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Campbell Biology, 10e (Reece)
Chapter 13 Meiosis
and Sexual Life Cycles
1)
If a horticulturist breeding gardenias succeeds in having a single plant with a
particularly desirable set of traits, which of the following would be her most
probable and efficient route to establishing a line of such plants?
A)
Backtrack through her previous experiments to obtain another plant with the
same traits.
B)
Breed this plant with another plant with much weaker traits.
C)
Clone the plant.
D)
Force the plant to self-pollinate to obtain an identical one.
2)
Which of the following defines a genome?
A)
the complete set of an organism's polypeptides
B)
the complete set of a species' polypeptides
C)
a karyotype
D)
the complete set of an organism's genes and other DNA sequences
3)
Asexual reproduction occurs during _____.
A)
meiosis
B)
mitosis
C)
fertilization
D)
chromosome exchange between organisms of different species
4)
Quaking aspen can send out underground stems for asexual reproduction. Sexual
reproduction is not as common, but when it does happen, the haploid gametes
have 19 chromosomes. How many chromosomes are in the cells of the underground
stems?
A)
9
B)
10
C)
19
D)
38
5)
Which of the following is a true statement about sexual vs. asexual reproduction?
A)
Asexual reproduction, but not sexual reproduction, is characteristic of plants
and fungi.
B)
In sexual reproduction, individuals transmit half of their nuclear genes to
each of their offspring.
C)
In asexual reproduction, offspring are produced by fertilization without
meiosis.
D)
Asexual reproduction produces only haploid offspring.
6)
At which stage of mitosis are chromosomes usually photographed in the
preparation of a karyotype?
A)
prophase
B)
metaphase
C)
anaphase
D)
interphase
7)
Which of the following is true of a species that has a chromosome number of 2n
= 16?
A)
The species is diploid with 32 chromosomes per cell.
B)
The species has 16 sets of chromosomes per cell.
C)
Each diploid cell has eight homologous pairs.
D)
A gamete from this species has four chromosomes.
8)
Eukaryotic sexual life cycles show tremendous variation. Of the following
elements, which do all sexual life cycles have in common?
I. Alternation
of generations
II. Meiosis
III. Fertilization
IV. Gametes
V. Spores
A)
I, II, and IV
B)
II, III, and IV
C)
II, IV, and V
D)
I, II, III, IV, and V
9)
In a plant's sexual life cycle _____.
A)
sporophytes produce gametes by meiosis
B)
gametophytes produce gametes by mitosis
C)
gametophytes produce gametes by meiosis
D)
sporophytes produce gametes by mitosis
10)
Which of the following is an example of alternation of generations?
A)
A grandparent and grandchild each have dark hair, but the parent has blond
hair.
B)
A diploid plant (sporophyte) produces, by meiosis, a spore that gives rise to a
multicellular, haploid pollen grain (gametophyte).
C)
A diploid animal produces gametes by meiosis, and the gametes undergo
fertilization to produce a diploid zygote.
D)
A haploid mushroom produces gametes by mitosis, and the gametes undergo
fertilization, which is immediately followed by meiosis.
11)
A given organism has 46 chromosomes in its karyotype. Therefore, we can
conclude that it must _____.
A)
be human
B)
be an animal
C)
reproduce sexually
D)
have gametes with 23 chromosomes
12)
A triploid cell contains sets of three homologous chromosomes. If a cell of a
usually diploid species with 42 chromosomes per cell is triploid, this cell
would be expected to have which of the following?
A)
63 chromosomes in 
pairs
pairs
B)
63 chromosomes in 21 sets of 3
C)
63 chromosomes, each with three chromatids
D)
21 chromosome pairs and 21 unique chromosomes
13)
Which of the following might result in a human zygote with 45 chromosomes?
A)
an error in either egg or sperm meiotic anaphase
B)
failure of the egg nucleus to be fertilized by the sperm
C)
failure of an egg to complete meiosis II
D)
incomplete cytokinesis during spermatogenesis after meiosis I
14)
In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of
these pairs, such as pair 14, which of the following do the two chromosomes of
the pair have in common?
A)
length and position of the centromere only
B)
length, centromere position, and staining pattern only
C)
length, centromere position, staining pattern, and traits coded for by their
genes
D)
They have nothing in common except that they are X-shaped.
Refer
to the life cycles illustrated in the figure below to answer the following
question(s).
15)
Which of the life cycles is typical for animals?
A)
I only
B)
II only
C)
III only
D)
I and III
16)
Which of the life cycles is typical for plants and some algae?
A)
I only
B)
II only
C)
III only
D)
I and III
17)
Which of the life cycles is typical for most fungi and some protists?
A)
I only
B)
II only
C)
III only
D)
I and II
18)
In a life cycle such as that shown in part III of the figure above, if the
zygote's chromosome number is 10, which of the following will be true?
A)
The sporophyte's chromosome number per cell is 10 and the gametophyte's is 5.
B)
The sporophyte's chromosome number per cell is 5 and the gametophyte's is 10.
C)
The sporophyte and gametophyte each have 10 chromosomes per cell.
D)
The sporophyte and gametophyte each have 5 chromosomes per cell.
19)
Homologous chromosomes _____.
A)
are identical
B)
carry information for the same traits
C)
carry the same alleles
D)
align on the metaphase plate in meiosis II
20)
If meiosis produces haploid cells, how is the diploid number restored for those
organisms that spend most of their life cycle in the diploid state?
A)
DNA replication
B)
reverse transcription
C)
synapsis
D)
fertilization
21)
The human X and Y chromosomes _____.
A)
are both present in every somatic cell of males and females
B)
are the same size and have the same number of genes
C)
include genes that determine an individual's sex
D)
are called autosomes
22)
Which of these is a karyotype?
A)
a display of all of the cell types in an organism
B)
organized images of a cell’s chromosomes
C)
the appearance of an organism
D)
a display of a cell’s mitotic stages
23)
If a cell has completed meiosis I and is just beginning meiosis II, which of
the following is an appropriate description of its contents?
A)
It has half the amount of DNA as the cell that began meiosis.
B)
It has half the chromosomes but twice the DNA of the originating cell.
C)
It has one-fourth the DNA and one-half the chromosomes as the originating cell.
D)
It is identical in content to another cell formed from the same meiosis I
event.
24)
The somatic cells of a privet shrub each contain 46 chromosomes. How do privet
chromosomes differ from the chromosomes of humans ,who also have 46?
A)
Privet cells cannot reproduce sexually.
B)
Privet sex cells have chromosomes that can synapse with human chromosomes in
the laboratory.
C)
Genes of privet chromosomes are significantly different than those in humans.
D)
Privet shrubs must be metabolically more like animals than like other shrubs.
25)
After telophase I of meiosis, the chromosomal makeup of each daughter cell is
_____.
A)
diploid, and the chromosomes are each composed of a single chromatid
B)
diploid, and the chromosomes are each composed of two chromatids
C)
haploid, and the chromosomes are each composed of a single chromatid
D)
haploid, and the chromosomes are each composed of two chromatids
26)
How do cells at the completion of meiosis compare with cells that are in
prophase of meiosis I? They have _____.
A)
half the number of chromosomes and half the amount of DNA.
B)
the same number of chromosomes and half the amount of DNA.
C)
half the number of chromosomes and one-fourth the amount of DNA.
D)
half the amount of cytoplasm and twice the amount of DNA.
27)
Which of the following happens at the conclusion of meiosis I?
A)
Homologous chromosomes of a pair are separated from each other.
B)
The chromosome number per cell remains the same.
C)
Sister chromatids are separated.
D)
Four daughter cells are formed.
28)
Sister chromatids separate from each other during _____.
A)
meiosis I only
B)
meiosis II only
C)
mitosis and meiosis I
D)
mitosis and meiosis II
29)
Which of the following occurs in meiosis but not in mitosis?
A)
chromosome replication
B)
synapsis of chromosomes
C)
alignment of chromosomes at the equator
D)
condensation of chromosomes
30)
When we first see chiasmata under a microscope, we know that _____.
A)
meiosis II has occurred
B)
anaphase II has occurred
C)
prophase I is occurring
D)
separation of homologs has occurred
For
the following questions, match the key event of meiosis with the stages listed
below.
I. Prophase
I V. Prophase II
II. Metaphase
I VI. Metaphase II
III. Anaphase
I VII. Anaphase II
IV. Telophase
I VIII. Telophase II
31)
Homologous chromosomes are aligned at the equator of the spindle.
A)
I
B)
II
C)
IV
D)
VI
32)
Centromeres of sister chromatids disjoin and chromatids separate.
A)
III
B)
IV
C)
V
D)
VII
Refer
to the drawings in the figure below of a single pair of homologous chromosomes
as they might appear during various stages of either mitosis or meiosis, and
answer the following questions.
33)
Which diagram represents anaphase I of meiosis?
A)
I
B)
II
C)
IV
D)
V
34)
Which diagram represents anaphase II of meiosis?
A)
I
B)
III
C)
IV
D)
V
You
have isolated DNA from three different cell types of the same organism,
determined the relative DNA content for each type, and plotted the results on
the graph shown in the figure below. Refer to the graph to answer the following
question(s).
35)
Which sample of DNA might be from a nerve cell arrested in G0 of the cell cycle?
A)
I
B)
II
C)
III
D)
either I or II
36)
Which sample might represent an animal cell in the G2 phase of the cell cycle?
A)
I
B)
II
C)
III
D)
both I and II
37)
Which sample might represent a zygote?
A)
I
B)
II
C)
III
D)
either I or II
Refer
to the information and figure below to answer the following question(s).
A
certain (hypothetical) organism is diploid, has either blue or orange wings as
the consequence of one of its genes on chromosome 12, and has either long or
short antennae as the result of a second gene on chromosome 19, as shown in the
figure.
38)
A certain female's number 12 chromosomes both have the blue gene and number 19
chromosomes both have the long gene. As cells in her ovaries undergo meiosis,
her resulting eggs (ova) may have which of the following?
A)
either two number 12 chromosomes with blue genes or two with orange genes
B)
either two number 19 chromosomes with long genes or two with short genes
C)
either one blue or one orange gene in addition to either one long or one short
gene
D)
one chromosome 12 with one blue gene and one chromosome 19 with one long gene
39)
If a female of this species has one chromosome 12 with a blue gene and another
chromosome 12 with an orange gene, and has both number 19 chromosomes with
short genes, she will produce which of the following egg types?
A)
only blue short gene eggs
B)
only orange short gene eggs
C)
one-half blue short and one-half orange short gene eggs
D)
three-fourths blue short and one-fourth orange short gene eggs
40)
A female with a paternal set of one orange and one long gene chromosome and a
maternal set comprised of one blue and one short gene chromosome is expected to
produce which of the following types of eggs after meiosis?
A)
All eggs will have maternal types of gene combinations.
B)
All eggs will have paternal types of gene combinations.
C)
Half the eggs will have maternal and half will have paternal combinations.
D)
Each egg has a one-fourth chance of having either blue long, blue short, orange
long, or orange short combinations.
41)
Somatic cells of roundworms have four individual chromosomes per cell. How many
chromosomes would you expect to find in an ovum from a roundworm?
A)
four
B)
two
C)
eight
D)
a diploid number
42)
Which of the following can occur by the process of meiosis but not mitosis?
A)
Haploid cells fuse to form diploid cells.
B)
Haploid cells multiply into more haploid cells.
C)
Diploid cells form haploid cells.
D)
A diploid cell combines with a haploid cell.
43)
In meiosis, homologous chromosomes are separated during _____.
A)
anaphase II
B)
prophase I
C)
mitosis
D)
anaphase I
44)
What is a major difference between meiosis II and mitosis in a diploid animal?
A)
Homologues align on the metaphase plate in meiosis II.
B)
Sister chromatids separate in mitosis, and homologues separate in meiosis II.
C)
Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.
D)
Crossover takes place in meiosis II.
45)
What is a major difference between mitosis and meiosis I in a diploid organism?
A)
Sister chromatids separate in mitosis, while homologous pairs of chromosomes
separate in meiosis I.
B)
Sister chromatids separate in mitosis, while homologous pairs of chromosomes
separate in meiosis II.
C)
DNA replication takes place prior to mitosis, but not before meiosis I.
D)
Only meiosis I results in daughter cells that contain identical genetic
information.
46)
Crossing over normally takes place during which of the following processes?
A)
meiosis II
B)
meiosis I
C)
mitosis
D)
mitosis and meiosis II
47)
For the duration of meiosis I, each chromosome _____.
A)
is paired with a homologous chromosome
B)
consists of two sister chromatids joined by a centromere
C)
consists of a single strand of DNA
D)
is joined with its homologous pair to form a synaptonemal complex
48)
Homologous pairs of chromosomes align opposite of each other at the equator of
a cell during _____.
A)
mitosis metaphase
B)
meiosis metaphase I
C)
meiosis telophase II
D)
meiosis metaphase II
49)
Centromeres split and sister chromatids migrate to opposite poles in meiosis
_____.
A)
anaphase I
B)
telophase I
C)
anaphase II
D)
telophase II
50)
Quaking aspen can send out underground stems for asexual reproduction. Sexual
reproduction is not as common, but when it does happen, the haploid gametes
have 19 chromosomes. How many chromosomes are in the cells of the underground
stems?
A)
9
B)
10
C)
19
D)
38
51)
Independent assortment of chromosomes occurs during _____.
A)
meiosis I only
B)
meiosis II only
C)
mitosis and meiosis I
D)
mitosis and meiosis II
52)
For a species with a haploid number of 23 chromosomes, how many different
combinations of maternal and paternal chromosomes are possible for the gametes?
A)
23
B)
46
C)
about 1000
D)
about 8 million
53)
Independent assortment of chromosomes is a result of _____.
A)
the random way each pair of homologous chromosomes lines up at the metaphase
plate during meiosis I
B)
the random combinations of eggs and sperm during fertilization
C)
the random distribution of the sister chromatids to the two daughter cells
during anaphase II
D)
the diverse combination of alleles that may be found within any given
chromosome
54)
When homologous chromosomes cross over, what occurs?
A)
Two chromatids get tangled, resulting in one re-sequencing its DNA.
B)
Two sister chromatids exchange identical pieces of DNA.
C)
Corresponding segments of non-sister chromatids are exchanged.
D)
Maternal alleles are "corrected" to be like paternal alleles and vice
versa.
55)
How is natural selection related to sexual reproduction as opposed to asexual
reproduction?
A)
Sexual reproduction results in many new gene combinations, some of which will
lead to differential reproduction.
B)
Sexual reproduction results in the greatest number of new mutations.
C)
Sexual reproduction allows the greatest number of offspring to be produced.
D)
Sexual reproduction utilizes far less energy than asexual reproduction.
56)
The diploid number of a roundworm species is 4. Assuming there is no crossover,
and random segregation of homologues during meiosis, how many different
possible combinations of chromosomes might there be in the offspring (not
including variety generated by crossing over)?
A)
4
B)
8
C)
16
D)
64
57)
The bulldog ant has a diploid number of two chromosomes. Therefore, following
meiosis, each daughter cell will have a single chromosome. Diversity in this
species may be generated by mutations and _____.
A)
crossing over
B)
independent assortment
C)
crossing over and independent assortment
D)
nothing else
58)
The fastest way for organisms to adapt to a changing environment involves
_____.
A)
mutation
B)
asexual reproduction
C)
sexual reproduction
59)
Imagine that there are twenty-five different species of protists living in a
tide pool. Some of these species reproduce both sexually and asexually, and
some of them can reproduce only asexually. The pool gradually becomes infested
with disease-causing viruses and bacteria. Which species are more likely to
thrive in the changing environment?
A)
the sexually reproducing species
B)
the asexually reproducing species
C)
Sexually and asexually reproducing species are equally likely to thrive.
60)
In eukaryotes, genetic information is passed to the next generation by
processes that include mitosis or meiosis. Which of the explanations identifies
the correct process and supports the claim that heritable information is passed
from one generation to another?
A)
During mitosis, DNA replication occurs twice within the cell cycle to insure a
full set of chromosomes within each of the daughter cells produced.
B)
Mitosis, followed by cytokinesis, produces daughter cells that are genetically
different from the parent cell, thus insuring variation within the population.
C)
In asexual reproduction, a single individual is the sole parent and passes
copies of its genes to its offspring without the fusion of gametes.
D)
Single-celled organisms can fuse their cells, reproducing asexually through
mitosis to form new cells that are not identical to the parent cell.
61)
Genetic variation leads to genetic diversity in populations and is the raw
material for evolution. Biological systems have multiple processes, such as
reproduction, that affect genetic variation. They are evolutionarily conserved
and shared by various organisms.
Which
statement best represents the connection between reproduction and evolution?
A)
Plants that use sexual reproduction are rare since this type of reproduction in
plants does not contribute to genetic diversity.
B)
In order to increase genetic diversity for evolution in sexually reproducing
organisms, mutations must occur in the zygote after fertilization.
C)
Since prokaryotic organisms reproduce asexually, there is no mechanism for them
to add genetic diversity for evolution.
D)
Sexual reproduction increases genetic variation because random mutations can be
shuffled between organisms.
Campbell Biology, 10e (Reece)
Chapter 14 Mendel
and the Gene Idea
1)
What do we mean when we use the terms monohybrid cross and dihybrid
cross?
A)
A monohybrid cross involves a single parent, whereas a dihybrid cross involves
two parents.
B)
A dihybrid cross involves organisms that are heterozygous for two characters
that are being studied, and a monohybrid cross involves organisms that are
heterozygous for only one character being studied.
C)
A monohybrid cross is performed for one generation, whereas a dihybrid cross is
performed for two generations.
D)
A monohybrid cross results in a 9:3:3:1 ratio whereas a dihybrid cross gives a
3:1 ratio.
2)
What was the most significant conclusion that Gregor Mendel drew from his
experiments with pea plants?
A)
There is considerable genetic variation in garden peas.
B)
Traits are inherited in discrete units and are not the results of
"blending."
C)
Recessive genes occur more frequently in the F1 generation than do dominant ones.
D)
Genes are composed of DNA.
3)
How many unique gametes could be produced through independent assortment by an
individual with the genotype AaBbCCDdEE?
A)
4
B)
8
C)
16
D)
64
4)
The individual with genotype AaBbCCDdEE can make many kinds of gametes.
Which of the following is the major reason?
A)
recurrent mutations forming new alleles
B)
crossing over during prophase I
C)
different possible assortment of chromosomes into gametes
D)
the tendency for dominant alleles to segregate together
5)
Mendel continued some of his experiments into the F2 or F3 generation to _____.
A)
obtain a larger number of offspring on which to base statistics
B)
observe whether or not a recessive trait would reappear
C)
observe whether or not the dominant trait would reappear
D)
distinguish which alleles were segregating
6)
Which of the following statements about independent assortment and segregation
is correct?
A)
The law of independent assortment requires describing two or more genes
relative to one another.
B)
The law of segregation requires describing two or more genes relative to one
another.
C)
The law of independent assortment is accounted for by observations of prophase
I.
D)
The law of segregation is accounted for by anaphase of mitosis.
7)
A sexually reproducing animal has two unlinked genes, one for head shape (H)
and one for tail length (T). Its genotype is HhTt. Which of the
following genotypes is possible in a gamete from this organism?
A)
Hh
B)
HhTt
C)
T
D)
HT
8)
Mendel accounted for the observation that traits that had disappeared in the F1 generation reappeared in the F2 generation by proposing that _____.
A)
new mutations were frequently generated in the F2 progeny, "reinventing" traits that
had been lost in the F1
B)
the mechanism controlling the appearance of traits was different between the F1 and the F2 plants
C)
traits can be dominant or recessive, and the recessive traits were obscured by
the dominant ones in the F1
D)
members of the F1 generation had only one allele for each trait,
but members of the F2 had two alleles for each
trait
9)
The fact that all seven of the pea plant traits studied by Mendel obeyed the
principle of independent assortment most probably indicates which of the
following?
A)
None of the traits obeyed the law of segregation.
B)
The diploid number of chromosomes in the pea plants was 7.
C)
All of the genes controlling the traits were located on the same chromosome.
D)
All of the genes controlling the traits behaved as if they were on different
chromosomes.
10)
Mendel's observation of the segregation of alleles in gamete formation has its
basis in which of the following phases of cell division?
A)
prophase I of meiosis
B)
anaphase II of meiosis
C)
metaphase II of meiosis
D)
anaphase I of meiosis
11)
Mendel's second law of independent assortment has its basis in which of the
following events of meiosis I?
A)
synapsis of homologous chromosomes
B)
crossing over
C)
alignment of tetrads at the equator
D)
separation of cells at telophase
Use
the figure and the following description to answer the question(s) below.
In
a particular plant, leaf color is controlled by gene locus D. Plants
with at least one allele D have dark green leaves, and plants with the
homozygous recessive dd genotype have light green leaves. A
true-breeding, dark-leaved plant is crossed with a light-leaved one, and the F1 offspring is allowed to self-pollinate. The
predicted outcome of the F2 is diagrammed in the
Punnett square shown in the figure, where 1, 2, 3, and 4 represent the
genotypes corresponding to each box within the square.
12)
Which of the boxes marked 1-4 correspond to plants with dark leaves?
A)
1 only
B)
2 and 3
C)
4 only
D)
1, 2, and 3
13)
Which of the boxes marked 1-4 correspond to plants with a heterozygous
genotype?
A)
1
B)
1, 2, and 3
C)
2 and 3
D)
2, 3, and 4
14)
Which of the boxes marked 1-4 correspond to plants that will be true-breeding?
A)
1 and 4 only
B)
2 and 3 only
C)
1, 2, 3, and 4
D)
1 only
15)
Skin color in a certain species of fish is inherited via a single gene with
four different alleles. How many different types of gametes would be possible
in this system?
A)
2
B)
4
C)
8
D)
16
16)
Why did the F1 offspring of Mendel's classic pea cross always
look like one of the two parental varieties?
A)
No genes interacted to produce the parental phenotype.
B)
Each allele affected phenotypic expression.
C)
The traits blended together during fertilization.
D)
One allele was dominant.
17)
Mendel crossed yellow-seeded and green-seeded pea plants and then allowed the
offspring to self-pollinate to produce an F2 generation. The results were as follows: 6022
yellow and 2001 green (8023 total). The allele for green seeds has what
relationship to the allele for yellow seeds?
A)
dominant
B)
incomplete dominant
C)
recessive
D)
codominant
18)
Albinism is an autosomal (not sex-linked) recessive trait. A man and woman are
both of normal pigmentation, but both have one parent who is albino (without
melanin pigmentation). What is the probability that their first child will be
an albino?
A)
0
B)
1/2
C)
1/4
D)
1
19)
Albinism is an autosomal (not sex-linked) recessive trait. A man and woman are
both of normal pigmentation and have one child out of three who is albino
(without melanin pigmentation). What are the genotypes of the albino's parents?
A)
One parent must be homozygous for the recessive allele; the other parent can be
homozygous dominant, homozygous recessive, or heterozygous.
B)
One parent must be heterozygous; the other parent can be homozygous dominant,
homozygous recessive, or heterozygous.
C)
Both parents must be heterozygous.
D)
One parent must be homozygous dominant; the other parent must be heterozygous.
20)
A black guinea pig crossed with an albino guinea pig produced twelve black
offspring. When the albino was crossed with a second black animal, six blacks
and six albinos were obtained. What is the best explanation for this genetic
situation?
A)
Albino is recessive; black is dominant.
B)
Albino is dominant; black is incompletely dominant.
C)
Albino and black are codominant.
D)
Albino is recessive; black is codominant.
21)
Gray seed color in peas is dominant to white. Assume that Mendel conducted a
series of experiments where plants with gray seeds were crossed among
themselves, and the following progeny were produced: 302 gray and 98 white.
(a)
What is the most probable genotype of each parent?
(b)
Based on your answer in (a) above, what genotypic and phenotypic ratios are
expected in these progeny? (Assume the following symbols: G = gray and g
= white.)
A)
(a) GG × gg; (b) genotypic = 3:1, phenotypic = 1:2:1
B)
(a) Gg × Gg; (b) genotypic = 1:2:1, phenotypic = 3:1
C)
(a) GG × Gg; (b) genotypic = 1:2:1, phenotypic = 2:1
D)
(a) gg × Gg; (b) genotypic = 1:2, phenotypic = 3:1
22)
When Mendel crossed yellow-seeded and green-seeded pea plants, all the
offspring were yellow seeded. When he took these F1 yellow-seeded plants and crossed them to
green-seeded plants, what genotypic ratio was expected?
A)
1:2:1
B)
3:1
C)
1:1
D)
1:1:1:1
23)
Black fur in mice (B) is dominant to brown fur (b). Short tails (T)
are dominant to long tails (t). What fraction of the progeny of crosses BbTt
× BBtt will be expected to have black fur and long tails?
A)
1/16
B)
3/8
C)
1/2
D)
9/16
24)
In certain plants, tall is dominant to short. If a heterozygous plant is
crossed with a homozygous tall plant, what is the probability that the
offspring will be short?
A)
1
B)
1/2
C)
1/4
D)
0
25)
In the cross AaBbCc × AaBbCc, what is the probability of
producing the genotype AABBCC?
A)
1/4
B)
1/8
C)
1/16
D)
1/64
26)
Given the parents AABBCc × AabbCc, assume simple dominance for
each trait and independent assortment. What proportion of the progeny will be
expected to phenotypically resemble the first parent with genotype AABBCc?
A)
1/4
B)
3/4
C)
3/8
D)
1
27)
Which of the following is the best statement of the use of the addition rule of
probability?
A)
the probability that two or more independent events will both occur
B)
the probability that either one of two independent events will occur
C)
the probability of producing two or more heterozygous offspring
D)
the likelihood that a trait is due to two or more meiotic events
28)
Which of the following calculations require that you utilize the addition rule?
A)
Calculate the probability of black offspring from the cross AaBb × AaBb,
where B is the symbol for black.
B)
Calculate the probability of children with both cystic fibrosis and polydactyly
when parents are each heterozygous for both genes.
C)
Calculate the probability of each of four children having cystic fibrosis if
the parents are both heterozygous.
D)
Calculate the probability of a child having either sickle-cell anemia or cystic
fibrosis if parents are each heterozygous for both.
29)
Two true-breeding stocks of pea plants are crossed. One parent has red, axial
flowers and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes
for flower color and location assort independently. Among the F2 offspring, what is the probability of plants
with white axial flowers?
A)
9/16
B)
1/16
C)
3/16
D)
1/4
30)
A man has extra digits (six fingers on each hand and six toes on each foot).
His wife and their daughter have a normal number of digits. Having extra digits
is a dominant trait. The couple's second child has extra digits. What is the
probability that their next (third) child will have extra digits?
A)
1/2
B)
1/16
C)
1/8
D)
3/4
31)
Phenylketonuria is an inherited disease caused by a recessive autosomal allele.
If a woman and her husband are both carriers, what is the probability that
their first child will be a phenotypically normal girl?
A)
1/4
B)
1/16
C)
3/16
D)
3/8
32)
Assuming independent assortment for all gene pairs, what is the probability
that the following parents, AABbCc × AaBbCc, will produce an AaBbCc
offspring?
A)
1/2
B)
1/16
C)
1/8
D)
3/4
33)
Suppose two AaBbCc individuals are mated. Assuming that the genes are
not linked, what fraction of the offspring are expected to be homozygous
recessive for the three traits?
A)
1/4
B)
1/8
C)
1/16
D)
1/64
34)
In cattle, roan coat color (mixed red and white hairs) occurs in the
heterozygous (Rr) offspring of red (RR) and white (rr)
homozygotes. Which of the following crosses would produce offspring in the
ratio of 1 red:2 roan:1 white?
A)
red × white
B)
roan × roan
C)
white × roan
D)
red × roan
35)
Which of the following describes the ability of a single allele to have
multiple phenotypic effects?
A)
incomplete dominance
B)
multiple alleles
C)
pleiotropy
D)
epistasis
36)
Which of the following is an example of polygenic inheritance?
A)
pink flowers in snapdragons
B)
the ABO blood group in humans
C)
white and purple flower color in peas
D)
skin pigmentation in humans
37)
Hydrangea plants of the same genotype are planted in a large flower garden.
Some of the plants produce blue flowers and others pink flowers. This can be
best explained by which of the following?
A)
the knowledge that multiple alleles are involved
B)
the allele for blue hydrangea being completely dominant
C)
the alleles being codominant
D)
environmental factors such as soil pH
38)
Which of the following provides an example of epistasis?
A)
Recessive genotypes for each of two genes (aabb) results in an albino
corn snake.
B)
In rabbits and many other mammals, one genotype (ee) prevents any fur
color from developing.
C)
In Drosophila (fruit flies), white eyes can be due to an X-linked gene
or to a combination of other genes.
D)
In cacti, there are several genes for the type of spines.
39)
Radish flowers may be red, purple, or white. A cross between a red-flowered
plant and a white-flowered plant yields all-purple offspring. The part of the
radish we eat may be oval or long, with long being the dominant trait. If
true-breeding red long radishes are crossed with true-breeding white oval
radishes, the F1 will be expected to be which of the following?
A)
red and long
B)
white and long
C)
purple and long
D)
purple and oval
40)
Radish flowers may be red, purple, or white. A cross between a red-flowered
plant and a white-flowered plant yields all-purple offspring. The flower color
trait in radishes is an example of which of the following?
A)
a multiple allelic system
B)
sex linkage
C)
codominance
D)
incomplete dominance
41)
Skin color in a certain species of fish is inherited via a single gene with four
different alleles. One fish of this type has alleles 1 and 3 (S1S3) and its
mate has alleles 2 and 4 (S2S4). If each allele confers a unit of
color darkness such that S1 has one unit, S2 has two units, and so on, then what proportion
of their offspring would be expected to have five units of color?
A)
1/4
B)
1/8
C)
1/2
D)
0
42)
Gene S controls the sharpness of spines in a type of cactus. Cactuses
with the dominant allele, S, have sharp spines, whereas homozygous
recessive ss cactuses have dull spines. At the same time, a second gene,
N, determines whether or not cactuses have spines. Homozygous recessive nn
cactuses have no spines at all. The relationship between genes S and N
is an example of _____.
A)
incomplete dominance
B)
epistasis
C)
pleiotropy
D)
codominance
43)
Gene S controls the sharpness of spines in a type of cactus. Cactuses
with the dominant allele, S, have sharp spines, whereas homozygous
recessive ss cactuses have dull spines. At the same time, a second gene,
N, determines whether or not cactuses have spines. Homozygous recessive nn
cactuses have no spines at all. A cross between a true-breeding sharp-spined
cactus and a spineless cactus would produce_____.
A)
all sharp-spined progeny
B)
50% sharp-spined, 50% dull-spined progeny
C)
25% sharp-spined, 50% dull-spined, 25% spineless progeny
D)
It is impossible to determine the phenotypes of the progeny.
44)
Gene S controls the sharpness of spines in a type of cactus. Cactuses
with the dominant allele, S, have sharp spines, whereas homozygous
recessive ss cactuses have dull spines. At the same time, a second gene,
N, determines whether or not cactuses have spines. Homozygous recessive nn
cactuses have no spines at all. If doubly heterozygous SsNn cactuses
were allowed to self-pollinate, the F2 would
segregate in which of the following ratios?
A)
3 sharp-spined:1 spineless
B)
1 sharp-spined:2 dull-spined:1 spineless
C)
1 sharp-spined:1 dull-spined:1 spineless
D)
9 sharp-spined:3 dull-spined:4 spineless
45)
Feather color in budgies is determined by two different genes, Y and B,
one for pigment on the outside and one for the inside of the feather. YYBB,
YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb
or Yybb is yellow; and yybb is white. A blue budgie is crossed
with a white budgie. Which of the following results is NOT possible?
A)
green offspring only
B)
yellow offspring only
C)
blue offspring only
D)
green and yellow offspring
46)
Feather color in budgies is determined by two different genes, Y and B,
one for pigment on the outside and one for the inside of the feather. YYBB,
YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb
or Yybb is yellow; and yybb is white. Two blue budgies were
crossed. Over the years, they produced twenty-two offspring, five of which were
white. What are the most likely genotypes for the two blue budgies?
A)
yyBB and yyBB
B)
yyBB and yyBb
C)
yyBb and yyBb
D)
yyBb and yybb
47)
A woman who has blood type A positive has a daughter who is type O positive and
a son who is type B negative. Rh positive is a trait that shows simple
dominance over Rh negative. Which of the following is a possible phenotype for
the father?
A)
A negative
B)
O negative
C)
B positive
D)
AB negative
48)
A gene for the MN blood group has codominant alleles M and N. If
both children are of blood type M, which of the following is possible?
A)
Each parent is either M or MN.
B)
Each parent must be type M.
C)
Both children are heterozygous for this gene.
D)
Neither parent can have the N allele.
49)
Marfan syndrome in humans is caused by an abnormality of the connective tissue
protein fibrillin. Patients are usually very tall and thin, with long spindly
fingers, curvature of the spine, sometimes weakened arterial walls, and
sometimes ocular problems, such as lens dislocation. Which of the following
would you conclude about Marfan syndrome from this information?
A)
It is recessive.
B)
It is dominant.
C)
It is pleiotropic.
D)
It is epistatic.
50)
In rabbits, the homozygous CC is normal, Cc results in deformed
legs, and cc results in very short legs. The genotype BB produces
black fur, Bb brown fur, and bb white fur. If a cross is made
between brown rabbits with deformed legs and white rabbits with deformed legs,
what percentage of the offspring would be expected to have deformed legs and
white fur?
A)
25%
B)
33%
C)
100%
D)
50%
51)
In humans, ABO blood types refer to glycoproteins in the membranes of red blood
cells. There are three alleles for this autosomal gene: IA, IB,
and i. The IA allele codes for the A glycoprotein, The IB
allele codes for the B glycoprotein, and the i allele doesn't code for
any membrane glycoprotein. IA and IB are codominant, and i
is recessive to both IA and IB. People with type A blood have the
genotypes IAIA or IAi, people with type B blood are IBIB
or IBi, people with type AB blood are IAIB, and people with type
O blood are ii. If a woman with type AB blood marries a man with type O
blood, which of the following blood types could their children possibly have?
A)
A and B
B)
AB and O
C)
A, B, and O
D)
A, B, AB, and O
52)
An obstetrician knows that one of her patients is a pregnant woman whose fetus
is at risk for a serious disorder that is detectable biochemically in fetal
cells. The obstetrician would most reasonably offer which of the following
procedures to her patient?
A)
karyotyping of the woman’s somatic cells
B)
X-ray
C)
amniocentesis or CVS
D)
blood transfusion
53)
In some parts of Africa, the frequency of heterozygosity for the sickle-cell
anemia allele is unusually high, presumably because this reduces the frequency
of malaria. Such a relationship is related to which of the following?
A)
Mendel's law of independent assortment
B)
Mendel's law of segregation
C)
Darwin's explanation of natural selection
D)
the malarial parasite changing the allele
54)
Phenylketonuria (PKU) is a recessive human disorder in which an individual
cannot appropriately metabolize the amino acid phenylalanine. This amino acid
is not naturally produced by humans. Therefore, the most efficient and
effective treatment is which of the following?
A)
Feed them the substrate that can be metabolized into this amino acid.
B)
Regulate the diet of the affected persons to severely limit the uptake of the
amino acid.
C)
Feed the patients the missing enzymes in a regular cycle, such as twice per
week.
D)
Feed the patients an excess of the missing product.
55)
Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in
which there is very early senility and death, usually from coronary artery
disease, at an average age of 13 years. Patients, who look very old even as
children, do not live to reproduce. Which of the following represents the most
likely assumption?
A)
The disease is autosomal dominant.
B)
The disorder will increase in frequency in successive generations within a
family.
C)
The disorder may be due to mutation in a single protein-coding gene.
D)
Each patient will have had at least one affected grandparent or parent.
56)
One of two major forms of a human condition called neurofibromatosis (NF 1) is
inherited as a dominant gene, although it may range from mildly to very
severely expressed. Which of the following is the best explanation for why a
young, affected child is the first in her family to be diagnosed?
A)
The mother carries the gene but does not express it.
B)
One of the parents has a mild expression of the gene.
C)
The condition skipped a generation in the family.
D)
The child has one more chromosome than either of the parents.
The
following questions refer to the pedigree chart in the figure below for a
family, some of whose members exhibit the dominant trait, W. Affected
individuals are indicated by a dark square or circle.
57)
What is the genotype of individual II-5?
A)
WW
B)
Ww
C)
ww
D)
ww or Ww
58)
What is the likelihood that the progeny of IV-3 and IV-4 will have the trait?
A)
0%
B)
50%
C)
75%
D)
100%
59)
What is the probability that individual III-1 is Ww?
A)
3/4
B)
1/4
C)
2/4
D)
1
The
figure below shows the pedigree for a family. Dark-shaded symbols represent
individuals with one of the two major types of colon cancer. Numbers under the
symbols are the individual's age at the time of diagnosis. Males are
represented by squares, females by circles.
60)
From this pedigree, this trait seems to be inherited _____.
A)
from mothers
B)
as an autosomal recessive
C)
as a result of epistasis
D)
as an autosomal dominant
61)
Which of the following statements is a correct explanation for the observation
that all offspring exhibit a phenotype for a particular trait that appears to
be a blend of the two parental varieties?
A)
Neither of the parental genes is dominate over the other.
B)
The genes for the trait are dominant in both of the parents.
C)
The genes are linked and do not separate during meiosis.
D)
The genes for the trait are recessive in both of the parents.
62)
The pattern of inheritance (monohybrid, dihybrid, sex-linked, and genes linked
on the same chromosomes) can be predicted from data if one is given the parent
or offspring genotypes or phenotypes. Two organisms, with genotypes BbDD and
BBDd, are mated. Assuming independent assortment of the B/b and D/d genes,
determine the genotypic ratios in offspring that would occur.
A)
1/2 BBDD 1/2 bbdd
B)
1/4 BBDD 1/4 BbDD 1/4 BBDd 1/4 BbDd
C)
9/16 BBDD 3/16 BbDD 3/16 BBDd
1/16 bbdd
D)
1/4 BBDD 1/2 BbDd 1/4 bbdd
Campbell Biology, 10e (Reece)
Chapter 15 The
Chromosomal Basis of Inheritance
1)
When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed
flies. Remarkably, all the white-eyed flies were male. What was the explanation
for this result?
A)
The gene involved is on the Y chromosome.
B)
The gene involved is on the X chromosome.
C)
The gene involved is on an autosome, but only in males.
D)
Other male-specific factors influence eye color in flies.
2)
Which of the following is the meaning of the chromosome theory of inheritance
as expressed in the early twentieth century?
A)
Individuals inherit particular chromosomes attached to genes.
B)
Mendelian genes are at specific loci on the chromosome and, in turn, segregate
during meiosis.
C)
No more than a single pair of chromosomes can be found in a healthy normal
cell.
D)
Natural selection acts on certain chromosome arrays rather than on genes.
3)
Males are more often affected by sex-linked traits than females because _____.
A)
male hormones such as testosterone often alter the effects of mutations on the
X chromosome
B)
female hormones such as estrogen often compensate for the effects of mutations
on the X chromosome
C)
X chromosomes in males generally have more mutations than X chromosomes in
females
D)
males are hemizygous for the X chromosome
4)
SRY is best described as _____.
A)
a gene present on the X chromosome that triggers female development
B)
an autosomal gene that is required for the expression of genes on the Y
chromosome
C)
a gene region present on the Y chromosome that triggers male development
D)
an autosomal gene that is required for the expression of genes on the X
chromosome
5)
In cats, black fur color is caused by an X-linked allele; the other allele at
this locus causes orange color. The heterozygote is tortoiseshell. What kinds
of offspring would you expect from the cross of a black female and an orange
male?
A)
tortoiseshell females; tortoiseshell males
B)
black females; orange males
C)
tortoiseshell females; black males
D)
orange females; black males
6)
Red-green color blindness is a sex-linked recessive trait in humans. Two people
with normal color vision have a color-blind son. What are the genotypes of the
parents?
A)
XnXn and XnY
B)
XNXN and
XnY
C)
XNXN and XNY
D)
XNXn and XNY
7)
Cinnabar eyes is a sex-linked, recessive characteristic in fruit flies. If a
female having cinnabar eyes is crossed with a wild-type male, what percentage
of the F1 males will have cinnabar eyes?
A)
0%
B)
25%
C)
50%
D)
100%
8)
Normally, only female cats have the tortoiseshell phenotype because _____.
A)
a male inherits only one allele of the X-linked gene controlling hair color
B)
the Y chromosome has a gene blocking orange coloration
C)
only males can have Barr bodies
D)
multiple crossovers on the Y chromosome prevent orange pigment production
9)
In birds, sex is determined by a ZW chromosome scheme. Males are ZZ
and females are ZW. A recessive lethal allele that causes death of the
embryo is sometimes present on the Z chromosome in pigeons. What would be the
sex ratio in the offspring of a cross between a male that is heterozygous for
the lethal allele and a normal female?
A)
2:1 male to female
B)
1:2 male to female
C)
1:1 male to female
D)
3:1 male to female
10)
Sex determination in mammals is due to the SRY gene. Which of the
following could allow a person with an XX karyotype to develop a male
phenotype?
A)
the loss of the SRY gene from an autosome
B)
translocation of SRY to a X chromosome
C)
a person with an extra autosomal chromosome
D)
a person with one normal and one shortened (deleted) X
11)
In humans, clear gender differentiation occurs, not at fertilization, but after
the second month of gestation. What is the first event of this differentiation?
A)
formation of testosterone in male embryos
B)
formation of estrogens in female embryos
C)
activation of SRY in male embryos and masculinization of the gonads
D)
activation of SRY in females and feminization of the gonads
12)
Duchenne muscular dystrophy is a serious condition caused by a recessive allele
of a gene on the human X chromosome. The patients have muscles that weaken over
time because they have absent or decreased dystrophin, a muscle protein. They
rarely live past their twenties. How likely is it for a woman to have this
condition?
A)
Women can never have this condition.
B)
One-fourth of the daughters of an affected man would have this condition.
C)
One-half of the daughters of an affected father and a carrier mother could have
this condition.
D)
Only if a woman is XXX could she have this condition.
13)
All female mammals have one active X chromosome per cell instead of two. What
causes this?
A)
activation of the XIST gene on the X chromosome that will become the
Barr body
B)
activation of the BARR gene on one X chromosome, which then becomes
inactive
C)
inactivation of the XIST gene on the X chromosome derived from the male
parent
D)
attachment of methyl (CH3) groups to the X chromosome that will remain active
14)
A man who is an achondroplastic dwarf with normal vision marries a color-blind
woman of normal height. The man's father was six feet tall, and both the
woman's parents were of average height. Achondroplastic dwarfism is autosomal
dominant, and red-green color blindness is X-linked recessive. How many of
their daughters might be expected to be color-blind dwarfs?
A)
none
B)
half
C)
one out of four
D)
three out of four
15)
A man who is an achondroplastic dwarf with normal vision marries a color-blind
woman of normal height. The man's father was six feet tall, and both the
woman's parents were of average height. Achondroplastic dwarfism is autosomal
dominant, and red-green color blindness is X-linked recessive. What proportion
of their sons would be color-blind and of normal height?
A)
none
B)
half
C)
one out of four
D)
all
16)
Pseudohypertrophic muscular dystrophy is a human disorder that causes gradual
deterioration of the muscles. Only boys are affected, and they are always born
to phenotypically normal parents. Due to the severity of the disease, the boys
die in their teens. Is this disorder likely to be caused by a dominant or
recessive allele? Is its inheritance sex-linked or autosomal?
A)
dominant, sex-linked
B)
recessive, autosomal
C)
recessive, sex-linked
D)
incomplete dominant, sex-linked
17)
In birds, sex is determined by a ZW chromosome scheme that is much like the
typical XY scheme seen in humans and many other organisms, except that the
system is reversed: Males are ZZ (similar to XX in humans) and females are ZW
(similar to XY in humans). A lethal recessive allele that causes death of the
embryo occurs on the Z chromosome in pigeons. What would be the sex ratio in
the offspring of a cross between a male heterozygous for the lethal allele and
a normal female?
A)
1:1 male to female
B)
3:1 male to female
C)
1:2 male to female
D)
2:1 male to female
18)
A recessive allele on the X chromosome is responsible for red-green color
blindness in humans. A woman with normal vision whose father is color blind
marries a color-blind male. What is the probability that this couple's first
son will be color blind?
A)
1/4
B)
1/2
C)
2/3
D)
3/4
19)
A man who carries an allele of an X-linked gene will pass it on to _____.
A)
all of his daughters
B)
half of his daughters
C)
all of his sons
D)
all of his children
20)
Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as a recessive
allele of an X-linked gene in humans. A woman whose father suffered from G6PD
marries a normal man.
(a)
What proportion of their sons is expected to be G6PD?
(b)
If the husband was not normal but was G6PD deficient, would you change your
answer in part (a)?
A)
(a) 100%; (b) no
B)
(a) 1/2; (b) yes
C)
(a) 1/2; (b) no
D)
(a) zero; (b) no
21)
In a Drosophila experiment, a cross was made between homozygous
wild-type females and yellow-bodied males. All of the resulting F1s were
phenotypically wild type. However, adult flies of the F2 generation (resulting from matings of the F1s) had the
characteristics shown in the figure above. Consider the following questions:
(a)
Is the mutant allele for yellow body recessive or dominant?
(b)
Is the yellow locus autosomal (not X-linked) or X-linked?
A)
(a) recessive; (b) X-linked
B)
(a) recessive; (b) not X-linked
C)
(a) dominant; (b) X-linked
D)
(a) dominant; (b) not X-linked
22)
Sturtevant provided genetic evidence for the existence of four pairs of
chromosomes in Drosophila in which of these ways?
A)
There are four major functional classes of genes in Drosophila.
B)
Drosophila genes cluster into four distinct groups of linked genes.
C)
The overall number of genes in Drosophila is a multiple of four.
D)
Drosophila genes have, on average, four different alleles.
23)
Which of the following statements is true of linkage?
A)
The closer two genes are on a chromosome, the lower the probability that a
crossover will occur between them.
B)
The observed frequency of recombination of two genes that are far apart from
each other has a maximum value of 100%.
C)
All of the traits that Mendel studied—seed color, pod shape, flower color, and
others—are due to genes linked on the same chromosome.
D)
Linked genes are found on different chromosomes.
24)
How would one explain a testcross involving F1 dihybrid flies in which more parental-type
offspring than recombinant-type offspring are produced?
A)
The two genes are closely linked on the same chromosome.
B)
The two genes are linked but on different chromosomes.
C)
Recombination did not occur in the cell during meiosis.
D)
Both of the characters are controlled by more than one gene.
25)
What does a frequency of recombination of 50% indicate?
A)
The two genes are likely to be located on different chromosomes.
B)
All of the offspring have combinations of traits that match one of the two
parents.
C)
The genes are located on sex chromosomes.
D)
Abnormal meiosis has occurred.
26)
What is the definition of one map unit?
A)
the physical distance between two linked genes
B)
a 1% frequency of recombination between two genes
C)
1 nanometer of distance between two genes
D)
the recombination frequency between two genes assorting independently
27)
Recombination between linked genes comes about for what reason?
A)
Nonrecombinant chromosomes break and then rejoin with one another.
B)
Independent assortment sometimes fails.
C)
Linked genes travel together at anaphase.
D)
Crossovers between these genes result in chromosomal exchange.
28)
What is an adaptive advantage of recombination between linked genes?
A)
Recombination is required for independent assortment.
B)
Recombination must occur or genes will not assort independently.
C)
New allele combinations are acted upon by natural selection.
D)
The forces on the cell during meiosis II results in recombination.
29)
Map units on a linkage map cannot be relied upon to calculate physical
distances on a chromosome for which of the following reasons?
A)
The frequency of crossing over varies along the length of the chromosome.
B)
The relationship between recombination frequency and map units is different in
every individual.
C)
Physical distances between genes change during the course of the cell cycle.
D)
The gene order on the chromosomes is slightly different in every individual.
The
following is a map of four genes on a chromosome.
30)
Between which two genes would you expect the highest frequency of
recombination?
A)
A and W
B)
E and G
C)
A and E
D)
A and G
31)
In a series of mapping experiments, the recombination frequencies for four
different linked genes of Drosophila were determined as shown in the
figure above. What is the order of these genes on a chromosome map?
A)
rb-cn-vg-b
B)
cn-rb-b-vg
C)
b-rb-cn-vg
D)
vg-cn-b-rb
Use
the following information to answer the question(s) below.
A
plantlike organism on the planet Pandora can have three recessive genetic
traits: bluish leaves, due to an allele (a) of gene A; a
feathered stem, due to an allele (b) of gene B; and hollow roots
due to an allele (c) of gene C. The three genes are linked and
recombine as follows:
A
geneticist did a testcross with an organism that had been found to be
heterozygous for the three recessive traits and she was able to identify
progeny of the following phenotypic distribution (+ = wild type):
|
Phenotypes
|
Leaves
|
Stems
|
Roots
|
Number
|
|
1
|
a
|
+
|
+
|
14
|
|
2
|
a
|
+
|
c
|
0
|
|
3
|
a
|
b
|
+
|
32
|
|
4
|
a
|
b
|
c
|
440
|
|
5
|
+
|
b
|
+
|
0
|
|
6
|
+
|
b
|
c
|
16
|
|
7
|
+
|
+
|
c
|
28
|
|
8
|
+
|
+
|
+
|
470
|
|
|
|
|
Total
|
1000
|
32)
Which of the following are the phenotypes of the parents in this cross?
A)
2 and 5
B)
1 and 6
C)
4 and 8
D)
3 and 7
33)
Which of the progeny phenotypes will require recombination between genes A
and B?
A)
1, 2, 5, and 6
B)
1, 3, 6, and 7
C)
2, 4, 5, and 8
D)
2, 3, 5, and 7
34)
If recombination frequency is equal to distance in map units, what is the
approximate distance between genes A and B?
A)
3 map units
B)
6 map units
C)
15 map units
D)
30 map units
35)
What is the greatest benefit of having used a testcross for this experiment?
A)
The homozygous recessive parents are obvious to the naked eye.
B)
The homozygous parents are the only ones whose crossovers make a difference.
C)
The phenotypes of the progeny reveal the allelic content of the gamete from the
heterozygous parent.
D)
All of the progeny will be heterozygous.
36)
The greatest distance among the three genes is between a and c.
What does this mean?
A)
Gene c is between a and b.
B)
Genes are in the order: a—b—c.
C)
Gene a is not recombining with c.
D)
Gene a is between b and c.
37)
What is the reason that closely linked genes are typically inherited together?
A)
They are located close together on the same chromosome.
B)
The number of genes in a cell is greater than the number of chromosomes.
C)
Alleles are paired together during meiosis.
D)
Genes align that way during metaphase I of meiosis.
38)
A homozygous tomato plant with red fruit and yellow flowers was crossed with a
homozygous tomato plant with golden fruit and white flowers. The F1 all had red fruit and yellow flowers. The F1 were testcrossed by crossing them to
homozygous recessive individuals and the following offspring were obtained:
Red
fruit and yellow flowers—41
Red
fruit and white flowers—7
Golden
fruit and yellow flowers—8
Golden
fruit and white flowers—44
How
many map units separate these genes?
A)
17.6
B)
15
C)
17.1
D)
18.1
39)
In Drosophila melanogaster, vestigial wings are caused by a recessive
allele of a gene that is linked to a gene with a recessive allele that causes
black body color. Morgan crossed black-bodied, normal-winged females and
gray-bodied, vestigial-winged males. The F1 were all gray bodied, normal winged. The F1 females were crossed to homozygous recessive
males to produce testcross progeny. Morgan calculated the map distance to be 17
map units. Which of the following is correct about the testcross progeny?
A)
black-bodied, normal-winged flies = 17% of the total
B)
black-bodied, normal-winged flies PLUS gray-bodied, vestigial-winged flies =
17% of the total
C)
gray-bodied, normal-winged flies PLUS black-bodied, vestigial-winged flies =
17% of the total
D)
black-bodied, vestigial-winged flies = 17% of the total
40)
If cell X enters meiosis, and nondisjunction of one chromosome occurs in one of
its daughter cells during meiosis II, what will be the result at the completion
of meiosis?
A)
All the gametes descended from cell X will be diploid.
B)
Half of the gametes descended from cell X will be n + 1, and half will
be n - 1.
C)
1/4 of the gametes descended from cell X will be n + 1, 1/4 will be n
- 1, and 1/2 will be n.
D)
Two of the four gametes descended from cell X will be haploid, and two will be
diploid.
41)
One possible result of chromosomal breakage is for a fragment to join a
nonhomologous chromosome. What is this alteration called?
A)
deletion
B)
inversion
C)
translocation
D)
duplication
42)
A nonreciprocal crossover causes which of the following products?
A)
deletion only
B)
duplication only
C)
nondisjunction
D)
deletion and duplication
43)
Of the following human aneuploidies, which is the one that generally has the
most severe impact on the health of the individual?
A)
47, trisomy 21
B)
47, XXY
C)
47, XXX
D)
45, X
44)
A phenotypically normal prospective couple seeks genetic counseling because the
man knows that he has a translocation of a portion of his chromosome 4 that has
been exchanged with a portion of his chromosome 12. Although his translocation
is balanced, he and his wife want to know the probability that his sperm will
be abnormal. What is your prognosis regarding his sperm?
A)
1/4 will carry the two normal chromosomes, 4 and 12, 1/4 will have only the two
translocation chromosomes and no normal chromosomes 4 and 12, and 1/2 will have
both normal and translocated chromosomes.
B)
All will carry the same translocation as the father.
C)
None will carry the translocation.
D)
1/2 will be normal and the rest will have the father's translocation.
45)
Abnormal chromosomes are frequently found in malignant tumors. Errors such as
translocations may place a gene in close proximity to different control
regions. Which of the following might then occur to make the cancer worse?
A)
an increase in nondisjunction
B)
expression of inappropriate gene products
C)
a decrease in mitotic frequency
D)
failure of the cancer cells to multiply
46)
A couple has a child with Down syndrome. The mother is 39 years old at the time
of delivery. Which of the following is the most probable cause of the child's
condition?
A)
The woman inherited this tendency from her parents.
B)
The mother had a chromosomal duplication.
C)
One member of the couple underwent nondisjunction in somatic cell production.
D)
The mother most likely underwent nondisjunction during gamete production.
47)
What is a syndrome?
A)
a characteristic facial appearance
B)
a trait that leads to cancer at some stage in life
C)
a group of traits typically found in conjunction with a particular chromosomal
aberration or gene mutation
D)
a specific characteristic that appears in conjunction with one specific
aneuploidy
48)
Which of the following is known as a Philadelphia chromosome?
A)
a human chromosome 22 that has had a specific translocation
B)
a human chromosome 9 that is found only in one type of cancer
C)
an animal chromosome found primarily in the mid-Atlantic area of the United
States
D)
a chromosome found only in mitochondria
49)
Which of the following is generally true of aneuploidies in newborns?
A)
A monosomy is more frequent than a trisomy.
B)
Monosomy X is the only viable monosomy known to occur in humans.
C)
Human aneuploidy usually conveys an adaptive advantage in humans.
D)
An aneuploidy resulting in the deletion of a chromosome segment is less serious
than a duplication.
50)
A woman is found to have forty-seven chromosomes, including three X
chromosomes. Which of the following describes her expected phenotype?
A)
a female with masculine characteristics such as facial hair
B)
an apparent male who is sterile
C)
healthy female of slightly above-average height
D)
a sterile female
51)
Which of the following is an example of monosomy?
A)
Turner's syndrome
B)
Klinefelter's syndrome
C)
Down syndrome
D)
trisomy X
52)
Genomic imprinting is generally due to the addition of methyl (-CH3) groups to C
nucleotides and chemical histone changes to silence a given gene. If this
depends on the sex of the parent who transmits the gene, which of the following
must be true?
A)
Genes required for early development stages must not be imprinted.
B)
Methylation of this kind must occur more in males than in females.
C)
Methylation must be reversible in ovarian and testicular cells.
D)
The imprints are transmitted only to gamete-producing cells.
53)
Correns found that the inheritance of variegated color on the leaves of certain
plants was determined only by the maternal parent. What phenomenon explains
this pattern?
A)
ribosome structure
B)
chloroplast inheritance
C)
genomic imprinting
D)
sex-linkage
54)
Mitochondrial DNA is primarily involved in coding for proteins needed for
protein complexes of the electron transport chain and ATP synthase. Therefore,
mutations in mitochondrial genes would most affect _____.
A)
DNA synthesis in cells of the immune system
B)
the movement of oxygen into erythrocytes
C)
generation of ATP in muscle cells
D)
the storage of urine in the urinary bladder
55)
The pedigree in the figure above shows the transmission of a trait in a
particular family. Based on this pattern of transmission, the trait is most
likely _____.
A)
mitochondrial
B)
sex-linked dominant
C)
sex-linked recessive
D)
autosomal dominant
56)
A certain kind of snail can have a right-handed direction of shell coiling (DD
or Dd) or left-handed coiling (dd). However, if direction of coiling
is due to a protein deposited by the mother in the egg cytoplasm, then a Dd
egg-producing snail and a dd sperm-producing snail will have offspring
of which genotype(s) and phenotype(s)?
A)
1/2 Dd:1/2 dd; all right-coiling
B)
all Dd; all right-coiling
C)
1/2 Dd:1/2 dd; half right-coiling and half left-coiling
D)
all Dd; half right-coiling and half left-coiling
57)
During meiosis, a defect occurs in a cell that results in the failure of
microtubules, spindle fibers, to bind at the kinetochores, a protein structure
on chromatids where the spindle fibers attach during cell division to pull
sister chromatids apart. Which of the following is the most likely result of
such a defect?
A)
New microtubules with more effective binding capabilities to kinetochores will
be synthesized to compensate for the defect.
B)
Excessive cell divisions will occur resulting in cancerous tumors and an
increase in the chromosome numbers known as polyploidy.
C)
The defect will be bypassed in order to and ensure normal chromosome
distribution in the new cells.
D)
The resulting cells will not receive the correct number of chromosomes in the
gametes, a condition known as aneuploidy.
58)
Inheritance patterns cannot always be explained by Mendel’s models of
inheritance. If a pair of homologous chromosomes fails to separate during
meiosis I, select the choice
that
shows the chromosome number of the four resulting gametes with respect to the
normal haploid number (n)?
A)
n+1; n+1; n-1; n-1
B)
n+1; n-1; n; n
C)
n+1; n-1; n-1; n-1
D)
n+1; n+1; n; n
Campbell Biology, 10e (Reece)
Chapter 16 The
Molecular Basis of Inheritance
1)
In his transformation experiments, what did Griffith observe?
A)
Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic
strain can convert some of the living cells into the pathogenic form.
B)
Mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic
strain makes the pathogenic strain nonpathogenic.
C)
Infecting mice with nonpathogenic strains of bacteria makes them resistant to
pathogenic strains.
D)
Mice infected with a pathogenic strain of bacteria can spread the infection to
other mice.
2)
How do we describe transformation in bacteria?
A)
the creation of a strand of DNA from an RNA molecule
B)
the creation of a strand of RNA from a DNA molecule
C)
the infection of cells by a phage DNA molecule
D)
assimilation of external DNA into a cell
3)
After mixing a heat-killed, phosphorescent (light-emitting) strain of bacteria
with a living, nonphosphorescent strain, you discover that some of the living
cells are now phosphorescent. Which observation(s) would provide the best
evidence that the ability to phosphoresce is a heritable trait?
A)
evidence that DNA was passed from the heat-killed strain to the living strain
B)
evidence that protein passed from the heat-killed strain to the living strain
C)
especially bright phosphorescence in the living strain
D)
phosphorescence in descendants of the living cells
4)
In trying to determine whether DNA or protein is the genetic material, Hershey
and Chase made use of which of the following facts?
A)
DNA contains sulfur, whereas protein does not.
B)
DNA contains phosphorus, whereas protein does not.
C)
DNA contains nitrogen, whereas protein does not.
D)
DNA contains purines, whereas protein includes pyrimidines.
5)
Which of the following investigators was (were) responsible for the following
discovery?
In
DNA from any species, the amount of adenine equals the amount of thymine, and
the amount of guanine equals the amount of cytosine.
A)
Alfred Hershey and Martha Chase
B)
Oswald Avery, Maclyn McCarty, and Colin MacLeod
C)
Erwin Chargaff
D)
Matthew Meselson and Franklin Stahl
6)
Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism.
Approximately what percentage of the nucleotides in this sample will be
thymine?
A)
8%
B)
16%
C)
42%
D)
58%
7)
It became apparent to Watson and Crick after completion of their model that the
DNA molecule could carry a vast amount of hereditary information in which of
the following?
A)
sequence of bases
B)
phosphate-sugar backbones
C)
complementary pairing of bases
D)
side groups of nitrogenous bases
8)
In an analysis of the nucleotide composition of DNA, which of the following
will be found?
A)
A = C
B)
A = G and C = T
C)
A + C = G + T
D)
G + C = T + A
9)
For a science fair project, two students decided to repeat the Hershey and
Chase experiment, with modifications. They decided to label the nitrogen of the
DNA, rather than the phosphate. They reasoned that each nucleotide has only one
phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide
a stronger signal than labeling the phosphates. Why won't this experiment work?
A)
There is no radioactive isotope of nitrogen.
B)
Radioactive nitrogen has a half-life of 100,000 years, and the material would
be too dangerous for too long.
C)
Although there are more nitrogens in a nucleotide, labeled phosphates actually
have sixteen extra neutrons; therefore, they are more radioactive.
D)
Amino acids (and thus proteins) also have nitrogen atoms; thus, the
radioactivity would not distinguish between DNA and proteins.
10)
Hershey and Chase set out to determine what molecule served as the unit of
inheritance. They completed a series of experiments in which E. coli was
infected by a T2 virus. Which molecular component of the T2 virus actually
ended up inside the cell?
A)
protein
B)
RNA
C)
ribosome
D)
DNA
11)
In the polymerization of DNA, a phosphodiester bond is formed between a
phosphate group of the nucleotide being added and _____ of the last nucleotide
in the polymer.
A)
the phosphate
phosphate
B)
C6
C)
the OH
OH
D)
a nitrogen from the nitrogen-containing base
12)
Replication in prokaryotes differs from replication in eukaryotes for which of
the following reasons?
A)
Prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not.
B)
Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic
chromosomes have many.
C)
The rate of elongation during DNA replication is slower in prokaryotes than in
eukaryotes.
D)
Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do
not.
13)
What is meant by the description "antiparallel" regarding the strands
that make up DNA?
A)
The twisting nature of DNA creates nonparallel strands.
B)
The 5' to 3' direction of one strand runs counter to the to direction of the other strand.
to direction of the other strand.
C)
Base pairings create unequal spacing between the two DNA strands.
D)
One strand contains only purines and the other contains only pyrimidines.
14)
Suppose you are provided with an actively dividing culture of E. coli
bacteria to which radioactive thymine has been added. What would happen if a
cell replicates once in the presence of this radioactive base?
A)
One of the daughter cells, but not the other, would have radioactive DNA.
B)
Neither of the two daughter cells would be radioactive.
C)
All four bases of the DNA would be radioactive.
D)
DNA in both daughter cells would be radioactive.
15)
In E. coli, there is a mutation in a gene called dnaB that alters
the helicase that normally acts at the origin. Which of the following would you
expect as a result of this mutation?
A)
Additional proofreading will occur.
B)
No replication fork will be formed.
C)
Replication will occur via RNA polymerase alone.
D)
Replication will require a DNA template from another source.
16)
In E. coli, which enzyme catalyzes the elongation of a new DNA strand in
the → direction?
→ direction?
A)
primase
B)
DNA ligase
C)
DNA polymerase III
D)
helicase
17)
Eukaryotic telomeres replicate differently than the rest of the chromosome.
This is a consequence of which of the following?
A)
the evolution of telomerase enzyme
B)
DNA polymerase that cannot replicate the leading strand template to its end
end
C)
gaps left at the end of the lagging strand
end of the lagging strand
D)
gaps left at the end of the lagging strand because of the need
for a primer
end of the lagging strand because of the need
for a primer
18)
How does the enzyme telomerase meet the challenge of replicating the ends of
linear chromosomes?
A)
It adds a single cap structure that resists degradation by
nucleases.
cap structure that resists degradation by
nucleases.
B)
It causes specific double-strand DNA breaks that result in blunt ends on both
strands.
C)
It catalyzes the lengthening of telomeres, compensating for the shortening that
could occur during replication without telomerase activity.
D)
It adds numerous GC pairs, which resist hydrolysis and maintain chromosome
integrity.
19)
The DNA of telomeres has been highly conserved throughout the evolution of
eukaryotes. This most likely reflects _____.
A)
the low frequency of mutations occurring in this DNA
B)
continued evolution of telomeres
C)
that new mutations in telomeres have been advantageous
D)
a critical function of telomeres
20)
At a specific area of a chromosome, the sequence of nucleotides below is
present where the chain opens to form a replication fork:
C C T A G G C T G C A A T C C
An
RNA primer is formed starting at the underlined T (T) of the template.
Which of the following represents the primer sequence?
A)
G C C T A G G
G C C T A G G
B)
A C G T T A G G
A C G T T A G G
C)
A C G U U A G G
A C G U U A G G
D)
G C C U A G G
G C C U A G G
21)
In E. coli, to repair a thymine dimer by nucleotide excision repair, in
which order do the necessary enzymes act?
A)
nuclease, DNA polymerase III, RNA primase
B)
helicase, DNA polymerase I, DNA ligase
C)
DNA ligase, nuclease, helicase
D)
nuclease, DNA polymerase I, DNA ligase
22)
In E. coli, what is the function of DNA polymerase III?
A)
to unwind the DNA helix during replication
B)
to seal together the broken ends of DNA strands
C)
to add nucleotides to the end of a growing DNA strand
end of a growing DNA strand
D)
to degrade damaged DNA molecules
23)
The difference between ATP and the nucleoside triphosphates used during DNA
synthesis is that _____.
A)
the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar
ribose
B)
the nucleoside triphosphates have two phosphate groups; ATP has three phosphate
groups
C)
ATP contains three high-energy bonds; the nucleoside triphosphates have two
D)
ATP is found only in human cells; the nucleoside triphosphates are found in all
animal and plant cells
24)
The leading and the lagging strands differ in that _____.
A)
the leading strand is synthesized in the same direction as the movement of the
replication fork, and the lagging strand is synthesized in the opposite
direction
B)
the leading strand is synthesized by adding nucleotides to the end of the growing strand, and the lagging
strand is synthesized by adding nucleotides to the end
end of the growing strand, and the lagging
strand is synthesized by adding nucleotides to the end
C)
the lagging strand is synthesized continuously, whereas the leading strand is
synthesized in short fragments that are ultimately stitched together
D)
the leading strand is synthesized at twice the rate of the lagging strand
25)
A new DNA strand elongates only in the to direction because _____.
to direction because _____.
A)
DNA polymerase begins adding nucleotides at the end of the template
end of the template
B)
the polarity of the DNA molecule prevents addition of nucleotides at the end
end
C)
replication must progress toward the replication fork
D)
DNA polymerase can add nucleotides only to the free end
end
26)
What is the function of topoisomerase?
A)
relieving strain in the DNA ahead of the replication fork
B)
elongating new DNA at a replication fork by adding nucleotides to the existing
chain
C)
unwinding of the double helix
D)
stabilizing single-stranded DNA at the replication fork
27)
What is the role of DNA ligase in the elongation of the lagging strand during
DNA replication?
A)
It synthesizes RNA nucleotides to make a primer.
B)
It joins Okazaki fragments together.
C)
It unwinds the parental double helix.
D)
It stabilizes the unwound parental DNA.
28)
Which of the following help(s) to hold the DNA strands apart while they are
being replicated?
A)
primase
B)
ligase
C)
DNA polymerase
D)
single-strand DNA binding proteins
29)
Individuals with the disorder xeroderma pigmentosum are hypersensitive to
sunlight. This occurs because their cells cannot_____.
A)
replicate DNA
B)
undergo mitosis
C)
exchange DNA with other cells
D)
repair thymine dimers
30)
Which of the following would you expect of a eukaryote lacking telomerase?
A)
a high probability of somatic cells becoming cancerous
B)
an inability to produce Okazaki fragments
C)
an inability to repair thymine dimers
D)
a reduction in chromosome length in gametes
31)
In the late 1950s, Meselson and Stahl grew bacteria in a medium containing
"heavy" nitrogen (15N) and then transferred them to a medium
containing 14N.
Which of the results in the figure above would be expected after one round of
DNA replication in the presence of 14N?
A)
A
B)
B
C)
C
D)
D
32)
A space probe returns with a culture of a microorganism found on a distant
planet. Analysis shows that it is a carbon-based life-form that has DNA. You
grow the cells in 15N medium for several generations and then transfer them to 14N medium.
Which pattern in the figure above would you expect if the DNA was replicated in
a conservative manner?
A)
A
B)
B
C)
C
D)
D
33)
After the first replication was observed in their experiments testing the
nature of DNA replication, Meselson and Stahl could be confident of which of
the following conclusions?
A)
Replication is semi-conservative.
B)
Replication is not dispersive.
C)
Replication is not conservative.
D)
Replication is neither dispersive nor conservative.
34)
You briefly expose bacteria undergoing DNA replication to radioactively labeled
nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA
separates into two classes. One class of labeled DNA includes very large
molecules (thousands or even millions of nucleotides long), and the other
includes short stretches of DNA (several hundred to a few thousand nucleotides
in length). These two classes of DNA probably represent _____.
A)
leading strands and Okazaki fragments
B)
lagging strands and Okazaki fragments
C)
Okazaki fragments and RNA primers
D)
leading strands and RNA primers
35)
Within a double-stranded DNA molecule, adenine forms hydrogen bonds with
thymine and cytosine forms hydrogen bonds with guanine. This arrangement _____.
A)
allows variable width of the double helix
B)
permits complementary base pairing
C)
determines the tertiary structure of a DNA molecule
D)
determines the type of protein produced
36)
Semiconservative replication involves a template. What is the template?
A)
single-stranded binding proteins
B)
DNA polymerase
C)
one strand of the DNA molecule
D)
an RNA molecule
37)
DNA is synthesized through a process known as _____.
A)
semiconservative replication
B)
conservative replication
C)
translation
D)
transcription
38)
Who performed classic experiments that supported the semiconservative model of
DNA replication?
A)
Watson and Crick
B)
Meselson and Stahl
C)
Hershey and Chase
D)
Franklin and Wilkins
39)
DNA contains the template needed to copy itself, but it has no catalytic
activity in cells. What catalyzes the formation of phosphodiester bonds between
adjacent nucleotides in the DNA polymer being formed?
A)
ribozymes
B)
DNA polymerase
C)
ATP
D)
deoxyribonucleotide triphosphates
40)
What provides the energy for the polymerization reactions in DNA synthesis?
A)
ATP
B)
DNA polymerase
C)
breaking the hydrogen bonds between complementary DNA strands
D)
the deoxyribonucleotide triphosphate substrates
41)
Refer to the figure above. What bases will be added to the primer as DNA
replication proceeds? The bases should appear in the new strand in the order
that they will be added starting at the end of the primer.
end of the primer.
A)
C, A, G, C, A, G, A
B)
T, C, T, G, C, T, G
C)
A, G, A, C, G, A, C
D)
G, T, C, G, T, C, T
42)
What is the difference between the leading strand and the lagging strand in DNA
replication?
A)
The leading strand is synthesized in the → direction in a discontinuous fashion, while
the lagging strand is synthesized in the → direction in a continuous fashion.
→ direction in a discontinuous fashion, while
the lagging strand is synthesized in the → direction in a continuous fashion.
B)
The leading strand is synthesized continuously in the → direction, while the lagging strand is
synthesized discontinuously in the → direction.
→ direction, while the lagging strand is
synthesized discontinuously in the → direction.
C)
The leading strand requires an RNA primer, whereas the lagging strand does not.
D)
There are different DNA polymerases involved in elongation of the leading
strand and the lagging strand.
43)
What is a major difference between eukaryotic DNA replication and prokaryotic
DNA replication?
A)
Prokaryotic replication does not require a primer.
B)
Prokaryotic chromosomes have a single origin of replication, while eukaryotic
chromosomes have multiple origins of replication.
C)
DNA replication in prokaryotic cells is conservative. DNA replication in
eukaryotic cells is semi-conservative.
D)
DNA polymerases of prokaryotes can add nucleotides to both and ends of DNA strands, while those of eukaryotes
function only in the → direction.
and ends of DNA strands, while those of eukaryotes
function only in the → direction.
44)
What is a telomere?
A)
the mechanism that holds two sister chromatids together
B)
DNA replication during telophase
C)
the site of origin of DNA replication
D)
the ends of linear chromosomes
45)
Telomere shortening puts a limit on the number of times a cell can divide.
Research has shown that telomerase can extend the life span of cultured human
cells. How might adding telomerase affect cellular aging?
A)
Telomerase will speed up the rate of cell proliferation.
B)
Telomerase eliminates telomere shortening and retards aging.
C)
Telomerase shortens telomeres, which delays cellular aging.
D)
Telomerase would have no effect on cellular aging.
46)
Telomere shortening is a problem in which types of cells?
A)
only prokaryotic cells
B)
only eukaryotic cells
C)
cells in prokaryotes and eukaryotes
47)
Which of the following cells have reduced or very little active telomerase
activity?
A)
most normal somatic cells
B)
most normal germ cells
C)
most cancer cells
48)
Researchers found E. coli that had mutation rates one hundred times
higher than normal. Which of the following is the most likely cause of these
results?
A)
The single-stranded binding proteins were malfunctioning.
B)
There were one or more mismatches in the RNA primer.
C)
The proofreading mechanism of DNA polymerase was not working properly.
D)
The DNA polymerase was unable to add bases to the end of the growing nucleic acid chain.
end of the growing nucleic acid chain.
49)
In a healthy cell, the rate of DNA repair is equal to the rate of DNA mutation.
When the rate of repair lags behind the rate of mutation, what is a possible
fate of the cell?
A)
The cell can be transformed to a cancerous cell.
B)
RNA may be used instead of DNA as inheritance material.
C)
The cell will become embryonic.
D)
DNA synthesis will continue by a new mechanism.
50)
Which of the following statements describes a eukaryotic chromosome?
A)
a single strand of DNA
B)
a series of nucleosomes wrapped around two DNA molecules
C)
a chromosome with different numbers of genes in different cell types of an
organism
D)
a single linear molecule of double-stranded DNA plus proteins
51)
If a cell were unable to produce histone proteins, which of the following would
be a likely effect?
A)
There would be an increase in the amount of "satellite" DNA produced
during centrifugation.
B)
The cell's DNA couldn't be packed into its nucleus.
C)
Spindle fibers would not form during prophase.
D)
Amplification of other genes would compensate for the lack of histones.
52)
Which of the following statements is true of histones?
A)
Each nucleosome consists of two molecules of histone H1.
B)
Histone H1 is not present in the nucleosome bead; instead, it draws the
nucleosomes together.
C)
The carboxyl end of each histone extends outward from the nucleosome and is
called a "histone tail."
D)
Histones are found in mammals, but not in other animals or in plants or fungi.
53)
Why do histones bind tightly to DNA?
A)
Histones are positively charged, and DNA is negatively charged.
B)
Histones are negatively charged, and DNA is positively charged.
C)
Both histones and DNA are strongly hydrophobic.
D)
Histones are covalently linked to the DNA.
54)
Which of the following represents the order of increasingly higher levels of
organization of chromatin?
A)
nucleosome, 30-nm chromatin fiber, looped domain
B)
looped domain, 30-nm chromatin fiber, nucleosome
C)
nucleosome, looped domain, 30-nm chromatin fiber
D)
30-nm chromatin fiber, nucleosome, looped domain
55)
Which of the following statements describes chromatin?
A)
Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA.
B)
Both heterochromatin and euchromatin are found in the cytoplasm.
C)
Heterochromatin is highly condensed, whereas euchromatin is less compact.
D)
Euchromatin is not transcribed, whereas heterochromatin is transcribed.
56)
Which of the following is most critical for the association between histones
and DNA?
A)
Histones are small proteins.
B)
Histones are highly conserved (that is, histones are very similar in every eukaryote).
C)
There are at least five different histone proteins in every eukaryote.
D)
Histones are positively charged.
57)
In E. coli replication the enzyme primase is used to attach a 5 to 10 base
ribonucleotide strand complementary to the parental DNA strand. The RNA strand
serves as a starting point for the DNA
polymerase
that replicates the DNA. If a mutation occurred in the primase gene, which of
the following would you expect?
A)
Replication would only occur on the leading strand.
B)
Replication would only occur on the lagging strand.
C)
Replication would not occur on either the leading or lagging strand.
D)
Replication would not be affected as the enzyme primase in involved with RNA
synthesis.
58)
Hershey and Chase used a DNA-based virus for their work. What would the results
have been if they had used an RNA virus?
A)
With an RNA virus radioactive protein would have been in the final pellet.
B)
With an RNA virus radioactive RNA would have been in the final pellet.
C)
With an RNA virus neither sample would have had a radioactive pellet.
D)
With an RNA virus the protein shell would have been radioactive in both
samples.
59)
The lagging strand is characterized by a series of short segments of DNA
(Okazaki fragments) that will be joined together to form a finished lagging
strand. The experiments that led to the discovery of Okazaki
fragments
gave evidence for which of the following ideas?
A)
DNA polymerase is a directional enzyme that synthesizes leading and lagging
strands during replication.
B)
DNA is a polymer consisting of four monomers: adenine, thymine, guanine, and
cytosine.
C)
DNA is the genetic material.
D)
Bacterial replication is fundamentally different from eukaryotic replication.
The key shouldn’t be way longer than the distractors.
Campbell Biology, 10e (Reece)
Chapter 17 Gene
Expression: From Gene to Protein
1)
Garrod hypothesized that "inborn errors of metabolism" such as
alkaptonuria occur because _____.
A)
metabolic enzymes require vitamin cofactors, and affected individuals have
significant nutritional deficiencies
B)
enzymes are made of DNA, and affected individuals lack DNA polymerase
C)
certain metabolic reactions are carried out by ribozymes, and affected
individuals lack key splicing factors
D)
genes dictate the production of specific enzymes, and affected individuals have
genetic defects that cause them to lack certain enzymes
2)
A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The
corresponding codon for the mRNA transcribed is _____.
A)
UCA
UCA
B)
UGA
UGA
C)
TCA
TCA
D)
ACU
ACU
3)
The genetic code is essentially the same for all organisms. From this, one can
logically assume which of the following?
A)
A gene from an organism can theoretically be expressed by any other organism.
B)
DNA was the first genetic material.
C)
The same codons in different organisms translate into different amino acids.
D)
Different organisms have different types of amino acids.
4)
The figure above shows a simple metabolic pathway. According to Beadle and Tatum's
hypothesis, how many genes are necessary for this pathway?
A)
1
B)
2
C)
3
D)
It cannot be determined from the pathway.
5)
Refer to the metabolic pathway illustrated above. If A, B, and C are all
required for growth, a strain that is mutant for the gene-encoding enzyme A
would be able to grow on medium supplemented with _____.
A)
nutrient A only
B)
nutrient B only
C)
nutrient C only
D)
nutrients A and C
6)
Refer to the metabolic pathway illustrated above. If A, B, and C are all
required for growth, a strain mutant for the gene-encoding enzyme B would be
able to grow on medium supplemented with _____.
A)
nutrient A only
B)
nutrient B only
C)
nutrient C only
D)
nutrients A and C
The
following questions refer to this table of codons.
7)
A possible sequence of nucleotides in the template strand of DNA that would
code for the polypeptide sequence phe-leu-ile-val would be _____.
A)
TTG-CTA-CAG-TAG
TTG-CTA-CAG-TAG
B)
AUG-CTG-CAG-TAT
AUG-CTG-CAG-TAT
C)
AAA-AAT-ATA-ACA
AAA-AAT-ATA-ACA
D)
AAA-GAA-TAA-CAA
AAA-GAA-TAA-CAA
8)
What amino acid sequence will be generated, based on the following mRNA codon
sequence?
5'
AUG-UCU-UCG-UUA-UCC-UUG
A)
met-arg-glu-arg-glu-arg
B)
met-glu-arg-arg-glu-leu
C)
met-ser-leu-ser-leu-ser
D)
met-ser-ser-leu-ser-leu
9)
Refer to the figure above. What would the anticodon be for a tRNA that
transports phenylalanine to a ribosome?
A)
UUU
B)
AAA
C)
TTT
D)
CCC
10)
Which of the following contradicts the one-gene, one-enzyme hypothesis?
A)
A mutation in a single gene can result in a defective protein.
B)
Alkaptonuria results when individuals lack a single enzyme involved in the
catalysis of homogentisic acid.
C)
Sickle-cell anemia results in defective hemoglobin.
D)
A single antibody gene can code for different related proteins, depending on
the splicing that takes place post-transcriptionally.
11)
Which of the following is directly related to a single amino acid?
A)
the base sequence of the tRNA
B)
the amino acetyl tRNA synthase
C)
the three-base sequence of mRNA
D)
the complementarity of DNA and RNA
12)
In the process of transcription, _____.
A)
DNA is replicated
B)
RNA is synthesized
C)
proteins are synthesized
D)
mRNA attaches to ribosomes
13)
Codons are part of the molecular structure of _____.
A)
a protein
B)
mRNA
C)
tRNA
D)
rRNA
14)
What does it mean when we say the genetic code is redundant?
A)
A single codon can specify the addition of more than one amino acid.
B)
The genetic code is different for different domains of organisms.
C)
The genetic code is universal (the same for all organisms).
D)
More than one codon can specify the addition of the same amino acid.
15)
Once researchers identified DNA as the unit of inheritance, they asked how
information was transferred from the DNA in the nucleus to the site of protein
synthesis in the cytoplasm. What is the mechanism of information transfer in
eukarotes?
A)
DNA from a single gene is replicated and transferred to the cytoplasm, where it
serves as a template for protein synthesis.
B)
Messenger RNA is transcribed from a single gene and transfers information from
the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.
C)
Proteins transfer information from the nucleus to the ribosome, where protein
synthesis takes place.
D)
Transfer RNA takes information from DNA directly to a ribosome, where protein
synthesis takes place.
16)
According to the central dogma, what molecule should go in the blank?
DNA
→ _____ → Proteins
A)
mtDNA
B)
rRNA
C)
mRNA
D)
tRNA
17)
Codons are three-base sequences that specify the addition of a single amino
acid. How do eukaryotic codons and prokaryotic codons compare?
A)
Prokaryotic codons usually contain different bases than those of eukaryotes.
B)
Prokaryotic codons usually specify different amino acids than those of
eukaryotes.
C)
The translation of codons is mediated by tRNAs in eukaryotes, but translation
requires no intermediate molecules such as tRNAs in prokaryotes.
D)
Codons are a nearly universal language among all organisms.
18)
Which of the following occurs in prokaryotes but not in eukaryotes?
A)
post-transcriptional splicing
B)
concurrent transcription and translation
C)
translation in the absence of a ribosome
D)
gene regulation
19)
Which of the following statements best describes the termination of
transcription in prokaryotes?
A)
RNA polymerase transcribes through the polyadenylation signal, causing proteins
to associate with the transcript and cut it free from the polymerase.
B)
RNA polymerase transcribes through the terminator sequence, causing the
polymerase to separate from the DNA and release the transcript.
C)
Once transcription has initiated, RNA polymerase transcribes until it reaches
the end of the chromosome.
D)
RNA polymerase transcribes through a stop codon, causing the polymerase to stop
advancing through the gene and release the mRNA.
20)
In eukaryotes there are several different types of RNA polymerase. Which type
is involved in transcription of mRNA for a globin protein?
A)
RNA polymerase I
B)
RNA polymerase II
C)
RNA polymerase III
D)
primase
21)
Transcription in eukaryotes requires which of the following in addition to RNA
polymerase?
A)
start and stop codons
B)
ribosomes and tRNA
C)
several transcription factors
D)
aminoacyl-tRNA synthetase
22)
Which of the following best describes the significance of the TATA box in
eukaryotic promoters?
A)
It is the recognition site for a specific transcription factor.
B)
It sets the reading frame of the mRNA.
C)
It is the recognition site for ribosomal binding.
D)
Its significance has not yet been determined.
23)
Which of the following does not occur in prokaryotic gene expression, but does
occur in eukaryotic gene expression?
A)
mRNA, tRNA, and rRNA are transcribed.
B)
RNA polymerase binds to the promoter.
C)
A cap is added to the end of
the mRNA.
end of
the mRNA.
D)
RNA polymerase requires a primer to elongate the molecule.
24)
A ribozyme is _____.
A)
a catalyst that uses RNA as a substrate
B)
an RNA with catalytic activity
C)
an enzyme that catalyzes the association between the large and small ribosomal
subunits
D)
an enzyme that synthesizes RNA as part of the transcription process
25)
Alternative RNA splicing _____.
A)
is a mechanism for increasing the rate of translation
B)
can allow the production of proteins of different sizes and functions from a
single mRNA
C)
can allow the production of similar proteins from different RNAs
D)
increases the rate of transcription
26)
In the structural organization of many eukaryotic genes, individual exons may
be related to which of the following?
A)
the sequence of the intron that immediately precedes each exon
B)
the number of polypeptides making up the functional protein
C)
the various domains of the polypeptide product
D)
the number of start sites for transcription
27)
In an experimental situation, a student researcher inserts an mRNA molecule
into a eukaryotic cell after she has removed its cap and poly-A tail. Which of the following
would you expect her to find?
cap and poly-A tail. Which of the following
would you expect her to find?
A)
The mRNA is quickly converted into a ribosomal subunit.
B)
The cell adds a new poly-A tail to the mRNA.
C)
The mRNA attaches to a ribosome and is translated, but more slowly.
D)
The molecule is digested by enzymes because it is not protected at the end.
end.
Use
this model of a eukaryotic transcript to answer the following question(s).
E
= exon and I = intron
UTR E1 I1 E2 I2 E3 I3 E4 UTR
28)
Which components of the previous molecule will also be found in mRNA in the
cytosol?
A)
UTR I1 I2 I3 UTR
UTR I1 I2 I3 UTR
B)
E1 E2 E3 E4
E1 E2 E3 E4
C)
UTR E1 E2 E3 E4 UTR
UTR E1 E2 E3 E4 UTR
D)
E1 I1 E2 I2 E3 I3 E4
E1 I1 E2 I2 E3 I3 E4
29)
Which one of the following statements about RNA processing is true?
A)
Exons are cut out before mRNA leaves the nucleus.
B)
Ribozymes may function in RNA splicing.
C)
RNA splicing can be catalyzed by tRNA.
D)
A primary transcript is often much shorter than the final RNA molecule that
leaves the nucleus.
30)
A primary transcript in the nucleus of a eukaryotic cell is _____ the
functional mRNA, while a primary transcript in a prokaryotic cell is _____ the
functional mRNA.
A)
the same size as; smaller than
B)
larger than; the same size as
C)
larger than; smaller than
D)
the same size as; larger than
31)
A particular triplet of bases in the coding sequence of DNA is AAA. The
anticodon on the tRNA that binds the mRNA codon is _____.
A)
TTT
B)
UUA
C)
UUU
D)
AAA
32)
Accuracy in the translation of mRNA into the primary structure of a polypeptide
depends on specificity in the _____.
A)
binding of ribosomes to mRNA
B)
binding of the anticodon to small subunit of the ribosome
C)
attachment of amino acids to rRNAs
D)
binding of the anticodon to the codon and the attachment of amino acids to
tRNAs
33)
A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches
a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine.
The consequence of this for the cell will be that _____.
A)
none of the proteins in the cell will contain phenylalanine
B)
proteins in the cell will include lysine instead of phenylalanine at amino acid
positions specified by the codon UUU
C)
the cell will compensate for the defect by attaching phenylalanine to tRNAs
with lysine-specifying anticodons
D)
the ribosome will skip a codon every time a UUU is encountered
34)
There are sixty-one mRNA codons that specify an amino acid, but only forty-five
tRNAs. This is best explained by the fact that _____.
A)
some tRNAs have anticodons that recognize four or more different codons
B)
the rules for base pairing between the third base of a codon and tRNA are
flexible
C)
many codons are never used, so the tRNAs that recognize them are dispensable
D)
the DNA codes for all sixty-one tRNAs, but some are then destroyed
35)
Which of the following is the first event to take place in translation in
eukaryotes?
A)
base pairing of activated methionine-tRNA to AUG of the messenger RNA
B)
binding of the larger ribosomal subunit to smaller ribosomal subunits
C)
covalent bonding between the first two amino acids
D)
the small subunit of the ribosome recognizes and attaches to the cap of mRNA
cap of mRNA
36)
A signal peptide _____.
A)
directs an mRNA molecule into the cisternal space of the ER
B)
terminates translation of messenger RNA
C)
helps target a protein to the ER
D)
signals the initiation of transcription
37)
The release factor (RF) _____.
A)
binds to the stop codon in the A site in place of a tRNA
B)
releases the amino acid from its tRNA to allow the amino acid to form a peptide
bond
C)
supplies a source of energy for termination of translation
D)
releases the ribosome from the ER to allow polypeptides into the cytosol
Use
the following information to answer the question(s) below.
A
part of an mRNA molecule with the following sequence is being read by a
ribosome: CCG-ACG (mRNA). The following charged transfer
RNA molecules (with their anticodons shown in the to direction) are available. Two of them can
correctly match the mRNA so that a dipeptide can form.
CCG-ACG (mRNA). The following charged transfer
RNA molecules (with their anticodons shown in the to direction) are available. Two of them can
correctly match the mRNA so that a dipeptide can form.|
tRNA Anticodon
|
Amino Acid
|
|
GGC
CGU
UGC
CCG
ACG
CGG
|
Proline
Alanine
Threonine
Glycine
Cysteine
Alanine
|
38)
The dipeptide that will form will be _____.
A)
cysteine-alanine
B)
proline-threonine
C)
glycine-cysteine
D)
alanine-alanine
39)
The anticodon loop of the first tRNA that will complement this mRNA is
A)
GGC
GGC
B)
GGC
GGC
C)
UGC
UGC
D)
UGC
UGC
40)
What type of bonding is responsible for maintaining the shape of the tRNA
molecule shown in the figure above?
A)
ionic bonding between phosphates
B)
hydrogen bonding between base pairs
C)
van der Waals interactions between hydrogen atoms
D)
peptide bonding between amino acids
41)
The figure above represents tRNA that recognizes and binds a particular amino
acid (in this instance, phenylalanine). Which codon on the mRNA strand codes
for this amino acid?
A)
UGG
B)
GUG
C)
GUA
D)
UUC
42)
The tRNA shown in the figure above has its end projecting beyond its end. What will occur at this end?
end projecting beyond its end. What will occur at this end?
A)
The amino acid binds covalently.
B)
The excess nucleotides (ACCA) will be cleaved off at the ribosome.
C)
The small and large subunits of the ribosome will attach to it.
D)
The cap of the mRNA will become covalently bound.
cap of the mRNA will become covalently bound.
43)
What must occur before a newly made polypeptide is secreted from a cell?
A)
It must be translated by a ribosome that remains free within the cytosol.
B)
Its signal sequence must target it to the ER, after which it goes to the Golgi.
C)
Its signal sequence must be cleaved off before the polypeptide can enter the
ER.
D)
Its signal sequence must target it to the plasma membrane, where it causes
exocytosis.
44)
Translation requires _____.
A)
mRNA, tRNA, DNA, and rRNA
B)
mRNA, DNA, and rRNA
C)
mRNA, tRNA, and rRNA
D)
mRNA, tRNA, and DNA
45)
During elongation, which site in the ribosome represents the location where a
codon is being read?
A)
E site
B)
P site
C) A site
D)
the small ribosomal subunit
46)
Once a peptide has been formed between the amino acid attached to the tRNA in
the P site and the amino acid associated with the tRNA in the A site, what
occurs next?
A)
translocation
B)
reading of the next codon of mRNA
C)
initiation
D)
The codon-anticodon hydrogen bonds holding the tRNA in the A site are broken.
47)
Which one of the following, if missing, would usually prevent translation from
starting?
A)
exon
B)
cap
cap
C)
AUG codon
D)
poly-A tail
48)
Put the following events of elongation in prokaryotic translation in chronological
order.
1. Binding
of mRNA with small ribosomal subunit
2. Recognition
of initiation codon
3. Complementary
base pairing between initiator codon and anticodon of initiator tRNA
4. Base
pairing of the mRNA codon following the initiator codon with its complementary
tRNA
5. Attachment
of the large subunit
A)
1, 2, 3, 4, 5
B)
2, 1, 4, 3, 5
C)
5, 4, 3, 2, 1
D)
1, 2, 3, 5, 4
49)
How does termination of translation take place?
A)
The end of the mRNA molecule is reached.
B)
A stop codon is reached.
C)
The cap is reached.
cap is reached.
D)
The poly-A tail is reached.
50)
Post-translational modifications of proteins may include the _____.
A)
removal of introns
B)
addition of a 5’ cap
C)
addition of a poly-A tail
D)
addition of carbohydrates to form a glycoprotein
51)
Which of the following statements is true about protein synthesis in
prokaryotes?
A)
Extensive RNA processing is required before prokaryotic transcripts can be
translated.
B)
Translation can begin while transcription is still in progress.
C)
Prokaryotic cells have complicated mechanisms for targeting proteins to the
appropriate cellular organelles.
D)
Unlike eukaryotes, prokaryotes require no initiation or elongation factors.
52)
Which of the following types of mutation, resulting in an error in the mRNA
just after the AUG start of translation, is likely to have the most serious
effect on the polypeptide product?
A)
a deletion of a codon
B)
a deletion of two nucleotides
C)
a substitution of the third nucleotide in an ACC codon
D)
a substitution of the first nucleotide of a GGG codon
53)
A nonsense mutation in a gene _____.
A)
changes an amino acid in the encoded protein
B)
has no effect on the amino acid sequence of the encoded protein
C)
introduces a premature stop codon into the mRNA
D)
alters the reading frame of the mRNA
54)
Which of the following DNA mutations is most likely to damage the protein it
specifies?
A)
a base-pair deletion
B)
an addition of three nucleotides
C)
a substitution in the last base of a codon
D)
a codon deletion
55)
The most commonly occurring mutation in people with cystic fibrosis is a
deletion of a single codon. This results in _____.
A)
a base-pair substitution
B)
a frameshift mutation
C)
a polypeptide missing an amino acid
D)
a nonsense mutation
56)
Of the following, which is the most current description of a gene?
A)
a unit of heredity that causes formation of a phenotypic characteristic
B)
a DNA subunit that codes for a single complete protein
C)
a DNA sequence that is expressed to form a functional product: either RNA or
polypeptide
D)
a discrete unit of hereditary information that consists of a sequence of amino
acids
57)
How might a single base substitution in the sequence of a gene affect the amino
acid sequence of a protein encoded by the gene, and why?
A)
Only a single amino acid could change, because the reading frame is unaffected.
B)
The amino acid sequence would be substantially altered, because the reading
frame would change with a single base substitution.
C)
All amino acids following the substitution would be affected, because the
reading frame would be shifted.
D)
It is not possible for a single base substitution to affect protein structure,
because each codon is three bases long.
58)
An original section of DNA has the base sequence AGCGTTACCGT. A mutation in
this DNA strand results in the base sequence AGGCGTTACCGT. This change
represents _____.
A)
a missense mutation
B)
a point mutation
C)
a silent mutation
D)
frameshift mutation
59)
A single base substitution mutation is least likely to be deleterious when the
base change results in _____.
A)
a stop codon
B)
a codon that specifies the same amino acid as the original codon
C)
an amino acid substitution that alters the tertiary structure of the protein
D)
an amino acid substitution at the active site of an enzyme
60)
Rank the following one-base point mutations (from most likely to least likely)
with respect to their likelihood of affecting the structure of the
corresponding polypeptide.
1. insertion
mutation deep within an intron
2. substitution
mutation at the third position of an exonic codon
3. substitution
mutation at the second position of an exonic codon
4. deletion
mutation within the first exon of the gene
A)
1, 2, 3, 4
B)
4, 3, 2, 1
C)
2, 1, 4, 3
D)
3, 1, 4, 2
Campbell Biology, 10e (Reece)
Chapter 18
Regulation of Gene Expression
1)
Which of the following is a protein produced by a regulatory gene?
A)
operon
B)
inducer
C)
promoter
D)
repressor
2)
A lack of which molecule would result in a cell's inability to "turn
off" genes?
A)
operon
B)
inducer
C)
promoter
D)
corepressor
3)
Which of the following, when taken up by a cell, binds to a repressor so that
the repressor no longer binds to the operator?
A)
inducer
B)
promoter
C)
repressor
D)
corepressor
4)
Most repressor proteins are allosteric. Which of the following binds with the
repressor to alter its conformation?
A)
inducer
B)
promoter
C)
transcription factor
D)
cAMP
5)
A mutation that inactivates a regulatory gene of a repressible operon in an E.
coli cell would result in _____.
A)
continuous transcription of the structural gene controlled by that regulator
B)
complete inhibition of transcription of the structural gene controlled by that
regulator
C)
irreversible binding of the repressor to the operator
D)
continuous translation of the mRNA because of alteration of its structure
6)
The lactose operon is likely to be transcribed when _____.
A)
there is more glucose in the cell than lactose
B)
there is glucose but no lactose in the cell
C)
the cyclic AMP and lactose levels are both high within the cell
D)
the cAMP level is high and the lactose level is low
7)
Transcription of structural genes in an inducible operon _____.
A)
occurs continuously in the cell
B)
starts when the pathway's substrate is present
C)
starts when the pathway's product is present
D)
stops when the pathway's product is present
8)
For a repressible operon to be transcribed, which of the following must occur?
A)
A corepressor must be present.
B)
RNA polymerase and the active repressor must be present.
C)
RNA polymerase must bind to the promoter, and the repressor must be inactive.
D)
RNA polymerase must not occupy the promoter, and the repressor must be
inactive.
9)
Altering patterns of gene expression in prokaryotes would most likely serve an
organism's survival by _____.
A)
organizing gene expression, so that genes are expressed in a given order
B)
allowing each gene to be expressed an equal number of times
C)
allowing an organism to adjust to changes in environmental conditions
D)
allowing environmental changes to alter a prokaryote's genome
10)
In positive control of several sugar-metabolism-related operons, the catabolite
activator protein (CAP) binds to DNA to stimulate transcription. What causes an
increase in CAP activity in stimulating transcription?
A)
an increase in glucose and an increase in cAMP
B)
a decrease in glucose and an increase in cAMP
C)
an increase in glucose and a decrease in cAMP
D)
a decrease in glucose and a decrease in the repressor
11)
There is a mutation in the repressor that results in a molecule known as a
super-repressor because it represses the lac operon permanently. Which
of these would characterize such a mutant?
A)
It cannot bind to the operator.
B)
It cannot make a functional repressor.
C)
It cannot bind to the inducer.
D)
It makes a repressor that binds CAP.
Use
this information to answer the question(s) below.
Suppose
an experimenter becomes proficient with a technique that allows her to move DNA
sequences within a prokaryotic genome.
12)
If she moves the promoter for the lac operon to the region between the
beta galactosidase (lacZ) gene and the permease (lacY) gene,
which of the following would be likely?
A)
The three structural genes will be expressed normally.
B)
RNA polymerase will no longer transcribe permease.
C)
The operon will still transcribe the lacZ and lacY genes, but the
mRNA will not be translated.
D)
Beta galactosidase will not be produced.
13)
If she moves the operator to the far end of the operon, past the transacetylase
(lacA) gene, which of the following would likely occur when the cell is
exposed to lactose?
A)
The inducer will no longer bind to the repressor.
B)
The repressor will no longer bind to the operator.
C)
The operon will never be transcribed.
D)
The structural genes will be transcribed continuously.
14)
If she moves the repressor gene (lacI), along with its promoter, to a
position at some several thousand base pairs away from its normal position, we
would expect the _____.
A)
repressor will no longer bind to the operator
B)
repressor will no longer bind to the inducer
C)
lac operon will be expressed continuously
D)
lac operon will function normally
15)
What would occur if the repressor of an inducible operon were mutated so that
it could not bind the operator?
A)
irreversible binding of the repressor to the promoter
B)
reduced transcription of the operon's genes
C)
continuous transcription of the operon's genes
D)
overproduction of catabolite activator protein (CAP)
16)
According to the lac operon model proposed by Jacob and Monod, what is
predicted to occur if the operator is removed from the operon?
A)
The lac operon would be transcribed continuously.
B)
Only lacZ would be transcribed.
C)
Only lacY would be transcribed.
D)
Galactosidase permease would be produced, but would be incapable of
transporting lactose.
17)
The trp repressor blocks transcription of the trp operon when the
repressor _____.
A)
binds to the inducer
B)
binds to tryptophan
C)
is not bound to tryptophan
D)
is not bound to the operator
18)
Extracellular glucose inhibits transcription of the lac operon by _____.
A)
strengthening the binding of the repressor to the operator
B)
weakening the binding of the repressor to the operator
C)
inhibiting RNA polymerase from opening the strands of DNA to initiate
transcription
D)
reducing the levels of intracellular cAMP
19)
CAP is said to be responsible for positive regulation of the lac operon
because _____.
A)
CAP binds cAMP
B)
CAP binds to the CAP-binding site
C)
CAP prevents binding of the repressor to the operator
D)
CAP bound to the CAP-binding site increases the frequency of transcription
initiation
20)
Imagine that you've isolated a yeast mutant that contains histones resistant to
acetylation. What phenotype do you predict for this mutant?
A)
The mutant will grow rapidly.
B)
The mutant will require galactose for growth.
C)
The mutant will show low levels of gene expression.
D)
The mutant will show high levels of gene expression.
21)
The primary difference between enhancers and promoter-proximal elements is that
enhancers _____.
A)
are transcription factors; promoter-proximal elements are DNA sequences
B)
enhance transcription; promoter-proximal elements inhibit transcription
C)
are at considerable distances from the promoter; promoter-proximal elements are
close to the promoter
D)
are DNA sequences; promoter-proximal elements are proteins
22)
The reason for differences in the sets of proteins expressed in a nerve and a
pancreatic cell of the same individual is that nerve and pancreatic cells
contain different _____.
A)
genes
B)
regulatory sequences
C)
sets of regulatory proteins
D)
promoters
23)
Gene expression is often assayed by measuring the level of mRNA produced from a
gene. If one is interested in knowing the amount of a final active gene
product, a potential problem of this method is that it ignores the possibility
of _____.
A)
chromatin condensation control
B)
transcriptional control
C)
alternative splicing
D)
translational control
24)
Not long ago, it was believed that a count of the number of protein-coding
genes would provide a count of the number of proteins produced in any given
eukaryotic species. This is incorrect, largely due to the discovery of
widespread _____.
A)
chromatin condensation control
B)
transcriptional control
C)
alternative splicing
D)
translational control
25)
One way to detect alternative splicing of transcripts from a given gene is to
_____.
A)
compare the DNA sequence of the given gene to that of a similar gene in a
related organism
B)
measure the relative rates of transcription of the given gene compared to that
of a gene known to be constitutively spliced
C)
compare the sequences of different primary transcripts made from the given gene
D)
compare the sequences of different mRNAs made from the given gene
26)
Which of the following mechanisms is (are) used to coordinate the expression of
multiple, related genes in eukaryotic cells?
A)
Environmental signals enter the cell and bind directly to promoters.
B)
The genes share a single common enhancer, which allows appropriate activators
to turn on their transcription at the same time.
C)
The genes are organized into a large operon, allowing them to be coordinately
controlled as a single unit.
D)
A single repressor is able to turn off several related genes.
27)
DNA methylation and histone acetylation are examples of _____.
A)
genetic mutation
B)
chromosomal rearrangements
C)
epigenetic phenomena
D)
translocation
28)
In eukaryotes, general transcription factors _____
A)
bind to other proteins or to the TATA box
B)
inhibit RNA polymerase binding to the promoter and begin transcribing
C)
usually lead to a high level of transcription even without additional specific
transcription factors
D)
bind to sequences just after the start site of transcription
29)
Steroid hormones produce their effects in cells by _____.
A)
activating key enzymes in metabolic pathways
B)
activating translation of certain mRNAs
C)
promoting the degradation of specific mRNAs
D)
binding to intracellular receptors and promoting transcription of specific
genes
30)
Which of the following is most likely to have a small protein called ubiquitin
attached to it?
A)
a cyclin protein, that usually acts in G1, in a cell that is in G2
B)
a cell surface protein that requires transport from the ER
C)
an mRNA leaving the nucleus to be translated
D)
an mRNA produced by an egg cell that will be retained until after fertilization
Use
this information to answer the question(s) below.
A
researcher found a method she could use to manipulate and quantify
phosphorylation and methylation in embryonic cells in culture.
31)
In one set of experiments she succeeded in increasing acetlylation of histone
tails. Which of the following results would she most likely see?
A)
increased chromatin condensation
B)
decreased chromatin condensation
C)
decreased binding of transcription factors
D)
inactivation of the selected genes
32)
One of her colleagues suggested she try increased methylation of C nucleotides
in the DNA of promoters of a mammalian system. Which of the following results
would she most likely see?
A)
decreased chromatin condensation
B)
activation of histone tails for enzymatic function
C)
higher levels of transcription of certain genes
D)
inactivation of the selected genes
33)
Which method is utilized by eukaryotes to control their gene expression that is
NOT used in bacteria?
A)
control of chromatin remodeling
B)
control of RNA splicing
C)
transcriptional control
D)
control of both RNA splicing and chromatin remodeling
34)
The phenomenon in which RNA molecules in a cell are destroyed if they have a
sequence complementary to an introduced double-stranded RNA is called _____.
A)
RNA interference
B)
RNA obstruction
C)
RNA blocking
D)
RNA disposal
35)
At the beginning of this century there was a general announcement regarding the
sequencing of the human genome and the genomes of many other multicellular
eukaryotes. Many people were surprised that the number of protein-coding
sequences was much smaller than they had expected. Which of the following could
account for much of the DNA that is not coding for proteins?
A)
DNA that consists of histone coding sequences
B)
DNA that is translated directly without being transcribed
C)
non-protein-coding DNA that is transcribed into several kinds of small RNAs
with biological function
D)
non-protein-coding DNA that serves as binding sites for reverse transcriptase
36)
Among the newly discovered small noncoding RNAs, one type reestablishes
methylation patterns during gamete formation and blocks expression of some
transposons. These are known as _____.
A)
miRNA
B)
piRNA
C)
snRNA
D)
siRNA
37)
Which of the following best describes siRNA?
A)
a double-stranded RNA, one of whose strands can complement and inactivate a
sequence of mRNA
B)
a single-stranded RNA that can, where it has internal complementary base pairs,
fold into cloverleaf patterns
C)
a double-stranded RNA that is formed by cleavage of hairpin loops in a larger
precursor
D)
a portion of rRNA that allows it to bind to several ribosomal proteins in
forming large or small subunits
Use
this information to answer the question(s) below.
A
researcher introduces double-stranded RNA into a culture of mammalian cells and
can identify its location or that of its smaller subsections experimentally,
using a fluorescent probe.
38)
Some time later, she finds that the introduced strand separates into
single-stranded RNAs, one of which is degraded. What does this enable the
remaining strand to do?
A)
attach to histones in the chromatin
B)
bind to complementary regions of target mRNAs
C)
activate other siRNAs in the cell
D)
bind to noncomplementary RNA sequences
39)
When she finds that the introduced strand separates into single-stranded RNAs,
what other evidence of this single-stranded RNA piece's activity can she find?
A)
She can measure the degradation rate of the remaining single strand.
B)
The rate of accumulation of the polypeptide encoded by the target mRNA is
reduced.
C)
The amount of miRNA is multiplied by its replication.
D)
The cell's translation ability is entirely shut down.
40)
The fact that plants can be cloned from somatic cells demonstrates that _____.
A)
differentiated cells retain all the genes of the zygote
B)
genes are lost during differentiation
C)
the differentiated state is normally very unstable
D)
differentiation does not occur in plants
41)
Your brother has just purchased a new plastic model airplane. He places all the
parts on the table in approximately the positions in which they will be located
when the model is complete. His actions are analogous to which process in
development?
A)
morphogenesis
B)
determination
C)
differentiation
D)
pattern formation
42)
The product of the bicoid gene in Drosophila provides essential
information about _____.
A)
the dorsal-ventral axis
B)
the left-right axis
C)
segmentation
D)
the anterior-posterior axis
43)
If a Drosophila female has a homozygous mutation for a maternal effect
gene, _____.
A)
she will not develop past the early embryonic stage
B)
all of her offspring will show the mutant phenotype, regardless of their
genotype
C)
only her male offspring will show the mutant phenotype
D)
only her female offspring will show the mutant phenotype
44)
Mutations in which of the following genes lead to transformations in the
identity of entire body parts?
A)
segmentation genes
B)
egg-polarity genes
C)
homeotic genes
D)
inducers
45)
Which of the following are maternal effect genes that control the orientation
of the egg and thus the Drosophila embryo?
A)
homeotic genes
B)
segmentation genes
C)
egg-polarity genes
D)
morphogens
46)
The bicoid gene product is normally localized to the anterior end of the
embryo. If large amounts of the product were injected into the posterior end as
well, which of the following would occur?
A)
The embryo would grow extra wings and legs.
B)
The embryo would probably show no anterior development and die.
C)
Anterior structures would form in both ends of the embryo.
D)
The embryo would develop normally.
47)
In colorectal cancer, several genes must be mutated for a cell to develop into
a cancer cell. Which of the following kinds of genes would you expect to be
mutated?
A)
genes coding for enzymes that act in the colon
B)
genes involved in control of the cell cycle
C)
genes that are especially susceptible to mutation
D)
genes of the bacteria, which are abundant in the colon
48)
A cell is considered to be differentiated when it _____.
A)
replicates by the process of mitosis
B)
loses connections to the surrounding cells
C)
produces proteins specific to a particular cell type
D)
appears to be different from the surrounding cells
49)
When the Bicoid protein is expressed in Drosophila, the embryo is still
syncytial (divisions between cells are not yet fully developed). This
information helps to explain which observation by Nüsslein-Volhard and
Wieschaus?
A)
mRNA from the egg is translated into the Bicoid protein.
B)
Bicoid protein diffuses throughout the embryo in a concentration gradient.
C)
Bicoid protein serves as a transcription regulator.
D)
Bicoid protein determines the dorsoventral axis of the embryo.
50)
The protein of the bicoid gene in Drosophila determines the _____
of the embryo.
A)
anterior-posterior axis
B)
anterior-lateral axis
C)
posterior-dorsal axis
D)
posterior-ventral axis
51)
Which of the following types of mutation would convert a proto-oncogene into an
oncogene?
A)
a mutation that blocks transcription of the proto-oncogene
B)
a mutation that creates an unstable proto-oncogene mRNA
C)
a mutation that greatly increases the amount of the proto-oncogene protein
D)
a deletion of most of the proto-oncogene coding sequence
52)
Proto-oncogenes _____.
A)
normally suppress tumor growth
B)
are produced by somatic mutations induced by carcinogenic substances
C)
stimulate normal cell growth and division
D)
are underexpressed in cancer cells
53)
The product of the p53 gene _____.
A)
inhibits the cell cycle
B)
slows down the rate of DNA replication by interfering with the binding of DNA
polymerase
C)
causes cells to reduce expression of genes involved in DNA repair
D)
allows cells to pass on mutations due to DNA damage
54)
Tumor-suppressor genes _____.
A)
are frequently overexpressed in cancerous cells
B)
are cancer-causing genes introduced into cells by viruses
C)
encode proteins that help prevent uncontrolled cell growth
D)
often encode proteins that stimulate the cell cycle
55)
BRCA1 and BRCA2 are considered to be tumor-suppressor genes
because _____.
A)
their normal products participate in repair of DNA damage
B)
the mutant forms of either one of these prevent breast cancer
C)
the normal genes make estrogen receptors
D)
they block penetration of breast cells by chemical carcinogens
56)
Forms of the Ras protein found in tumors usually cause which of the following?
A)
DNA replication to stop
B)
cell-to-cell adhesion to be nonfunctional
C)
cell division to cease
D)
excessive cell division
57)
A genetic test to detect predisposition to cancer would likely examine the APC
gene for involvement in which type(s) of cancer?
A)
colorectal only
B)
lung and breast
C)
lung only
D)
lung and prostate
58)
In colorectal cancer, several genes must be mutated for a cell to develop into
a cancer cell. Which of the following kinds of genes would you expect to be
mutated?
A)
genes coding for enzymes that act in the colon
B)
genes involved in control of the cell cycle
C)
genes that are especially susceptible to mutation
D)
genes of the bacteria, which are abundant in the colon
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