.
b) Ligases that seal prokaryotic and eukaryotic DNA segments.
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c) Restriction enzymes.
d) A system in which DNA can replicate without the presence of a nuclear envelope.
e) None of the above.
65. What purpose do restriction enzymes play in bacterial cells?
a) Restriction enzymes prevent the overproduction of mRNA in the bacterial cell.
b) Restriction enzymes attack bacteriophage DNA when it enters the cell.
c) Restriction enzymes promote bonding of the promoter to the mRNA molecule.
d) Restriction enzymes limit the rate of bacterial replication.
e) None of the above.
66. Chromatin is made up of:
a) DNA
b) RNA
c) protein
d) All of the above
e) Only a and c Human genetic traits are influenced by:
a) the genes that were inherited from the organism's parents.
b) the environment.
c) those genes in the genome that are actually expressed.
d) All of the above are true.
e) None of the above are true.
67. The science of cytogenetics is:
a) the study of chromosomes.
b) applicable to haploid organisms only.
c) involves analysis of pedigrees.
d) Both a and b are true.
e) None of the above are true.
68. Which of the following provides evidence that one of the X chromosomes is inactivated in
mammals?
a) the fact that the DNA of one of the X chromosomes in female mammals is not packaged
into nucleosomes.
b) the fact that one of the X chromosomes in female mammals becomes
heterochromatic.
c) the fact that only one of the X chromosomes in female mammals has the required
promoters required for translation.
d) Both a and c are true.
e) Both band c are true.
69. Why is Drosophila so useful in genetics experiments?
a) Because they have just a few chromosomes it is possible to relate genetic data with the
number of chromosomes.
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b) Because their chromosomes are so large it is possible to relate genetic data to
chromosome structure.
c) Because they have such short life spans it is possible to track genetic traits over many
generations.
d) Because these studies have led to the development of techniques, such as karyotyping,
that are useful in human genetic studies.
e) All of the above are true.
70. Polyploidy:
a) may be the result of more than one sperm fertilizing an egg.
b) is lethal in humans.
c) may be the result of the failure of chromosomes to separate during meiosis.
d) Both a and b are true.
e) All of the above are true.
71. The DNA strand that is replicated in a discontinuous manner is called the ____ strand
and is synthesized in short pieces called _____
a) primary; leaders
b) lagging; fragments
c) lagging; Okazaki fragments
d) Okazaki; laggers
e) None of the above.
72. Aneuploidies are:
a) a phenomenon that only occurs in some species of plants.
b) a condition in which an extra chromosome is present or one is absent.
c) a defect that is almost always fatal in humans.
d) uncommon in humans.
e) almost always mutations with a beneficial effect on the individual.
73. Turner syndrome is an example of a condition.
a) monosomic
b) disomic
c) trisomic
d) Both a and b
e) None of the above
74. Down syndrome is an example of a _ condition.
a) monosomic
b) disomic
c) trisomic
d) Both a and b
e) None of the above
75. The principle of dominance states that:
a) the dominant trait shows up at least 50% of the time in the first generation.
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b) the F1 generation of a hybrid cross always exhibit dominant traits.
c) one gene can mask the expression of another in a hybrid.
d) all of the above are true.
e) none of the above are true.
76. Every inherited feature of an organism is controlled by:
a) two genes.
b) two chromosomes.
c) polygenic inheritance
d) hybrid vigor
e) none of the above
77. The principle of segregation states that:
a) the separation of a species into two populations is the main mechanism of speciation.
b) the genes of a pair separate before gametes are formed.
c) dominant genes always remain paired during gamete formation while recessive genes
separate.
d) both a and b are true.
e) both a and c are true.
78. The location of a particular gene on a chromosome is called a(n):
a) allele.
b) locus.
c) trait.
d) map point.
e) none of the above
79. Nondisjunction during mitosis leads to:
a) an individual with a clone of abnormal cells.
b) an individual with all abnormal cells.
c) death of the daughter cells.
d) nonviable sperm.
e) None of the above.
80. _____ are genes that govern the same feature, such as eye color, and occupy
corresponding positions on homologous chromosomes.
a) Alleles
b) Loci
c) Homozygotes
d) Coupled traits
e) None of the above
81. The mating of two individuals that carry different alleles for the same trait is called:
a) a monotrait cross.
b) a monohybrid cross.
c) a ditrait cross.
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d) a dihybrid cross.
e) none of the above.
82. Persons with a 14/21 chromosome have:
a) only one normal chromosome 14.
b) 14/21 of a normal human genome.
c) chromosome 21 translocated onto a chromosome 14.
d) only one normal chromosome 21.
e) a, c, and d are true.
83. Nuclear sexing involves:
a) examination of the nucleus by electron microscopy.
b) examination of the nucleus for the presence of the Barr body.
c) altering the sex of a cell after fertilization.
d) influencing which of the X chromosomes becomes the Barr body.
e) None of the above.
84. Why are sex chromosome abnormalities relatively well tolerated?
a) Because of the phenomenon of dosage compensation.
b) Because these abnormalities are usually acquired in an adult animal.
c) Because these abnormalities usually involve minor metabolic errors.
d) All of the above are true.
e) None of the above are true.
85. Which of the following abnormalities is most likely to be lethal?
a) X chromosome monosomy
b) Autosomal monosomy
c) X chromosome trisomy
d) Autosomal trisomy
e) None of the above
86. Persons having a XXY karyotype, are nearly normal males, but produce few or no sperm.
They have ___ syndrome.
a) Turner
b) Klinefelter
c) Down (trisomy form)
d) Phenylketonuria
e) Down (translocation form)
87. Persons having a XO karyotype are sterile. They have ___ syndrome.
a) Turner
b) Klinefelter
c) Down (trisomy form)
d) Phenylketonuria
e) Down (translocation form)
88. Nearly half of the pregnancies that end in miscarriage have:
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a) trisomy of chromosome 21.
b) homozygosity for a recessive lethal allele.
c) major chromosomal abnormalities.
d) Klinefelter syndrome.
e) None of the above
89. Most inborn errors of metabolism:
a) are inherited as autosomal recessives.
b) are inherited as X chromosome recessives.
c) are primarily due to environmental factors.
d) Both a and c are true.
e) None of the above are true.
90. How do prokaryotic and eukaryotic chromosomes differ?
a) Prokaryotic organisms have a single, circular DNA molecule.
b) Prokaryotic organisms have a single, circular DNA molecule and one or more smaller,
linear chromosomes.
c) Eukaryotic organisms have more than one linear chromosome.
d) Both a and b are true.
e) Both a and c are true.
91. Why is color-blindness more common in males than in females?
a) Because females would have to receive two copies of the recessive color blindness gene
to actually express the trait.
b) Because a male only need receive the recessive gene from his mother to be color-blind.
c) Because color-blindness is an X-linked trait.
d) All of the above.
e) None of the above.
92. Why do male fruit flies increase the metabolism of their X chromosome?
a) To produce the hormones required to maintain their male traits.
b) To compensate for only having one copy of the genes located on the X chromosome.
c) To prevent recessive genes from being expressed.
d) Both a and b are true.
e) Both band c are true.
93. Calico cats are never male because:
a) recessive genes are not usually expressed on their only X chromosome.
b) they would be sterile and therefore unable to pass on the trait.
c) two different alleles for calico coat color to occur require two X chromosomes.
d) all of the above are true.
e) none of the above are true.
94. Which of the following best defines the word "gene"?
a) A gene contains the information to control one trait such as eye color.
b) A gene is a part of a DNA molecule that translates into an RNA molecule.
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c) A gene is the basic structural component of the chromosome.
d) A gene is species specific and determines the sex of an individual.
e) None of the above are true.
95. Palindromic sequences:
a) allow scientists to determine the sequences of nucleic acids in a segment of DNA.
b) consist of two DNA strands that read the same but in opposite directions.
c) are two strands of DNA that read the same and are both oriented in the same direction.
d) Both a and b are true.
e) Both a and c are true.
96. How can two species have the same number of chromosomes yet be very different in
appearance?
a) Although two species may have the same number of chromosomes, they have differing
structures and sizes.
b) The environment in which the zygote develops will create differences in the two species.
c) It is the information specified by genes on the chromosomes that makes each species
unique, not the number of chromosomes.
d) Both a and b are true.
e) Both band c are true.
97. Chromosomes are duplicated during ___
a) G1 phase.
b) G2 phase.
c) S phase
d) metaphase
e) prophase
98. Which of the following marks the beginning of G2 phase?
a) Formation of the spindle apparatus.
b) Formation of a cleavage furrow.
c) Increased uptake of molecular oxygen.
d) Increased protein synthesis.
e) The beginning of mitosis.
99. Eukaryotic chromosomes (of most species) become visible with the microscope during
_____
a) anaphase
b) interphase
c) metaphase
d) prophase
e) telophase
100.
How are restriction enzymes used in recombinant DNA technology?
a) Restriction enzymes are used to cut DNA into shorter fragments.
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b) Restriction enzymes allow scientists to limit the quantities of mRNA that the cell
produces.
c) Restriction enzymes are used to join two DNA sequences.
d) Both a and c are true.
e) Both band c are true.
101.
Why is pattern baldness more common in men than in women?
a) The gene may be recessive in females due to the presence of female sex hormones.
b) Because of the effect of genes on the Y chromosome.
c) Because females would need to be homozygous for the trait to express pattern baldness.
d) Both a and b are true.
e) Both a and c are true.
102.
"Sticky ends" are:
a) the single-stranded end of a DNA segment that can pair with the complementary singlestranded ends of other DNA molecules that were cut with the same restriction enzyme.
b) a problem in recombinant DNA technology because they can lead to the formation of
loops of single stranded DNA.
c) used to insert eukaryotic DNA into a prokaryotic chromosome.
d) Both a and b are true.
e) Both a and c are true.
103.
Which of the following can be used as DNA vectors?
a) Bacteriophages
b) Plasmids
c) E. co1i cells
d) Both a and b
e) Both a and c
104.
Why might a scientist choose a bacteriophage rather than a plasmid to use as a
DNA vector?
a) Bacteriophages are easy to cultivate.
b) Bacteriophages can carry larger DNA molecules than can plasmids.
c) Bacteriophages are more stable as DNA vectors than are plasmids.
d) Bacteriophages transmit additional characteristics to E. coli that help it adapt to the newly
introduced DNA.
e) None of the above are true.
105.
How may recombinant DNA molecules be introduced to mammalian cells?
a) By adding plasmids to the mammalian cells.
b) By using engineered viruses as vectors.
c) By splicing the needed genes into a mammalian chromosome using restriction enzymes.
d) Both a and b are true.
e) Both a and c are true.
106.
Genetic probes are:
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a) radioactively labeled segments of RNA or single-stranded DNA used to identify the
DNA of interest.
b) Fluorescently labeled segments of mRNA that code for the protein product of interest.
c) fluorescently labeled segments of single-stranded DNA used to pair with the DNA of
interest.
d) Both a and c are true.
e) None of the above are true.
107.
Hybridization involves:
a) complementary base-pairing of the DNA probe with the DNA segment of interest.
b) base-pairing of labeled RNA with the DNA of interest.
c) base-pairing of mRNA with tRNA.
d) Both a and b are true.
e) None of the above are true.
108.
A genomic library consists of fragments of
a) all the DNA that occurs in one species.
b) all the DNA contained in one chromosome.
c) all the DNA that would be found in a typical cells of a particular organism.
d) all the DNA in a recombinant gene.
e) Both a and c are true.
109.
To avoid the introduction of introns into the vector ___ is made using the enzyme
__
a) sDNA, RNA polymerase
b) cDNA, DNA ligase
c) cDNA, reverse transcriptase
d) sDNA, reverse transcriptase
e) cDNA, DNA polymerase
110.
How is reverse transcriptase used to clone genes?
a) Reverse transcriptase is used to make a cDNA copy of an mRNA strand, thereby
eliminating introns.
b) Reverse transcriptase is used to make a cloned DNA copy of a plasmid DNA molecule.
c) Reverse transcriptase is necessary to read the information contained on the cDNA
molecule.
d) Both a and b are true.
e) Both b and c are true.
111.
Why are the results of DNA fingerprinting sometimes ruled inadmissible in court
cases?
a) The DNA samples used in the technique are very small and may have been
degraded.
b) Even when great care is taken, the results obtained from this technique are highly
variable, making it difficult to prove guilt or innocence beyond a reasonable doubt.
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c) DNA fingerprinting takes too long to perform to make it a truly useful technique.
d) Both a and b are true.
e) Both a and c are true.
112.
How is insulin produced by genetically engineered E. coli cells superior to insulin
obtained from animal sources?
a) Animal insulin has a shorter life span than insulin produced using recombinant DNA
techniques.
b) Recombinantly produced insulin contains human rather than animal sequences,
thus reducing the chances of an allergic response in the recipient.
c) Animal insulin is more difficult to purify than is recombinantly produced insulin.
d) All of the above are true.
e) None of the above are true.
113.
Which of the following have contributed to our understanding of human genetics?
a) Population studies
b) Pedigree analysis
c) Genetic engineering technology
d) All of the above
e) a and b only
Why are most persons with phenlyketonuria to discontinue a low phenylalanine diet by
adolescence?
a) The defect causing the condition has usually been repaired by that time.
b) The person is usually not sensitive to phenylketones by that time.
c) The person can produce sufficient quantities of the enzymes needed to convert
phenylketones into tyrosine by then.
d) All of the above are true.
e) None of the above are true.
114.
The effects of maternal PKU:
a) can often be prevented if the PKU mother follows a low phenylalanine diet during
pregnancy.
b) can occur in the fetus of a woman who has PKU.
c) can occur even though the fetus is heterozygous for PKU.
d) All of the above are true.
e) None of the above are true.
115.
The defect that results in sickle cell anemia is:
a) an amino acid substitution in hemoglobin.
b) the inability of the body to produce hemoglobin.
c) the inability of hemoglobin to dissolve oxygen.
d) the inability of hemoglobin to release oxygen.
e) None of the above
116.
When a cell undergoes mitosis,
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a) the daughter cells have identical genes.
b) the daughter cell has genes identical to those of the mother cell that produced it.
c) the amount of cytoplasm in the mother cell and in each of the daughter cells is equal.
d) there is an exact duplication and division of all of the organelles between daughter cells.
e) both a and b, but not c or d
117.
Which of the following is NOT an example of a clone?
a) a pair of identical twins
b) a group of rooted plant cuttings from a single plant
c) the cells produced by the asexual reproduction of a single-celled organism
d) the offspring produced by a single set of parents
e) all of the above
118.
Which of the following statements is true?
a) Once a person reaches maturity, cell division stops unless it is to repair a wound.
b) Cell division in an adult signifies cancer.
c) Some specific cells throughout the body retain the ability to divide and replace
themselves.
d) Growth continues on throughout the life of an adult human.
e) All cells retain the ability to divide even after the organism reaches maturity.
119.
Strictly speaking, mitosis and meiosis are divisions of the
a) nucleus.
b) cytoplasm.
c) chromosomes.
d) only a and c
e) a, b, and c
120.
Eukaryotic DNA molecules
a) have no proteins.
b) have small amounts of protein at each end of the DNA molecules.
c) have large amounts of protein at each end of the DNA molecules.
d) have small amounts of protein dispersed among the DNA molecules.
e) have large amounts of protein dispersed among the DNA molecules.
121.
Which process is absolutely necessary for sexual reproduction to occur in a life
cycle but is not necessarily required for organisms that only reproduce asexually?
a) prokaryotic fission
b) mitosis
c) meiosis
d) cytokinesis
e) karyokinesis
122.
Chromatids that are attached at the centromere are called what kind of
chromatids?
a) mother
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b) daughter
c) sister
d) programmed
e) either a or b, but not c or d
123.
The number of DNA molecules present in a duplicated chromosome is
a) 1
b) undetermined.
c) half that of an unduplicated chromosome.
d) 2.
e) 4.
124.
In which of the stages below does each chromosome consist of two DNA
molecules?
I. metaphase III. prophase
II. telophase
IV. anaphase
a) III and IV
b) I, III, and IV
c) I and III
d) I, II, and III
e) I, II, III, and IV
125.
When a eukaryotic cell divides, the daughter cells
a) manufacture all the organelles from material in the cytoplasm.
b) receive enough of the organelles to start up the new cells and produce additional
organelles as needed.
c) produce individual organelles that attach to the spindle fibers and are distributed just like
chromosomes.
d) produce an equal number of organelles distributed to each cell.
e) get cellular organelles by an unknown process.
126.
The chromatids detach from one another and become visibly separate
chromosomes during
a) anaphase.
b) metaphase.
c) interphase.
d) prophase.
e) telophase.
127.
The entire process of producing two cells from one cell
a) starts with prophase.
b) ends with cytokinesis.
c) results in the equal distribution of organelles between cells.
d) occurs only in multicellular organisms.
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e) both a and b, but not c or d
128.
Which of the following will NOT develop into a gamete?
a) spermatogonium
b) polar bodies
c) oocyte
d) spermatid
e) secondary spermatocyte
129.
Polar bodies
a) are dumping places for excess genetic material.
b) have no known biological function.
c) are produced by meiosis.
d) will serve as the gametes if something happens to the egg.
e) all but d are correct
130.
Sperm are formed from the direct maturation of
a) sperm mother cells.
b) spermatids.
c) spermatogonial cells.
d) primary spermatocytes.
e) secondary spermatocytes.
131.
The mature ovum is produced by maturation of the
a) oogonium.
b) primary oocyte.
c) secondary polar body.
d) polar body I.
e) none of the above
132.
Which of the following genotypes is homozygous?
a) AaBB
b) aABB
c) aaBB
d) aaBb
e) AaBb
133.
The most accurate description of an organism with genotype AaBb is
a) homozygous dominant.
b) heterozygous.
c) heterozygous dominant.
d) homozygous recessive.
e) heterozygous recessive.
134.
Gene A occurs on chromosome #5, gene B occurs on chromosome #21. Therefore,
these two portions of the chromosomes CANNOT be
a) genes.
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b) dominant.
c) loci.
d) alleles.
e) recessive.
135.
Which organism did Mendel utilize to work out the laws of segregation and
independent assortmen
a) the fruit fly
b) Neurospora
c) the garden pea
d) the chicken
e) E. coli
136.
Mendel's study of genetics differed from his contemporaries' studies because he
a) used only pure-breeding parents.
b) examined several different traits at the same time.
c) kept careful records and analyzed the data statistically.
d) worked on plants rather than animals
e) confirmed the blending theory of inheritance.
137.
The chromosomes are moving to opposite poles during
a) anaphase.
b) metaphase.
c) interphase.
d) prophase.
e) telophase.
138.
Who proposed the law of independent assortment?
a) Morgan
b) Mendel
c) Sturtevant
d) Weismann
.
e) Flemming
139.
Which of the following descriptions of Mendel is INCORRECT?
a) He was simply lucky to work out the laws of genetics.
b) He focused on contrasting phenotypic characteristics.
c) He demonstrated that the blending theory of inheritance was wrong.
d) He kept exact mathematical data and was the first scientist to utilize numerical analysis of
results.
e) He was a monk, a science teacher, and a gardener.
140.
Which of the following is NOT associated with meiosis?
a) reduction of number of chromosomes
b) somatic cells
c) sexual reproduction
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d) sperm and egg
e) germ cells
141.
Which of the following statements about Mendel is false?
a) He did not know about chromosomes.
b) He was not aware of Darwin's theory of evolution.
c) He was well trained in agriculture and mathematics.
d) His work was widely recognized even though it did not produce as much
controversy as Darwin's work.
e) His work established a basic understanding of the laws of heredity.
142.
Mendel found that pea plants expressing a recessive trait of a trait.
a) were pure-breeding.
b) appeared only in the first generation of a cross between two pure-breeding plants
expressing contrasting forms
c) disappeared after the second generation.
d) could be produced only if one of the parents expressed the recessive trait.
e) none of the above
143.
Hybrid organisms produced from a cross between two pure-breeding organisms
belong to which generation?
a) PI
b) HI
c) AI
d) FI
e) F2
144.
If R is dominant to r, the offspring of the cross of RR with rr will
a) be homozygous.
b) display the same phenotype as the RR parent.
c) display the same phenotype as the rr parent.
d) have the same genotype as the RR parent.
e) have the same genotype as the rr parent.
145.
If short hair (L) is dominant to long hair (l), animals LL and Ll have the same
a) parents.
b) genotypes.
c) phenotypes.
d) alleles.
e) Genes
146.
According to Mendel, what kind of genes "disappear" in FI pea plants?
a) sex-linked
b) dominant
c) recessive
d) codominant
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e) lethal
147.
If tall (D) is dominant to dwarf (d), and two homozygous varieties DD and dd are
crossed, then what kind of progeny will be produced?
a) all intermediate forms
b) all tall
c) all dwarf
d) ½ tall, ½ dwarf
e) ¾ tall, ¼ dwarf
148.
If two genes are on the same chromosome,
a) crossing over occurs frequently.
b) they assort independently.
c) they are in the same linkage group.
d) they are segregated during meiosis.
e) an inversion will usually occur.
149.
In genetic analyses, researchers know that linkage of genes will introduce
exceptions to the principle of dominance.
a) segregation.
b) recessiveness.
c) independent assortment.
d) chromosomal inheritance.
150.
If two genes are almost always found in the same gamete,
a) they are located close together on the same chromosome.
b) they are located on nonhomologous chromosomes.
c) they are located far apart on the same chromosome.
d) they are found on the sex chromosome.
e) all except c
151.
Which of the following statements is correct?
a) The ability to map the position of genes on a chromosome depends on the frequency of
crossing over.
b) The map distances between genes on a chromosome map mark only relative distances
between them, depending on crossover frequency.
c) The chance of a crossover only partially depends upon the distance between genes.
d) The map distance in a chromosome map refers to actual physical distance between genes.
e) both a and b
152.
Which of the following would be the least satisfactory organism for genetic
research?
a) humans
b) bacteria
c) corn
d) fruit flies
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e) peas
153.
In a pedigree chart, a male showing the specific trait being studied is indicated by
a
a) darkened square.
b) clear square.
c) darkened diamond.
d) clear triangle.
e) darkened circle.
154.
In karyotyping, individual chromosomes may be distinguished from others by
a) a comparison of chromosome lengths.
b) bands produced on chromosomes by differential staining.
c) the position of centromeres.
d) all of the above
e) none of the above
155.
In a pedigree chart, a female who does not demonstrate the trait being studied is
represented by a
a) darkened square.
b) clear diamond.
c) clear circle.
d) darkened triangle.
e) darkened oval.
156.
Each of the following would be classified as a genetic disorder except ____,
which is an abnormality.
a) albinism
b) webbed toes
c) hemophilia
d) Down syndrome
e) XYY
157.
An autosomal recessive disorder
a) requires that only one parent be a carrier.
b) displays its symptoms only in heterozygotes.
c) is more frequent in males than females.
d) will appear only in children of parents who both carry the gene.
e) is dominant in females.
158.
Pairs of identical units formed by chromosome duplication are called ___, and
are held together by ______
a) daughter chromosomes, hydrogen bonding
b) daughter chromatids, spindle fibers
c) sister chromosomes, histone proteins
d) sister chromatids, centromeres
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e) Both a and b are true.
159.
The probability of producing a normal child by two parents who are carriers for
an autosomal recessive disorder is
a) 50 percent.
b) 0 percent.
c) 100 percent.
d) 25 percent.
e) 75 percent.
160.
Galactosemia
a) is an X-linked recessive trait expressed more commonly in males.
b) occurs more frequently in some ethnic groups than others.
c) is an autosomal recessive inheritance.
d) must be homozygous to be expressed.
e) both c and d
161.
Like many genetic disorders, galactosemia is a disruption of a metabolic pathway
due to a malfunctioning
a) reactant.
b) cofactor.
c) enzyme.
d) energy source.
e) product.
162.
Which of the following diseases could be eliminated in one generation if everyone
that develops or will develop the disease could be sterilized or persuaded not to have
children?
a) hemophilia
b) albinism
c) sickle-cell anemia
d) galactosemia
e) Huntington's disorder
163.
_____ refers to multiple independent pairs of genes having similar and additive
effects on the same characteristic.
a) Codominance
b) Epistasis
c) Polygenic inheritance
d) Complete dominance
e) Additive dominance
164.
The work with sickle-cell anemia resulted in
a) an understanding of all metabolic disorders.
b) a cure for sickle-cell anemia.
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c) a change of the one gene, one enzyme hypothesis to one gene, one polypeptide
hypothesis.
d) the foundation for blood typing and transfusion.
e) both a and b
165.
Research on nutrient requirements in bread mold led to the idea that one gene
specifies the makeup of one
a) amino acid.
b) enzyme.
c) polypeptide.
d) both b and c are correct
e) a, b, and c are correct
166.
A chromosome's gene sequence that was ABCDEFG before modification and
ABCDLMNOP afterward is an example of
a) inversion.
b) deletion.
c) duplication.
d) translocation.
e) aneuploidy.
167.
A chromosome's gene sequence that was ABCDEFG before modification and
ABCDCDEFG afterward is an example of
a) inversion.
b) deletion.
c) duplication.
d) translocation.
e) aneuploidy.
168.
A chromosome that has been broken and rejoined in a reversal sequence has
undergone
a) inversion.
b) deletion.
c) duplication.
d) translocation.
e) aneuploidy.
169.
Chromosomal aberrations can be produced by exposure to
a) viruses.
b) radiation.
c) various chemicals.
d) a and b only
e) a, b, and c
170.
A chromosome's gene sequence that was ABCDEFG before damage and ABCFG
after is an example of
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a) inversion.
b) deletion.
c) duplication.
d) translocation.
e) aneuploidy.
171.
A chromosome's gene sequence that was ABCDEFG before damage and
ABFEDCG after is an example of
a) inversion.
b) deletion.
c) duplication.
d) translocation.
e) aneuploidy.
172.
Certain human cancer cells may demonstrate which of the following?
a) Deletion
b) Inversion
c) Translocation
d) Duplication
e) none of the above
173.
Which of the following is a transfer of genes between non-homologous
chromosomes?
a) crossing over
b) aneuploidy
c) trisomy
d) translocation
e) duplication
174.
Polyploidy is more common in plants than animals because
a) diploid gametes are more common in plants.
b) sterile plants can reproduce asexually.
c) plants generally do not have sex chromosomes.
d) plants can self-fertilize.
e) all of the above
175.
Queen Victoria
a. was a carrier of hemophilia.
b. had a hemophilic parent.
c. had hemophilia.
d. married a man with hemophilia.
e. both b and d
176.
In cocker spaniels, black coat color (B) is dominant over red (b), and solid color
(S) is dominant over spotted (s). If a red male was crossed with a black female to produce
a red spotted puppy, the genotypes
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a) Bb Ss x Bb Ss
b) bb Ss x Bb Ss.
c) bb ss x Bb Ss.
d) bb Ss x Bb ss.
e) Bb ss x Bb ss.
177.
Genes are
a) located on chromosomes.
b) inherited in the same way as chromosomes.
c) arranged in linear sequence on chromosomes.
d) assorted independently during meiosis.
e) all of the above
178.
Chromosomes other than those involved in sex determination are known as
a) nucleosomes.
b) heterosomes.
c) alleles.
d) autosomes.
e) liposomes.
179.
Sex chromosomes
a) determine gender.
b) vary from one sex to another.
c) carry some genes that have nothing to do with sex.
d) were unknown to Mendel.
e) all of the above
180.
DNA coding regions that affect the same trait are called
a) homologues.
b) alleles.
c) autosomes.
d) loci.
e) gametes.
181.
The location of a gene on a chromosome is its
a) centromere.
b) locus.
c) autosome.
d) allele.
e) none of the above
182.
A karyotype
a) compares one set of chromosomes to another.
b) is a visual display of chromosomes arranged according to size.
c) is a photograph of cells undergoing mitosis during anaphase.
d) of a normal human cell shows forty-eight chromosomes.
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e) cannot be used to identify individual chromosomes beyond the fact that two
chromosomes are homologues.
183.
How have the difficulties associated with studies of human genetics in part been
overcome?
a) By selective mating within some communities.
b) By applying the laws of probability to data obtained from a large sample of
individuals.
c) By applying artificial selection to some human genetic traits.
d) Both a and b are true.
e) Both a and c are true.
184.
Karyotyping is usually done using what kind of cells?
a) muscle
b) blood
c) cartilage
d) sex
e) epidermal
185.
Which chemical is used to keep chromosomes from separating during metaphase?
a) Giemsa stain
b) acetone
c) colchicine
d) alcohol
e) formaldehyde
186.
Colchicine interferes with the function of
a) microtubules.
b) ribosomes.
c) centrioles.
d) centromeres.
e) chromosomes.
187.
Karyotype analysis
a) is a means of detecting and reducing mutagenic agents.
b) is a surgical technique that separates chromosomes that have failed to segregate properly
during meiosis II.
c) is used in prenatal diagnosis to detect chromosomal mutations and metabolic
disorders in embryos.
d) substitutes defective alleles with normal ones.
e) all of the above
188.
Karyotyping involves taking pictures of chromosomes during
a) prophase.
b) telophase.
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c) metaphase.
d) interphase.
e) anaphase.
189.
With respect to chromosomes, the difference between normal human males and
females is defined by which of the following?
a) In females one X is deleted.
b) Females possess one X and one Y.
c) In males an X is replaced by a Y.
d) Females have three X's.
e) Males have two X's and a Y.
190.
Which of the following statements is false?
a) The SRY gene is absent in all females.
b) The SRY gene apparently is the gene that controls the development of male sexuality.
c) The development of maleness is by default because males lack two X chromosomes.
d) Maleness develops in the embryo before femaleness.
e) There is no difference in external genitalia of males or females until four weeks after
conception when the genes determining sex begin to be expressed.
191.
Concerning the sex chromosomes, which of the following is correct?
a) The Y chromosome carries a greater number of nonsexual traits.
b) X and Y are different in size but carry nearly equal numbers of genes.
c) The X chromosome carries more genes for nonsexual traits.
d) The X chromosome carries only gender-related genes.
e) The X chromosome carries the TDF gene.
192.
Who was the first to use fruit flies in genetics experiments?
a) Morgan
b) Mendel
c) Sturtevant
d) Weismann
e) Flemming
193.
In his experiments with Drosophila melanogaster, Morgan demonstrated that
a) fertilized eggs have two sets of chromosomes, but eggs and sperm have only one set in
each gamete.
b) aneuploidy exists in karyotypes that have undergone deletions and inversions in specific
chromosomes.
c) colchicine is effective in producing polyploidy in F2 generations.
d) certain genes are located only on an X chromosome and have no corresponding
alleles on the Y chromosome.
e) all of the above
194.
An X-linked carrier is a
a) homozygous dominant female.
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b) heterozygous female.
c) homozygous recessive female.
d) homozygous male.
e) heterozygous male.
195.
A human X-linked gene is a
a) found only in males.
b) more frequently expressed in females.
c) found on the Y chromosome.
d) transmitted from father to son.
e) found on the X chromosome.
196.
Gene mapping
a) applies only to genes located on the same chromosomes.
b) represents actual physical distance between genes.
c) is based upon the frequency of crossing over.
d) can be accomplished only by using the sex chromosomes.
e) Two of the above choices are correct.
197.
Which of the following statements is false?
a) Crossing over tends to reduce the frequency that two linked genes are inherited together.
b) Independent assortment of homologous chromosomes during meiosis increases variation.
c) Crossing over leads to variation.
d) Abnormal number or structure of chromosomes may influence the course of evolution.
e) The closer together genes are found on a chromosome the greater is the chance that
crossing over will occur between them.
198.
All of the genes located on a given chromosome constitute
a) karyotype.
b) bridging cross.
c) wild-type allele.
d) linkage group.
e) none of the above.
199.
The incidence of cancer increases dramatically with age because
a) the Ras protein is more likely to be hyperactive after age sixty.
b) proteasomes become more active with age.
c) as we age, normal cell division inhibitors cease to function.
d) the longer we live, the more mutations accumulate.
e) tumor-suppressor genes are no longer able to repair damaged DNA.
200.
Which of these is not a carcinogen?
a) testosterone
b) cigarette smoke
c) UV light
d) fat
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e) all of the above are carcinogens
SECTION II
1.
a)
b)
c)
d)
e)
2.
a)
b)
c)
d)
e)
3.
a)
b)
c)
d)
e)
4.
a)
b)
c)
d)
e)
5.
a)
Symptoms of phenylketonuria (PKU) may be minimized or suppressed by a diet low in
serine.
glycine.
phenylalanine.
proline.
glutamic acid.
Sickle-cell anemics should avoid
phenylalanine.
strenous activity.
high oxygen conditions.
sunlight.
diet colas.
Amniocentesis involves sampling
the fetus directly.
the fetal cells floating in the amniotic fluid.
sperm.
blood cells.
placental cells.
Amniocentesis is
a surgical means of repairing deformities.
a form of chemotherapy that modifies or inhibits gene expression or the function of gene
products.
used in prenatal diagnosis to detect chromosomal mutations and metabolic
disorders in embryos.
a form of gene replacement therapy.
all of the above
In prenatal diagnosis, the newest procedure that can be performed early in pregnancy
involves sampling the
amnion.
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b)
c)
d)
e)
6.
allantois.
chorion.
yolk sac.
umbilical cord.
The most recent technique for analyzing the genetics of the unborn child involves the
sampling of
a) the fetus directly.
b) cells in the amniotic fluid.
c) material from the allantois.
d) the chorionic villi.
e) yolk sac material.
7. Four of the five answers listed below describe sets of chromosomes with extra numbers.
Select the exception.
a) polyploid
b) tetraploid
c) diploid
d) triploid
e) allopolyploid
8. Four of the five answers listed below are organisms widely used in genetic research.
Select the exception.
a) peas
b) fruit flies
c) Neurospora
d) dogfish shark
e) E. coli
9. Which of the following is the most precise hypothesis about gene action?
a) One gene controls one enzyme.
b) Human metabolic defects may arise from absent or defective enzymes in a metabolic
pathway.
c) One gene controls one polypeptide.
d) Genes code for proteins in general, not just enzymes.
e) One gene codes for the amino acid sequence of one polypeptide chain.
10. DNA from bacteria differs from DNA in humans in which of the following ways?
a) base composition
b) sugar-phosphate linkage
c) nucleotide sequence
d) bonding of the helix
e) all of the above
11. A linear stretch of DNA that specifies the sequence of amino acids in a polypeptide is
called a(n)
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a) codon.
b) intron.
c) messenger.
d) gene.
e) enzyme.
12. The DNA molecule usually is made up of how many strands?
a) 1
b) 2
c) 3
d) 6
e) 12
13. Molecules carry protein-assembly instructions from the nucleus to the cytoplasm.
a) Template DNA
b) Messenger RNA
c) Transfer RNA
d) Ribosomal RNA
e) all of the above
14. The RNA molecule is made up of how many strands?
a) 1
b) 2
c) 3
d) 6
e) 12
15. The "central dogma" of molecular biology
a) explains the structural complexity of genes.
b) describes the flow of information.
c) is based upon the role of proteins in controlling life.
d) does not explain how genes function.
e) explains evolution in terms of molecular biology.
16. The changing of a business letter from shorthand to typewritten copy is analogous to
a) translation of mRNA.
b) transcription of DNA.
c) protein synthesis.
d) deciphering the genetic code.
e) replication of DNA.
17. All the different kinds of RNA are transcribed in the
a) mitochondria.
b) cytoplasm.
c) ribosomes.
d) nucleus.
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e) endoplasmic reticulum.
18. The form of RNA that carries the code from the DNA to the site where the protein is
assembled is called
a) messenger RNA.
b) nuclear RNA.
c) ribosomal RNA.
d) transfer RNA.
e) structural RNA.
19. The nitrogenous base found in DNA but not in RNA is
a) adenine.
.
b) cytosine.
c) guanine.
d) uracil.
e) thymine.
20. DNA and RNA are alike in
a) the pentose sugar.
b) all the nitrogenous bases used to assemble the genetic code.
c) the number of strands.
d) their function in genetics.
e) none of the above
21. Which substance is found in RNA but not in DNA?
a) thymine
b) deoxyribose
c) uracil
d) guanine
e) cytosine
22. The nitrogenous base found in RNA but not in DNA is
a) adenine.
b) cytosine.
c) guanine.
d) uracil.
e) thymine.
23. Transfer RNA differs from other types of RNA because it
a) transfers genetic instructions from cell nucleus to cytoplasm.
b) specifies the amino acid sequence of a particular protein.
c) carries an amino acid at one end.
d) contains codons.
e) none of the above
24. The wobble effect pertains to the matching of
a) codons with anticodons.
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b) codons with exons.
c) exons with introns.
d) template DNA with messenger RNA.
e) messenger RNA with ribosomal RNA.
25. Eukaryotic ribosomes function as
a) a single unit.
b) two-part units.
c) three-part units.
d) four-part units.
e) a multidivisional unit.
26. All mRNA transcripts begin with
a) methionine.
b) a ribosome.
c) AUG.
d) the P site.
e) an anticodon.
27. Which of the following statements is false?
a) In chain elongation, the amino acids are added to the chain according to the sequence in
the messenger RNA.
b) The messenger RNA molecule is stationary and series of ribosomes called polysomes
travel along the molecule manufacturing series of polypeptides at the same time.
c) The shape of transfer RNA molecules is uniform and is maintained by hydrogen bonds.
d) Enzymes found in the ribosome catalyze the formation of the bonds in the new
polypeptide.
e) None of the above statements is false.
28. The maximum number of tRNAs that can be on one ribosome at one time is
a) 2.
b) 3.
c) 43
d) unlimited.
e) unknown.
29. A polysome is
a) one of the units of a ribosome.
b) the nuclear organelle that synthesizes RNA.
c) an organelle that functions similarly to a ribosome during meiosis.
d) the two units of a ribosome considered together.
e) an mRNA molecule with several ribosomes attached.
30. A gene mutation
a) is a change in the nucleotide sequence of DNA.
b) may be caused by environmental agents.
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c) may arise spontaneously.
d) can occur in any organism.
e) all of the above
31. Which of the following statements is true?
a) Gene mutations occur independently of each other.
b) Gene mutations are relatively rare.
c) The reason that two antibiotics may be given at one time is due to the very remote
possibility that two gene mutations could occur in the same cell at the same time.
d) Mutations are random; that is, it is impossible to predict exactly when a specific gene will
mutate but an expected frequency can be assigned.
e) all of the above
32. Which event may occur in all viruses, prokaryotes, and eukaryotes?
a) duplication
b) aneuploidy
c) translocation
d) mutation
e) all of the above
33. Mutations can be
a) random.
b) beneficial.
c) lethal.
d) heritable.
e) all of the above
34. Frameshift mutations may involve
a) substitution of nucleotides.
b) substitution of codons.
c) substitution of amino acids.
d) addition or deletion of one to several base pairs.
e) all of the above
35. Sickle-cell anemia has been traced to what type of mutation?
a) frameshift
b) transposable element
c) mutagenic
d) base-pair substitution
e) viral
36. The difference between normal and sickle-cell hemoglobin is based upon
a) the number of amino acids in the molecule.
b) the substitution of one amino acid for another.
c) the number and orientation of the amino acid chains attached to the heme portion of the
molecule.
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d) the number of oxygen molecules that can be carried.
e) the type of bone marrow that produces it.
37. In a mutation,
a) the new codon may specify a different amino acid but may not change the function of the
new protein produced.
b) the new codon may specify the same amino acid as the old codon.
c) the new codon and resulting amino acid may destroy the function of the protein specified.
d) All of the above may be true.
38. Polyploidy
a) can occur naturally.
b) occurs when there are more than two sets of chromosomes.
c) can be artificially induced by colchicine.
d) is responsible for some of our major foods.
e) all of the above
39. Triploids
a) are usually sterile.
b) are produced by the fusion of a diploid and a haploid.
c) cannot undergo meiosis.
d) are polyploids.
e) all of the above
40. Which of the following does NOT belong with the other four?
a) inversion
b) polyploidy
c) deletion
d) duplication
e) translocation
41. The condition occurring when an organism has a 2n + 1 chromosome composition is
known as
a) monosomy.
b) trisomy.
c) diploid.
d) aneuploidy.
e) both b and d
42. If a gamete is missing one chromosome,
a) the chromosome number is expressed as 2n -1.
b) then one chromosome is without its homologue.
c) the condition is called monosomy.
d) only a and c
e) a, b, and c
43. If nondisjunction occurs during meiosis,
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a) the resulting sex cells will be heterogametes.
b) one-half of the resulting cells will exhibit trisomy and the other half monosomy.
c) diploid cells will be produced.
d) all gametes would lack a chromosome and these gametes would be infertile.
44. The failure of chromosomes to separate during mitosis or meiosis is called
a) genetic displacement.
b) trisomy.
c) crossing over.
d) nondisjunction.
e) disjunction.
45. Which of the following is different from the other four?
a) nondisjunction
b) duplication
c) inversion
d) deletion
e) translocation
46. Down syndrome involves trisomy
a) 3.
b) 5.
c) 15.
d) 19.
e) 21.
47. In Down syndrome,
a) as the age of the mother increases, the chance of the defect occurring in the unborn
children increases.
b) the father seems to have very little influence on the defect.
c) most embryos abort before complete term.
d) a person with the defect cannot have a normal child.
e) none of the above
48. Syndrome means
a) a chromosome disorder.
b) a simple genetic disease.
c) a set of symptoms that occur together.
d) an incurable disease.
e) a rare inborn defect.
49. Which of the following designates a normal human female?
a) XXY
b) XY
c) XX
d) XYY
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e) XO
50. Which of the following conditions is characterized by a karyotype with forty-five
chromosomes?
a) Turner syndrome
b) Down syndrome
c) testicular feminization syndrome
d) Klinefelter syndrome
e) cri-du-chat
51. Suppose that a hemophilic male (X-linked recessive allele) and a female carrier for the
hemophilic trait have a non-hemophilic daughter with Turner syndrome. Non-disjunction
could have occurred in
a) both parents.
b) neither parent.
c) the father only.
d) the mother only.
e) none of the above
52. The sex chromosome composition of a person with Turner syndrome is
a) XXX.
b) XO.
c) XXY.
d) XYY.
e) none of the above
53. Nondisjunction involving the X chromosomes may occur during oogenesis and produce
two kinds of eggs. If normal sperm fertilize these two types, which of the following pairs
of genotypes are possible?
a) XX and XY
b) XXY and XO
c) XYY and XO
d) XYY and YO
e) none of the above
54. Which of the following designates a normal human male?
a) YY
b) XX
c) XY
d) XO
e) XYY
55. The sex chromosome composition of a person with Klinefelter syndrome is
a) XXX.
b) XO.
c) XXY.
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d) XYY.
e) none of the above.
56. A genetic abnormality that may result in sterile males with mental retardation or breast
enlargement is
a) XXY.
b) XYY.
c) Turner syndrome.
d) Down syndrome.
e) none of the above
57. Males that tend to be taller than average and show mild mental retardation may be
designated
a) XXY.
,
b) XYY.
c) Turner syndrome.
d) Down syndrome.
e) none of the above
58. If a study of several pedigrees demonstrated that two parents express a characteristic
and none of their children express it, then the trait is controlled by
a) a codominant gene.
b) a simple dominant gene.
c) a recessive gene.
d) a sex-linked gene.
e) No conclusion can be drawn.
59. If a study of several pedigrees demonstrated that two parents are normal but their
children express a trait, then the trait is controlled by a
a) codominant gene.
b) simple dominant gene.
c) recessive gene.
d) sex-linked gene.
e) No conclusion can be drawn.
60. Aneuploidy would describe all of the following except
a) Turner syndrome.
b) Klinefelter syndrome.
c) translocation.
d) XYY
e) Down syndrome.
61. Which of the following is NOT true?
a) Down syndrome is an example of aneuploidy.
b) Human polyploids are lethal.
c) Most euploidy embryos miscarry.
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d) The rate of aneuploidy is higher in humans than in other mammals.
e) On the average, one out of two newly fertilized eggs is an aneuploid.
62. Which is NOT a chromosomal abnormality?
a) Deletion
b) extra chromosomes
c) translocation (exchange of parts between nonhomologues)
d) crossing over
e) inversion
63. Treatments for genetic disorders currently involve
a) substituting normal for defective parents.
b) substituting normal for defective genes.
c) supplying a missing gene.
d) supplying missing enzymes or gene products.
e) all of the above
64. Phenotypic treatments for genetic disorders include
a) preventing the disorders in the carriers.
b) eliminating the defective gene.
c) preventing a disorder from being passed on.
d) preventing a disorder from being expressed
e) all of the above
65. Phenotypic treatments
a) may increase the number of defective genes in a population.
b) do not affect the number of defective genes in a population.
c) decrease the number of defective genes in a population.
d) are the ultimate cures for genetic disorders.
e) have no biological value for either the individual or the population.
66. PKU can be detected by
a) karyotyping.
b) urine analysis.
c) blood tests.
d) saliva tests.
e) both band c
67. Gene replacement therapy
a) has not yet been used successfully with mammals.
b) is a surgical technique that separates chromosomes that have failed to segregate properly
during meiosis II.
c) has been used successfully to treat victims of Huntington's disorder by removing the
dominant damaging autosomal allele and replacing it with a harmless one.
d) substitutes defective alleles with normal ones.
all of the above
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68. Three of the four answers listed below are different forms of a class of nucleic acids.
Select the exception.
a) template
b) ribosomal
c) messenger
d) transfer
69. Three of the four answers listed below are involved in gene action. Select the exception.
a) replication
b) transcription
c) translation
d) polymerization
70. Four of the five answers listed below are steps in the process of transcription. Select the
exception.
a) cap put on one end
b) introns snipped out
c) action by DNA polymerase
d) poly-A tail placed on one end
e) exons spliced together
71. Four of the five answers listed below are related pairings. Select the exception.
a) double-stranded DNA - messenger RNA
b) purine - pyrimidine
c) codon - anticodon
d) small subunit -large subunit
e) promoter - terminator
72. Four of the five answers listed below describe changes at the chromosomal level. Select
the exception.
a) base substitution
b) duplication
c) translocation
d) deletion
e) inversion
73. Four of the five answers listed below are chromosomal abnormalities. Select the
exception.
a) translocation
b) elongation
c) duplication
d) deletion
e) inversion
74. Four of the five answers listed below are sources of genetic variation. Select the
exception.
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a) crossing over
b) mutation
c) asexual reproduction
d) chromosome aberration
e) sexual reproduction
75. Four of the five answers listed below are components of a nucleotide. Select the
exception.
a) pentose sugar
b) amino acid
c) pyrimidine
d) phosphate group
e) purine
76. Four of the five answers listed below are related by a common number. Select the
exception.
a) number of nucleotides in a codon
b) number of building blocks (parts) in a nucleotide
c) number of stop codons
d) number of types of DNA
e) number of types of RNA
77. Four of the five answers listed below are conditions caused by chromosomal
nondisjunction. Select the exception.
a) Down syndrome
b) Huntington's disorder
c) Turner syndrome
d) Klinefelter syndrome
e) trisomy 21
78. Four of the five answers listed below are therapeutic measures applied to affected
individuals. Select the exception.
a) prenatal diagnosis
b) chemotherapy
c) surgical correction
d) diet modification
e) environmental adjustment
79. Four of the five answers listed below are methods used to reduce the number of defective
genes in a population. Select the exception.
a) genetic counseling
b) gene replacement
c) mutagen reduction
d) diet modification
e) genetic screening
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80. Four of the five answers listed below are caused by recessive genes. Select the exception.
a) Huntington's disorder
b) phenylketonuria
c) color blindness
d) hemophilia
e) albinism
81. Friedrich Miescher is credited with
a) proposing DNA as the hereditary material.
b) finding a cure for pneumonia.
c) telling us that A = T and G = C.
d) discovering nucleic acids.
e) only a and d are correct
82. When Fred Griffith injected mice with a mixture of dead, pathogenic, encapsulated S
cells and living unencapsulated R cells of Streptococcus pneumoniae, he discovered that
a) the previously harmless strain (S) had inherited the ability to kill mice.
b) the dead mice teemed with living pathogenic (R) cells.
c) the killer strain (R) was encased in a protective capsule.
d) b and c above
e) all of the above
83. Fred Griffith's experiments
a) produced a vaccine against bacterial pneumonia.
b) demonstrated that rough (R) bacteria cause pneumonia.
c) provided evidence that genetic material from one bacterial culture could be
transferred to another culture.
d) showed that rough bacteria injected into mice will be changed by the mice to smooth (S)
bacteria.
e) converted harmless smooth bacteria into lethal rough bacteria.
84. The significance of Fred Griffith's experiment in which he used two strains of
Streptococcus pneumoniae is that
a) the semiconservative nature of DNA replication was finally demonstrated.
b) it demonstrated that harmless cells had become permanently transformed through a
change in the bacterial hereditary system.
c) it established that pure DNA extracted from disease- causing bacteria transformed
harmless strains into killer strains.
d) it demonstrated that radioactively labeled bacteriophages transfer their DNA but not their
protein coats to their host bacteria.
e) all of the above
85. Which of the following statements is NOT true about Fred Griffith's experiments?
a) Mice injected with smooth (S) bacteria die.
b) Mice injected with heat-killed smooth bacteria die.
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c) Mice injected with heat-killed smooth bacteria and live rough (R) bacteria die.
d) Mice injected with rough bacteria live.
e) Smooth bacteria are transformed into harmless rough bacteria.
86. Which scientist(s) identified the transforming substance involved in changing rough (R)
bacteria to smooth (S)?
a) Avery
b) Griffith
c) Chargaff
d) Hershey and Chase
e) Pauling
87. Bacteriophages are
a) large bacteria.
b) pathogens (disease-producing bacteria).
c) viruses.
d) cellular components.
e) protistans.
88. The significance of the experiments in which 32P and 35S were used is that
a) the semiconservative nature of DNA replication was finally demonstrated.
b) it demonstrated that harmless bacterial cells had become permanently transformed through a
change in the bacterial hereditary system.
c) it established that pure DNA extracted from disease-causing bacteria transformed harmless
strains into killer strains.
d) it demonstrated that radioactively labeled bacteriophages transfer their DNA but not
their protein coats to their host bacteria.
e) none of the above
89. In the cycle of viral infection, which of the following is the last process to occur?
a) invasion of viruses into the body
b) replication of viral particles by bacteria
c) lysis of the bacteria
d) attachment of virus to bacteria
e) injection of nucleic acid into the bacteria
90. If a mixture of viruses labeled with radioactive sulfur and phosphorus is placed in a
bacterial culture,
a) the bacteria will absorb radioactive sulfur.
b) the bacteria will absorb radioactive phosphorus.
c) the bacteria will absorb both radioactive sulfur and phosphorus.
d) the bacteria will not absorb either sulfur or phosphorus.
e) the viruses will not attach to the bacteria.
91. Nucleic acid contains
a) sulfur.
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b)
c)
d)
e)
phosphorus.
potassium.
iron.
manganese.
92. Which of the following statements is false?
a) Protein molecules contain no phosphorus.
b) Hershey and Chase discovered that 35S and not 32P had been incorporated into the
hereditary system of the bacteria.
c) Bacteriophages are viruses that inject their nucleic acid genetic code into bacteria and use
the bacterial genetic apparatus to make viral proteins.
d) Each nucleotide is composed of a five-carbon sugar, a phosphate group, and either a purine
or pyrimidine.
e) Viruses are particles of nucleic acid encased in protein.
93. The experiments of which of the following researchers clearly distinguished DNA as the
hereditary material (as opposed to protein)?
a) Pauling
b) Hershey and Chase
c) Griffith
d) Watson and Crick
e) Avery
94. Sulfur is
a) found in proteins, but not nucleic acids.
b) a vital component of DNA.
c) found in nucleic acids but not proteins.
d) needed for bacteriophages to attach to bacteria.
e) needed for the enzyme that splits the wall of bacteria.
95. The building blocks of nucleic acids are
a) amino acids.
b) nucleotides.
c) pentose sugars.
d) phosphate groups.
e) nitrogenous bases.
96. Which of the following terms is NOT related to the other four?
a) amino acids
b) nucleotides
c) pentose sugars
d) phosphate groups
e) nitrogenous bases
97. A nucleotide may contain
a) a purine.
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b)
c)
d)
e)
a pentose.
a phosphate group.
a pyrimidine.
all of the above
98. Which scientist(s) discovered the basis for the base-pair rule, which states that the
amounts of adenine and thymine match, as do the amounts of cytosine and guanine?
a) Avery
b) Griffith
c) Chargaff
d) Hershey and Chase
e) Pauling
99. DNA varies from species to species in its
a) base-pair bonding.
b) relative amounts of nucleotide bases.
c) sequence of base pairs.
d) a and c only
e) b and c only
100. Mendel's single factor crosses led to which of the following rules of inheritance?
a) concept of dominance
b) law of segregation
c) support for the particulate theory of inheritance
d) all of the above
101. In a Chi square test of a genetic cross there are n different phenotypic classes in the
offspring. What is the value for the degrees of freedom for the test?
.
a) n
b) n-l
c) n + 1
d) 2n
e) none of the above
102. The pea plant, Pisum sativum, was used by Mendel as a model organism for which of the
following reason(s):
a) there were easily visible traits such as flower color and seed shape.
b) self-fertilization was possible.
c) it was relatively easy to grow.
d) all of the above are correct.
103. The observable characteristic of an organism is called its ___
a) genotype
b) phenotype
c) pedigree
d) allele
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e) none of the above
104. If an organism contains two identical alleles for the same trait, it is said to be which of
the following?
a) cross-fertilized
b) heterozygous
c) homozygous
d) a hybrid
e) none of the above
105. Two individuals who are heterozygous for a given trait are crossed. What will be the
phenotypic ratio of their offspring?
a) 75% will display the dominant trait, 25% will display the recessive trait
b) 100 % will display the recessive trait
c) 100% will be heterozygous individuals
d) 50% will display the dominant trait, 50% will display the recessive trait
e) all of the above are possible
106. In a two-factor cross, if two individuals who are heterozygous for both traits are crossed
with one another, what will be the phenotypic ratio of their offspring based on Mendel's work?
a) 3:1
b) 1:2:1
c) 9:3:3: 1
d) 15:1
e) 9:6:1
107. The Punnett square is best used for which of the following?
a) to predict the goodness of fit of observations to expectations
b) to conduct crosses of four or more traits
c) for pedigree analysis
d) to visualize the possible outcomes of one and two-factor Mendelian crosses
108. Which of the following is correct concerning a pedigree analysis?
a) it is useful when examining organisms that produce a small number of offspring
b) it is useful when ethical problems prohibit controlled matings
c) it is frequently used to study patterns of inheritance in humans
d) it can be used to determine if a trait is dominant or recessive
e) all of the above are correct
*For questions 109 to 113, match the events of MEIOSIS prophase I to it correct function.
109.
110.
111.
112.
113.
Diakinesis
Zygotena
Diplotena
Leptotena
Pachytena
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a)
b)
c)
d)
e)
Homologous chromosomes recognize each other by synapsis.
The chromosomes begin to condense, and are now visible using a microscope.
The stage in which crossing over occurs.
The synaptonemal complex disappears.
The final stage of prophase 1.
114. A testcross is always conducted between an individual whose genotype is unknown, and
which of the following?
a) a heterozygous individual
b) a homozygous dominant individual
c) a homozygous recessive individual
d) any of the above will work
115.
A reciprocal cross is used to determine which of the following?
a) if a trait is autosomal or sex-linked
b) the number of autosomal chromosomes
c) the dominance / recessive nature of a trait
d) the sex of the organism
e) none of the above
116.
Thoman Hunt Morgan's experiment with white-eyed Drosophila provided proof of
which of the following?
a) law of independent assortment
b) chromosomal theory of inheritance
c) theory of natural selection
d) law of segregation
e) none of the above
117.
An organism has 20 pairs of chromosomes at the start of mitosis, how many
chromosome pairs with each cell have at the end of mitosis?
a) 5
b) l0
c) 20
d) 40
118.
During which of the following stages of the cell cycle is the DNA of the organism
replicated?
a) prophase
b) anaphase
c) S phase
d) G2 phase
119.
Before the start of meiosis, on which of the following would the genetic material
be almost identical?
a) homologous chromosomes
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b) sister chromatids
c) non-sister chromatids of homologous chromosomes
d) none of the above
120.
During which of the following stages of meiosis does synapsis and crossing over
occur?
a) metaphase
b) cytokinesis
c) prophase I
d) telophase II
e) prophase II
121.
The Sry gene of humans displays which of the following patterns of inheritance?
a) X- linked
b) pseudoautosomal
c) autosomal
d) Y-linked
122.
A trait that has a different level of expression in males than females is an example
of which of the following?
a) sex-influenced inheritance
b) sex-limited inheritance
c) gene dosage
d) all of the above
e) none of the above
123.
Expressivity is most often associated with which of the following?
a) multiple allele systems
b) heterozygote advantage
c) incomplete penetrance
d) incomplete dominance
e) none of the above
124.
Coat color in rabbits and human blood groups are both examples of __ .
a) multiple allele systems
b) epistatic interactions
c) gene dosage
d) simple Mendelian inheritance
e) all of the above
125.
The most common allele in the population is called the ___
a) mutant allele
b) essential allele
c) dominant allele
d) wild-type allele
e) recessive allele
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126.
Phenotypic blending is the result of ____
a) incomplete dominance
b) incomplete penetrance
c) codominance
d) overdominance
127.
A heterozygote that has a selective advantage over the homozygous dominant
individual is an example of ____
a) gene interaction
b) codominance
c) temperature sensitive lethals
d) overdominance
128.
A trait that is only expressed in one sex of the species is an example of __ .
a) temperature-sensitive alleles
b) sex-influenced inheritance
c) sex-limited inheritance
d) X-linked inheritance
129.
Pseudodominance is the result of a(n) _____
a) inversion
b) translocation
c) deletion
d) duplication
130.
The chromosome number of an individual with non-familial Down's syndrome is
indicated as
a) 2n - l
b) 3n
c) 2n+ 1
d) n + 2
131.
Prader- Willi and Angelmans syndromes are a result of a(n), ____
a) inversion
b) translocation
c) deletion
d) duplication
132.
Liver cells in humans exhibit which of the following?
a) alloploidy
b) endopolyploidy
c) monoploidy
d) aneuploidy
For questions* 133 to 139, match each statement with the researcher who contributed the
information to our understanding of DNA.
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a) Avery, MacLeod, and McCarty
b) Hershey and Chase
c) Griffith
d) all of the above
133.
Discovered the process of transformation in bacteria. Ans.C
134.
Treated Streptococcus pneumoniae extracts with enzymes to further identify the
genetic material.
Ans.A
135.
Used Streptococcus pneumoniae as a model system.
136.
Used radioactively labeled phages to determine if DNA or protein was the genetic
material. ANS. B
137.
Used a bacteriophage (T2) as the model system. Ans B
138.
Demonstrated that the transforming principle from the experiments with
Streptococcus pneumoniae is DNA.
139.
Demonstrated that DNA is the genetic material of bacteriophage T2. Ans. B
140.
The backbone of DNA is made up of ____
a) deoxyribose sugar
b) purines
c) pyrimidines
d) phosphate groups
e) none of the above
141.
___ used X-ray crystallography data to provide the first evidence of the threedimensional structure of DNA.
a) Chargaff
b) Watson and Crick
c) Franklin
d) Griffith
142.
In a DNA nucleotide within a DNA strand, this is the component that can vary.
a) phosphate groups
b) phosphodiester bonds
c) sugar
d) type of base
e) none of the above vary
143.
This is the form of DNA most common in living cells.
a) A DNA
b) B DNA
c) triplex DNA
d) ZDNA
e) K DNA
144.
___ discovered the process of transformation in bacteria.
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a) Avery and colleagues
b) Griffith
c) Chargaff
d) Pauling
e) Franklin
145.
In their experiments with bacteriophage T2, Hershey and Chase labeled the D A
using -'
a) 15N
b) 35S
c) 32P
d) 3H
146.
__ demonstrated that the genetic material in bacteriophage T2 was DNA.
a) Watson and Crick
b) Avery and colleagues
c) Franklin
d) Hershey and Chase
e) Pauling
147.
The 5' to 3' configuration of DNA is called its ____ property.
a) complementary
b) A T/GC rule
c) directionality
d) antiparallel
148.
These were the first individuals to demonstrate that DNA is a double-helix.
a) Watson and Crick
b) Pauling
c) Franklin
d) Chargaff
149.
.The structural unit of a DNA strand is the _____
a) nucleoside
b) nucleotide
c) ribose sugar
d) purine
e) none of the above
150. From X-ray diffraction data, which of the following was determined about DNA?
a) The molecule had uniform diameter.
b) The molecule was long and narrow.
c) Part of the molecule repeated itself often.
d) The shape of the molecule could be spiral.
e) all of the above
151. Rosalind Franklin's research contribution was essential in
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a) establishing the double-stranded nature of DNA.
b) establishing the principle of base pairing.
c) establishing most of the principal structural features of DNA.
d) sequencing DNA molecules.
e) determining the bonding energy of DNA molecules.
152. Rosalind Franklin used which technique to determine many of the physical
characteristics of DNA?
a) transformation
b) transmission electron microscopy
c) density-gradient centrifugation
d) x-ray diffraction
e) all of the above
153. James Watson and Francis Crick
a) established the double-stranded nature of DNA.
b) confirmed the principle of base pairing.
c) explained how DNA's structure permitted it to be replicated.
d) proposed the concept of the double helix.
e) all of the above
154. In the bonding of nitrogenous bases,
a) adenine is paired with cytosine.
b) adenine is paired with guanine.
c) cytosine is paired with thymine.
d) guanine is paired with cytosine.
155. In the bonding of two nucleotides,
a) hydrogen bonds are used.
b) adenine and thymine bind together.
c) purines bind with pyrimidines.
d) double-ring nitrogenous bases connect to single-ring bases.
e) all of the above
156. The DNA molecule could be compared to a
a) hairpin.
b) ladder.
c) key.
d) globular mass.
e) flat plate.
157. In DNA, complementary base pairing occurs between
a) cytosine and uracil.
b) adenine and guanine.
c) adenine and uracil.
d) adenine and thymine.
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e) all of the above
158. Adenine and guanine are
a) double-ringed purines.
b) single-ringed purines.
c) double-ringed pyrimidines.
d) single-ringed pyrimidines.
e) amino acids.
159. If a purine bonded to a purine in DNA, the molecule would ___ in that region.
a) be constricted
b) be perfectly normal
c) lose a sugar-phosphate unit
d) unwind
e) bulge
160. In the comparison between a spiral staircase and a DNA molecule, the steps would
correspond to
a) sugars.
b) hydrogen bonds.
c) base pairs.
d) nucleotides.
e) phosphates.
161. In DNA molecules,
a) the nucleotides are arranged in a linear, unbranched pattern.
b) the nitrogenous bases are found on the outside of the molecule.
c) the sugar-phosphate pattern runs the same way on each DNA strand.
d) all of the above
e) none of the above
162. Which of the following statements is true?
a) The hydrogen bonding of cytosine to guanine is an example of complementary base
pairing.
b) Adenine always pairs up with guanine in DNA, and cytosine always teams up with thymine.
c) Each of the four nucleotides in a DNA molecule has the same nitrogen-containing base.
d) When adenine base pairs with thymine, they are linked by three hydrogen bonds.
e) In the DNA of all species, the amount of purines never equals the amount of pyrimidines.
163. Each DNA strand has a backbone that consists of alternating
a) purines and pyrimidines.
b) nitrogen-containing bases.
c) hydrogen bonds.
d) sugar and phosphate molecules.
e) amines and purines.
164. Who among the following was NOT involved in working out the structure of DNA?
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a) Avery
b) Watson
c) Wilkins
d) Franklin
e) Chargaff
165. The ultimate explanation for resemblances of traits from one generation to another is
a) gamete formation.
b) semiconservative DNA replication.
c) sexual reproduction.
d) protein synthesis.
e) bloodlines.
166. The appropriate adjective to describe DNA replication is
a) nondisruptive.
b) semiconservative.
c) progressive.
d) natural.
e) lytic.
167. Replication of DNA
a) produces RNA molecules.
b) produces only new DNA.
c) produces two molecules, each of which is half-new and half-old DNA joined
lengthwise to each other.
d) generates excessive DNA, which eventually causes the nucleus to divide.
e) is too complex to characterize.
168. DNA strands serve as which of the following during DNA synthesis?
a) replicate
b) substitute
c) template
d) source of nucleotides
e) all of the above
169. After three replications of a single DNA molecule, what percent of the resulting double
helices contain one strand of the "original" DNA?
a) 0 percent
b) 25 percent
c) 50 percent
d) 75 percent
e) 100 percent
170. The primary function of DNA ligase is to
a) cut the two strands of the DNA molecule prior to replication.
b) attach free nucleotides to the growing chain.
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c) remove bases that might have been inserted incorrectly.
d) seal new short stretches of nucleotides into one continuous strand .
e) fragment old DNA that is no longer of use to the cell.
171. DNA polymerase
a) is an enzyme.
b) adds new nucleotides to a strand.
c) proofreads DNA strands to see that they are correct.
d) derives energy from A TP for synthesis of DNA strands.
e) all of the above
172. Proteins associated with DNA in eukaryotes are called
a) repressors.
b) tryptophans.
c) histones.
d) nucleosomes.
e) operons.
173. Histone-DNA units are called
a) polysomes.
b) ribosomes.
c) nucleosomes.
d) chromocenters.
e) vesicles.
174. The DNA molecule is associated with histone to form
a) looped domains.
b) scattered introns.
c) hairpin loops.
d) tightly coiled complexes.
e) lamp brushes.
175. The difference between normal hemoglobin and sickle-cell hemoglobin is in the
a) heme portion of the molecules.
b) number of chains of amino acids.
c) substitution of a specific amino acid for another specific amino acid.
d) substitution of any amino acid for a specific amino acid in the hemoglobin molecule.
e) loss of only one amino acid from the normal hemoglobin molecule.
176. Which of the following methods of calculating probability is used if the order of a specific
number of events occurring in the total is not important?
a) chi square test
b) binomial expansion
c) product rule
d) sum rule
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177.
Hydrophobic and ionic interactions between the R groups of amino acids occurs
at the __ level of protein structure.
a) primary
b) secondary
c) tertiary
d) quaternary
178.
The anticodon is located on the --a) ribosome
b) mRNA
c) tRNA
d) rRNA
179.
The molecule that attaches the amino acid to the tRNA is called --a) peptidyltransferase
b) release factor
c) aminoacyl-tRNA transferase
d) polysome
180.
Simultaneous transcription and translation occurs in ___ organisms.
a) prokaryotic
b) eukaryotic
c) both a and b
d) none of the above
181.
Translocation of the ribosome occurs during ____
a) elongation
b) termination
c) initiation
d) transcription
182.
Which of the following is not a stop codon in most species?
a) UAA
b) AUG
c) UGA
d) UAG
183.
Which of the following is true regarding the genetic code?
a) It is universal.
b) It is degenerate.
c) It allows wobble in the third base.
d) All of the above are correct.
184.
The decoding function of translation occurs during ___
a) initiation
b) elongation
c) translocation
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d) cotranslational sorting
185.
In which of the following ribosomal site receives the polypeptide chain during the
peptidyl transfer reaction?
a) A site
b) P site
c) E site
d) K site
186.
Which of the following types of mutations changes a normal codon to a stop
codon?
a) silent mutation
b) frameshift mutation
c) nonsense mutation
d) missense mutation
e) none of the above
187.
A __ mutation returns a variant to the wild type condition.
a) forward
b) reverse
c) lateral
d) vertical
e) none of the above
188.
A mutation that influences the phenotype only under specific environmental
conditions is called a ____ mutation
a) conditional
b) silent
c) transitional
d) missense
189.
cDNA is made using an enzyme called ____
a) dideoxyribonucleotide
b) integrase
c) reverse transcriptase
d) restriction endonuclease
190.
Three of the four answers listed below are steps in translation. Select the
exception.
a) initiation
b) replication
c) chain elongation
d) termination
191.
When cells are not responding to normal controls over growth and division, they
form a tissue mass known as a
a) metastasis.
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b) malignancy.
c) tumor.
d) carcinogen.
e) puff.
192.
Unusual growth of cells that do not pose a threat to surrounding tissues are
termed
a) malignant.
b) benign.
c) metastatic.
d) carcinogenic.
e) repressed.
193.
The myc gene
a) can be translocated from chromosome 8 to chromosome 14.
b) can lead to Burkitt's lymphoma.
c) does not cause cancer until it is moved.
d) both a and b, but not c
e) a, b, and c
194.
Which of the following statements concerning cancer cells is most accurate?
a) Oncogenes are part of the regulatory section of a chromosome.
b) Tumor cells have lost their inhibition to stop dividing.
c) Oncogenes help control runaway cell division.
d) Benign tumors usually spread to other body parts.
e) Metastasis is the spread of benign tumors.
195.
The nature of development is based upon
a) which genes are active in a given cell.
b) when the genes function.
c) what gene products appear.
d) the amount of cellular products generated.
e) all of the above
196.
Which of the following statements is false?
a) All the cells of anyone single individual human have the same genes.
b) Only red blood cells have hemoglobin genes.
c) Different genes are activated depending on the cell they are in.
d) Genetically, liver cells and brain cells differ mostly in function.
e) Cells don't express all of their genes all of the time.
197.
Genes located in different regions of the body during embryonic development may
a) be turned on and off.
b) never be turned on.
c) be turned on and left on.
d) be activated for only a short time in one cell and a long time in another cell.
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e) all of the above
198.
A mammalian female
a) usually has one Barr body.
b) is a mosaic for the X-linked traits she inherits.
c) uses the paternal X chromosome for a Barr body.
d) uses the maternal X chromosome for a Barr body.
e) always a and b
199.
Lyonization of a cat refers to
a) hybridization.
b) sterilization.
c) mosaic phenotype.
d) inactivation of one of the X chromosomes.
e) both c and d
200.
The mosaic effect in human females can be observed in
a) skin color.
b) hair color.
c) distribution of fat cells.
d) distribution of sweat glands.
e) all of the above
DR. KOFI OWUSU-DAAKU
TUESDAY SEPTEMBER 17, 2013
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Compiled by: OPOKU EMMANUEL
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