AP Heredity Study Guide

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ap heredity study guide

 

 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
Pea plants were particularly well suited for use in Mendel’s breeding experiments for all of the following reasons except that
a.
peas show easily observed variations in a number of characters, such as pea shape and flower color.
b.
it is possible to completely control matings between different pea plants.
c.
it is possible to obtain large numbers of progeny from any given cross.
d.
peas have an unusually long generation time.
e.
many of the observable characters that vary in pea plants are controlled by single genes.
 2.
A plant with purple flowers is allowed to self-pollinate. Generation after generation, it produces purple flowers. This is an example of
a.
hybridization.
b.
incomplete dominance.
c.
true-breeding.
d.
the law of segregation.
e.
polygenetics.
 3.
Which of the following statements about Mendel’s breeding experiments is correct?
a.
None of the parental (P) plants were true-breeding.
b.
All of the F2 progeny showed a phenotype that was intermediate between the two parental (P) phenotypes.
c.
Half of the F1 progeny had the same phenotype as one of the parental (P) plants, and the other half had the same phenotype as the other parent.
d.
All of the F1 progeny resembled one of the parental (P) plants, but only some of the F2 progeny did.
e.
none of the above
 4.
What is the difference between a monohybrid cross and a dihybrid cross?
a.
A monohybrid cross involves a single parent, whereas a dihybrid cross involves two parents.
b.
A monohybrid cross produces a single progeny, whereas a dihybrid cross produces two progeny.
c.
A monohybrid cross involves organisms that are heterozygous for a single character, whereas a dihybrid cross involves organisms that are heterozygous for two characters.
d.
A monohybrid cross is performed only once, whereas a dihybrid cross is performed twice.
e.
A monohybrid cross results in a 9:3:3:1 ratio whereas a dihybrid cross gives a 3:1 ratio.
 5.
A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates
a.
the blending model of genetics.
b.
true-breeding.
c.
dominance.
d.
a dihybrid cross.
e.
the mistakes made by Mendel.
 6.
The F1 offspring of Mendel’s classic pea cross always looked like one of the two parental varieties because
a.
one allele was completely dominant over another.
b.
each allele affected phenotypic expression.
c.
the traits blended together during fertilization.
d.
no genes interacted to produce the parental phenotype.
e.
different genes interacted to produce the parental phenotype.
 7.
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 than do dominant ones.
d.
Genes are composed of DNA.
e.
An organism that is homozygous for many recessive traits is at a disadvantage.
 8.
Which of the following is (are) true for alleles?
a.
They can be identical or different for any given gene in a somatic cell.
b.
They can be dominant or recessive.
c.
They can represent alternative forms of a gene.
d.
Only A and B are correct.
e.
A, B, and C are correct.
 9.
What is genetic cross between an individual showing a dominant phenotype (but of unknown genotype) and a homozygous recessive individual called?
a.
a self-cross
b.
a testcross
c.
a hybrid cross
d.
an F1 cross
e.
a dihybrid cross
 10.
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?
a.
4
b.
8
c.
16
d.
32
e.
64
 11.
Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests
a.
that the parents were true-breeding for contrasting traits.
b.
incomplete dominance.
c.
that a blending of traits has occurred.
d.
that the parents were both heterozygous.
e.
that each offspring has the same alleles.
 12.
Two characters that appear in a 9:3:3:1 ratio in the F2 generation should have which of the following properties?
a.
Each of the characters is controlled by a single gene.
b.
The genes controlling the characters obey the law of independent assortment.
c.
Each of the genes controlling the characters has two alleles.
d.
Only A and C are correct.
e.
A, B, and C are correct.
 13.
A 9:3:3:1 phenotypic ratio is characteristic of which of the following?
a.
a monohybrid cross
b.
a dihybrid cross
c.
a trihybrid cross
d.
linked genes
e.
both A and D
 14.
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.
HT
b.
Hh
c.
HhTt
d.
T
e.
tt
 15.
It was important that Mendel examined not just the F1 generation in his breeding experiments, but the F2 generation as well, because
a.
he obtained very few F1 progeny, making statistical analysis difficult.
b.
parental traits that were not observed in the F1 reappeared in the F2, suggesting that the traits did not truly disappear in the F1.
c.
analysis of the F1 progeny would have allowed him to discover the law of segregation, but not the law of independent assortment.
d.
the dominant phenotypes were visible in the F2 generation, but not in the F1.
e.
all of the above
 16.
When crossing a homozygous recessive with a heterozygote, what is the chance of getting an offspring with the homozygous recessive phenotype?
a.
0%
b.
25%
c.
50%
d.
75%
e.
100%

Use the diagram and description below to answer the following question.

In a particular plant, leaf color is controlled by gene D. Plants with the dominant 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 this cross is diagrammed in the Punnett square shown below, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square.

nar001-1.jpg

 17.
Which of the boxes marked 1-4 correspond to plants with dark leaves?
a.
1 only
b.
1 and 2
c.
2 and 3
d.
4 only
e.
1, 2, and 3
 18.
Which of the boxes correspond to plants with a heterozygous genotype?
a.
1
b.
1 and 2
c.
1, 2, and 3
d.
2 and 3
e.
2, 3, and 4
 19.
Which of the plants will be true-breeding?
a.
1 and 4
b.
2 and 3
c.
1-4
d.
1 only
e.
none
 20.
P = purple, pp = white. The offspring of a cross between two heterozygous purple-flowering plants (Pp Pp) results in
a.
all purple-flowered plants.
b.
purple-flowered plants and white-flowered plants.
c.
two types of white-flowered plants: PP and Pp.
d.
all white-flowered plants.
e.
all pink-flowered plants.
 21.
Mendel accounted for the observation that traits which 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.
the traits were lost in the F1 due to blending of the parental traits.
e.
members of the F1 generation had only one allele for each character, but members of the F2 had two alleles for each character.
 22.
What are Punnett squares used for?
a.
predicting the result of genetic crosses between organisms of known genotypes
b.
determining the DNA sequence of a given gene
c.
identifying the gene locus where allelic variations are possible
d.
testing for the presence of the recessive allele
e.
more than one of the above
 23.
Which of the following is false, regarding the law of segregation?
a.
It states that each of two alleles for a given trait segregate into different gametes.
b.
It can be explained by the segregation of homologous chromosomes during meiosis.
c.
It can account for the 3:1 ratio seen in the F2 generation of Mendel’s crosses.
d.
It can be used to predict the likelihood of transmission of certain genetic diseases within families.
e.
It is a method that can be used to determine the number of chromosomes in a plant.
 24.
The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment means that
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.
e.
the formation of gametes in plants occurs by mitosis only.
 25.
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 the cross BbTt BBtt will have black fur and long tails?
a.
1/16
b.
3/16
c.
3/8
d.
1/2
e.
9/16
 26.
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.
1/2
b.
1/4
c.
0
d.
1
e.
1/6
 27.
A couple has three children, all of whom have brown eyes and blond hair. Both parents are homozygous for brown eyes (BB) but one is a blond (rr) and the other is a redhead (Rr). What is the probability that their next child will be a brown-eyed redhead?
a.
1/16
b.
1/8
c.
1/4
d.
1/2
e.
1
 28.
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. If 1,000 F2 offspring resulted from the cross, approximately how many of them would you expect to have red, terminal flowers? (Assume independent assortment).
a.
65
b.
190
c.
250
d.
565
e.
750
 29.
In a cross AaBbCc AaBbCc, what is the probability of producing the genotype AABBCC?
a.
1/4
b.
1/8
c.
1/16
d.
1/32
e.
1/64
 30.
Given the parents AABBCc AabbCc, assume simple dominance and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent?
a.
1/4
b.
1/8
c.
3/4
d.
3/8
e.
1
 31.
A 1:2:1 phenotypic ratio in the F2 generation of a monohybrid cross is a sign of
a.
complete dominance.
b.
multiple alleles.
c.
incomplete dominance.
d.
polygenic inheritance.
e.
pleiotropy.

Refer to the result below to answer the following questions.

A tall plant is crossed with a short plant, and the progeny are all intermediate in size between the two parental plants.

 32.
This could be an example of
a.
incomplete dominance.
b.
polygenic inheritance.
c.
complete dominance.
d.
A and B
e.
B and C
 33.
If the intermediate F1 progeny were allowed to self-pollinate, and the F2 progeny were also intermediate in size, but following a normal distribution, this would suggest
a.
incomplete dominance.
b.
polygenic inheritance.
c.
complete dominance.
d.
a strong environmental influence.
e.
codominance.
 34.
If the intermediate F1 progeny were allowed to self-pollinate, and 25% of the F2 progeny were tall, 50% were intermediate in size, and 25% were short, this would suggest
a.
incomplete dominance.
b.
polygenic inheritance.
c.
complete dominance.
d.
pleiotropy.
e.
multifactorial inheritance.
 35.
In snapdragons, heterozygotes have pink flowers, whereas homozygotes have red or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers?
a.
0%
b.
25%
c.
50%
d.
75%
e.
100%
 36.
Tallness (T) is dominant to dwarfness (t), while red (R) flower color is dominant to white (r). The heterozygous condition results in pink (Rr) flower color. A dwarf, red snapdragon is crossed with a plant homozygous for tallness and white flowers. What are the genotype and phenotype of the F1 individuals?
a.
ttRr-dwarf and pink
b.
ttrr-dwarf and white
c.
TtRr-tall and red
d.
TtRr-tall and pink
e.
TTRR-tall and red
 37.
Skin color in a fish is inherited via a single gene with four different alleles. How many different types of gametes would be possible in this system?
a.
1
b.
2
c.
4
d.
8
e.
16
 38.
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
e.
The answer cannot be determined from the information provided.
 39.
The relationship between genes S and N is an example of
a.
incomplete dominance.
b.
epistasis.
c.
complete dominance.
d.
pleiotropy.
e.
codominance.
 40.
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.
all spineless progeny
e.
It is impossible to determine the phenotypes of the progeny.
 41.
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.
1 sharp-spined : 1 dull-spined
e.
9 sharp-spined : 3 dull-spined : 4 spineless

Use the information below to answer the following questions.

Feather color in budgies is determined by two different genes Y and B. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white.

 42.
A blue budgie is crossed with a white budgie. Which of the following results is not possible?
a.
green offspring
b.
yellow offspring
c.
blue offspring
d.
A and B
e.
A, B, and C
 43.
Two blue budgies were crossed. Over the years, they produced 22 offspring, 5 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
e.
yyBb and yybb
 44.

Three babies were mixed up in a hospital. After consideration of the data below, which of the following represent the correct baby and parent combinations?

Couple #
Blood Groups
I
A and A
II
A and B
III
B and O
Baby #
Blood Groups
1
B
2
O
3
AB
a.
I-3, II-1, III-2
b.
I-1, II-3, III-2
c.
I-2, II-3, III-1
d.
I-2, II-1, III-3
e.
I-3, II-2, III-1

Use the following information to answer the questions below.

A woman who has blood type A, has a daughter who is type O positive and a son who is type B negative. Rh positive is a simple dominant trait over Rh negative.

 45.
Which of the following is a possible genotype for the son?
a.
IBIB
b.
IBIA
c.
ii
d.
IBi
e.
IAIA
 46.
Which of the following is a possible genotype for the mother?
a.
IAIA
b.
IBIB
c.
ii
d.
IAi
e.
IAIB
 47.
Which of the following is a possible phenotype for the father?
a.
A
b.
O
c.
B
d.
AB
e.
impossible to determine
 48.
Which of the following is the probable genotype for the mother?
a.
IAIARR
b.
IAIARr
c.
IAirr
d.
IAiRr
e.
IAiRR
 49.
Which of the following is a possible phenotype of the father?
a.
A negative
b.
O negative
c.
B positive
d.
A positive
e.
O positive
 50.
What is the chromosomal system for determining sex in mammals?
a.
A
b.
B
c.
C
d.
D
e.
E
 51.
What is the chromosomal system for sex determination in grasshoppers and certain other insects?
a.
A
b.
B
c.
C
d.
D
e.
E
 52.
What is the chromosomal system for sex determination in birds?
a.
A
b.
B
c.
C
d.
D
e.
E
 53.
What is the chromosomal system of sex determination in most species of ants and bees?
a.
A
b.
B
c.
C
d.
D
e.
E

Use the terms listed below to answer the following questions. Each term may be used once, more than once, or not at all.

A. incomplete dominance
B. multiple alleles
C. pleiotropy
D. epistasis
 54.
the ability of a single gene to have multiple phenotypic effects
a.
A
b.
B
c.
C
d.
D
 55.
the ABO blood group system
a.
A
b.
B
c.
C
d.
D
 56.
the phenotype of the heterozygote differs from the phenotypes of both homozygotes
a.
A
b.
B
c.
C
d.
D
 57.
cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections
a.
A
b.
B
c.
C
d.
D
 58.
Which of the following is an example of polygenic inheritance?
a.
pink flowers in snapdragons
b.
the ABO blood groups in humans
c.
Huntington’s disease in humans
d.
white and purple flower color in peas
e.
skin pigmentation in humans
 59.
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
a.
environmental factors such as soil pH.
b.
the allele for blue hydrangea being completely dominant.
c.
the alleles being codominant.
d.
the fact that a mutation has occurred.
e.
acknowledging that multiple alleles are involved.

Use the information below to answer the following questions.

A woman and her spouse both show the normal phenotype for pigmentation, but both had one parent who was an albino. Albinism is an autosomal recessive trait.

 60.
What is the probability that their first child will be an albino?
a.
0
b.
1/4
c.
1/2
d.
3/4
e.
1
 61.
If their first two children have normal pigmentation, what is the probability that their third child will be an albino?
a.
0
b.
1/4
c.
1/2
d.
3/4
e.
1
 62.
Huntington’s disease is caused by a dominant allele. If one of your parents has the disease, what is the probability that you, too, will have the disease?
a.
1
b.
3/4
c.
1/2
d.
1/4
e.
0
 63.
A woman has six sons. The chance that her next child will be a daughter is
a.
1.
b.
0.
c.
1/2.
d.
1/6.
e.
5/6.

The pedigree chart below is for a family, some of whose members exhibit the recessive trait, wooly hair. Affected individuals are indicated by an open square or circle. Use the chart to answer the following questions.

nar007-1.jpg

 64.
What is the genotype of individual B-5?
a.
WW
b.
Ww
c.
ww
d.
WW or ww
e.
ww or Ww
 65.
What is the likelihood that the progeny of D-3 and D-4 will have wooly hair?
a.
0%
b.
25%
c.
50%
d.
75%
e.
100%
 66.
What is the probability that individual C-1 is Ww?
a.
3/4
b.
1/4
c.
2/4
d.
2/3
e.
1
 67.
People with sickle-cell trait
a.
are heterozygous for the sickle-cell allele.
b.
are usually healthy.
c.
have increased resistance to malaria.
d.
produce normal and abnormal hemoglobin.
e.
all of the above
 68.
When a disease is said to have a multifactorial basis, it means that
a.
many factors, both genetic and environmental, contribute to the disease.
b.
it is caused by a gene with a large number of alleles.
c.
it affects a large number of people.
d.
it has many different symptoms.
e.
it tends to skip a generation.
 69.
Which of the following terms is least related to the others?
a.
pedigree
b.
karyotype
c.
amniocentesis
d.
chorionic villus sampling
e.
epistasis

Use the answers below to answer the following questions. Each answer may be used once, more than once, or not at all.

A. Huntington’s disease
B. Tay-Sachs disease
C. phenylketonuria
D. cystic fibrosis
E. sickle-cell disease
 70.
Substitution of the “wrong” amino acid in the hemoglobin protein results in this disorder.
a.
A
b.
B
c.
C
d.
D
e.
E
 71.
Individuals with this disorder are unable to metabolize certain lipids, affecting proper brain development. Affected individuals die in early childhood.
a.
A
b.
B
c.
C
d.
D
e.
E
 72.
This is caused by a dominant single gene defect and generally does not appear until the individual is 35-45 years of age.
a.
A
b.
B
c.
C
d.
D
e.
E
 73.
Effects of this recessive disorder can be completely overcome by regulating the diet of the affected individual.
a.
A
b.
B
c.
C
d.
D
e.
E
 74.
This results from a defect in membrane proteins that normally function in chloride ion transport.
a.
A
b.
B
c.
C
d.
D
e.
E
 75.
Which of the following techniques involves the preparation of a karyotype?
a.
amniocentesis
b.
chorionic villus sampling
c.
fetoscopy
d.
A and B only
e.
A, B, and C
Media Activity Questions
 76.
All the offspring of a cross between a black-eyed MendAlien and an orange-eyed MendAlien have black eyes. This means that the allele for black eyes is ____ the allele for orange eyes.
a.
codominant to
b.
recessive to
c.
more aggressive than
d.
dominant to
e.
better than
 77.
What is the expected phenotypic ratio of a cross between two orange-eyed MendAliens?
a.
3 black-eyed:1 orange-eyed
b.
0 black-eyed:1 orange-eyed
c.
1 black-eyed:3 orange-eyed
d.
1 black-eyed:0 orange-eyed
e.
1 black-eyed:1 orange-eyed
 78.
Andalusian chickens with the genotype CBCB are black, those with the genotype CBCW are gray. What is the relationship between the CB and the CW alleles?
a.
CB is dominant to CW.
b.
CB is recessive to CW.
c.
CW is dominant to CB.
d.
The relationship is one of incomplete dominance.
e.
CB and CW are codominant.
 79.
Black eyes are dominant to orange eyes, and green skin is dominant to white skin. Sam, a MendAlien with black eyes and green skin, has a parent with orange eyes and white skin. Carole is MendAlien with orange eyes and white skin. If Sam and Carole were to mate, the predicted ratio of their offspring would be:
a.
1 black eyes, green skin: 1 black eyes, white skin: 1 orange eyes, green skin: 1 orange eyes, white skin
b.
3 black eyes, green skin: 3 black eyes, white skin: 9 orange eyes, green skin: 1 orange eyes, white skin
c.
1 black eyes, green skin: 3 black eyes, white skin: 3 orange eyes, green skin: 9 orange eyes, white skin
d.
9 black eyes, green skin: 3 black eyes, white skin: 3 orange eyes, green skin: 1 orange eyes, white skin
e.
There is insufficient information to determine Sam’s genotype.
 80.
All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is ____ to the allele for white flowers.
a.
dominant
b.
codominant
c.
pleiotropic
d.
incompletely dominant
e.
recessive
 81.
You conduct a dihybrid cross and then testcross the F1 generation. A ____ ratio would make you suspect that the genes are linked.
a.
3:1
b.
1:2:1
c.
1:1:1:1
d.
7:7:1:1
e.
9:3:3:1
 82.
The recombination frequency between gene A and gene B is 8.4%, the recombination frequency between gene A and gene C is 6.8%, and the recombination frequency between gene B and gene C is 15.2%. Which is the correct arrangement of these genes?
a.
ABC
b.
ACB
c.
BCA
d.
CAB
e.
CBA
 83.
Hypophosphatemia (vitamin D-resistant rickets) is inherited as a X-linked dominant disorder. An unaffected woman mates with a male with hypophosphatemia. What is the expected phenotypic ratio of their offspring?
a.
1 normal daughter: 1 daughter with hypophosphatemia
b.
1 normal daughter : 1 son with hypophosphatemia
c.
1 daughter with hypophosphatemia : 1 normal son
d.
2 normal daughters : 1 normal son : 1 son with hypophosphatemia
e.
3 normal daughters : 1 son with hypophosphatemia
 84.
The sex chromosome complements of both normal human and normal MendAlien males is
a.
XO.
b.
XX.
c.
XY.
d.
YY.
e.
YO.
 85.
Mutant tetraploid plants
a.
are usually sickly.
b.
are able to interbreed with their parents.
c.
have an odd number of chromosomes.
d.
are unable to breed with a diploid plant.
e.
are unable to self-fertilize.
 86.
Chromosomes and genes share all of the following characteristics except that
a.
they are both present in pairs in all diploid cells.
b.
they both undergo segregation during meiosis.
c.
their copy numbers in the cell decrease after meiosis, and increase during fertilization.
d.
they are both copied during the S phase of the cell cycle.
e.
they both pair up with their homologues during prophase of mitosis.
 87.
The improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics because
a.
it revealed new and unanticipated features of Mendel’s pea plant varieties.
b.
it allowed biologists to study meiosis and mitosis, revealing the parallels between the behaviors of genes and chromosomes.
c.
it allowed scientists to see the DNA present within chromosomes.
d.
it led to the discovery of mitochondria.
e.
All of the above are true.
 88.
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 involved gene was on the X chromosome.
b.
The involved gene was on the Y chromosome.
c.
The involved gene was on an autosome.
d.
Other male-specific factors influence eye color in flies.
e.
Other female-specific factors influence eye color in flies.
 89.
Which of the following statements is (are) true?
a.
The closer two genes are on a chromosome, the higher 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 50%.
c.
Two of the traits that Mendel studied-seed color and flower color-are linked on the same chromosome.
d.
Only B and C are correct.
e.
A, B, and C are correct.
 90.
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 linked.
b.
The two genes are unlinked.
c.
Recombination did not occur in the cell during meiosis.
d.
The testcross was improperly performed.
e.
Both of the characters are controlled by more than one gene.
 91.
New combinations of linked genes are due to which of the following?
a.
nondisjunction
b.
crossing over
c.
independent assortment
d.
mixing of sperm and egg
e.
both A and C
 92.
What does a frequency of recombination of 50% indicate?
a.
The two genes likely are 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.
e.
Independent assortment is hindered.

The following questions refer to the data and figures below.

CROSS I. Purebred lines of wild-type fruit flies (gray body and normal wings) are mated to flies with black bodies and vestigial wings.

nar010-1.jpg

F1 offspring all have a normal phenotype.

nar010-2.jpg

CROSS II. F1 flies are crossed with flies recessive for both traits (a testcross).

Resulting Offspring Normal Percentage
Gray body; normal wings
575
25.1
Black body; vestigial wings
571
24.9
Black body; normal wings
577
25.2
Gray body; vestigial wings
568
24.8

KEY:
A. CROSS I results give evidence supporting the statement.
B. CROSS I results give evidence against the statement.
C. CROSS II results give evidence supporting the statement.
D. CROSS II results give evidence against the statement.
E. Neither CROSS I nor CROSS II results support the statement.

 93.
Vestigial wings are a recessive trait.
a.
A
b.
B
c.
C
d.
D
e.
E
 94.
The genes for body color and wing shape are linked.
a.
A
b.
B
c.
C
d.
D
e.
E
 95.
An F1 cross should produce flies that will fall into a Mendelian 9:3:3:1 ratio.
a.
A
b.
B
c.
C
d.
D
e.
E
 96.
There are 25 centimorgans (map units) between the genes for body color and wing shape.
a.
A
b.
B
c.
C
d.
D
e.
E
 97.
A 0.1% frequency of recombination is observed
a.
only in sex chromosomes.
b.
only on genetic maps of viral chromosomes.
c.
on unlinked chromosomes.
d.
in any two genes on different chromosomes.
e.
in genes located very close to one another on the same chromosome.
 98.

The following is a map of four genes on a chromosome:

mc098-1.jpg
Between which two genes would you expect the highest frequency of recombination?

a.
A and W
b.
W and E
c.
E and G
d.
A and E
e.
A and G
 99.
The reason that linked genes are inherited together is that
a.
they are located on the same chromosome.
b.
the number of genes in a cell is greater than the number of chromosomes.
c.
chromosomes are unbreakable.
d.
alleles are paired.
e.
genes align that way during metaphase I.
 100.
What is the mechanism for the production of genetic recombinants?
a.
X inactivation
b.
methylation of cytosine
c.
crossing over and independent assortment
d.
nondisjunction
e.
deletions and duplications during meiosis
 101.
There is good evidence for linkage when
a.
two genes occur together in the same gamete.
b.
a gene is associated with a specific phenotype.
c.
two genes work together to control a specific characteristic.
d.
genes do not segregate independently during meiosis.
e.
two characteristics are caused by a single gene.

Refer to the figure below to answer the following questions.

nar011-1.jpg

 102.
In a series of mapping experiments, the recombination frequencies for four different linked genes of Drosophila were determined as shown in the figure. What is the order of these genes on a chromosome map?
a.
rb-cn-vg-b
b.
vg-b-rb-cn
c.
cn-rb-b-vg
d.
b-rb-cn-vg
e.
vg-cn-b-rb
 103.
Which of the following two genes are closest on a genetic map of Drosophila?
a.
b and vg
b.
vg and cn
c.
rb and cn
d.
cn and b
e.
b and rb
X, Y, and Z are three genes in Drosophila. The recombination frequencies for two of the three genes are shown below.

nar012-1.jpg
 104.
Genes X and Y could be
a.
located on different chromosomes.
b.
located very near to each other on the same chromosome.
c.
located far from each other on the same chromosome.
d.
both A and B
e.
both A and C
 105.
If the recombination frequency for Y and Z was found to be 50%, this would mean that
a.
genes X and Y are on the same chromosome.
b.
genes X and Y are on different chromosomes.
c.
genes Y and Z are on different chromosomes.
d.
both A and C.
e.
both B and C
 106.
Which of the following is true regarding linkage maps? They
a.
always have a total of 100 map units.
b.
can be used to pinpoint the precise physical position of a gene on a chromosome.
c.
are a genetic map based on recombination frequencies.
d.
require preparation of karyotypes.
e.
reflect the frequency of crossing over between X and Y chromosomes.
 107.
The frequency of crossing over between any two linked genes is
a.
higher if they are recessive.
b.
different between males and females.
c.
determined by their relative dominance.
d.
the same as if they were not linked.
e.
proportional to the distance between them.
 108.
Sturtevant provided genetic evidence for the existence of four pairs of chromosomes in Drosophila by showing that
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.
the entire Drosophila genome has approximately 400 map units.
e.
Drosophila genes have, on average, four different alleles.
 109.
Map units on a linkage map cannot be relied upon to calculate physical distances on a chromosome because
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.
e.
all of the above
 110.
A map of a chromosome that includes the positions of genes relative to visible chromosomal features, such as stained bands, is called a
a.
linkage map.
b.
physical map.
c.
recombination map.
d.
cytogenetic map.
e.
banded map.
 111.
Males are more often affected by sex-linked traits than females because
a.
males are hemizygous for the X chromosome.
b.
male hormones such as testosterone often exacerbate the effects of mutations on the X chromosome.
c.
female hormones such as estrogen often compensate for the effects of mutations on the X.
d.
X chromosomes in males generally have more mutations than X chromosomes in females.
e.
mutations on the Y chromosome often exacerbate the effects of X-linked mutations.
 112.
SRY is
a.
a gene present on the Y chromosome that triggers male development.
b.
a gene present on the X chromosome that triggers female development.
c.
an autosomal gene that is required for the expression of genes on the Y chromosome.
d.
an autosomal gene that is required for the expression of genes on the X chromosome.
e.
required for development, and males or females lacking the gene do not survive past early childhood.
 113.
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 female; tortoiseshell male
b.
black female; orange male
c.
orange female; orange male
d.
tortoiseshell female; black male
e.
orange female; black male
 114.
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.
XcXc and XcY
b.
XcXc and XCY
c.
XCXC and XcY
d.
XCXC and XCY
e.
XCXc and XCY
 115.
In the following list, which term is least related to the others?
a.
Duchenne muscular dystrophy
b.
autosome
c.
sex-linked genes
d.
color blindness
e.
hemophilia
 116.
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.
75%
e.
100%
 117.
Most calico cats are female because
a.
a male inherits only one of the two X-linked genes controlling hair color.
b.
the males die during embryonic development.
c.
the Y chromosome has a gene blocking orange coloration.
d.
only females can have Barr bodies.
e.
multiple crossovers on the Y chromosome prevent orange pigment production.
 118.
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 a son of this couple will be color-blind?
a.
0
b.
1/4
c.
1/2
d.
3/4
e.
1
 119.
In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A lethal recessive 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.
4:3 male to female
e.
3:1 male to female
 120.
A man who carries an X-linked allele will pass it on to
a.
all of his daughters.
b.
half of his daughters.
c.
all of his sons.
d.
half of his sons.
e.
all of his children.

Refer to the information below to answer the following questions.

An achondroplastic male 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.

 121.
How many of their daughters might be expected to be color-blind dwarfs?
a.
all
b.
none
c.
half
d.
one out of four
e.
three out of four
 122.
How many of their sons would be color-blind and of normal height?
a.
all
b.
none
c.
half
d.
one out of four
e.
three out of four
 123.
They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?
a.
0
b.
0.25
c.
0.50
d.
0.75
e.
1.00
 124.
Male calico cats could be the result of
a.
sex-linked inheritance.
b.
nondisjunction, leading to the male calico having two X chromosomes.
c.
incomplete dominance of multiple alleles.
d.
recessive alleles retaining their fundamental natures even when expressed.
e.
a reciprocal translocation.
 125.
A Barr body is normally found in the nucleus of which kind of human cell?
a.
unfertilized egg cells only
b.
sperm cells only
c.
somatic cells of a female only
d.
somatic cells of a male only
e.
both male and female somatic cells
 126.
Which of these syndromes afflicts mostly males?
a.
Turner syndrome
b.
Down syndrome
c.
Duchenne muscular dystrophy
d.
cri du chat syndrome
e.
chronic myelogenous leukemia
 127.
If a human interphase nucleus of a person contains three Barr bodies, it can be assumed that the person
a.
has hemophilia.
b.
is a male.
c.
has four X chromosomes.
d.
has Turner syndrome.
e.
has Down syndrome.
 128.
If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis?
a.
All the gametes will be diploid.
b.
Two gametes will be n + 1, and two will be n – 1.
c.
One gamete will be n + 1, one will be n – 1, and two will be n.
d.
There will be three extra gametes.
e.
Two of the four gametes will be haploid, and two will be diploid.
 129.

The figure below represents the stained nucleus from a cheek epithelial cell of an individual whose genotype would probably be

mc129-1.jpg

a.
XX.
b.
XY.
c.
XYY.
d.
XXX.
e.
XXY.
 130.
If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be 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
e.
n – 1; n – 1; n; n
 131.
A cell that has 2n + 1 chromosomes is
a.
trisomic.
b.
monosomic.
c.
aneuploid.
d.
polyploid.
e.
both A and C
 132.
If a chromosome lacks certain genes, what has most likely occurred?
a.
disjunction
b.
an inversion
c.
a deletion
d.
a translocation
e.
a nonduplication
 133.
One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. This is called a (an)
a.
deletion.
b.
disjunction.
c.
inversion.
d.
translocation.
e.
duplication.
 134.
In the following list, which term is least related to the others?
a.
trisomic
b.
monosomic
c.
aneuploid
d.
triploid
e.
nondisjunction
 135.
A nonreciprocal crossover causes which of the following products?
a.
deletion
b.
duplication
c.
nondisjunction
d.
A and B
e.
B and C
 136.
One possible result of chromosomal breakage can be that a fragment reattaches to the original chromosome in a reverse orientation. This is called
a.
disjunction.
b.
translocation.
c.
deletion.
d.
inversion.
e.
aneuploidy.
 137.
A human individual is phenotypically female, but her interphase somatic nuclei do not show the presence of Barr bodies. Which of the following statements concerning her is probably true?
a.
She has Klinefelter syndrome.
b.
She has an extra X chromosome.
c.
She has Turner syndrome.
d.
She has the normal number of sex chromosomes.
e.
She has two Y chromosomes.
 138.

The karyotype shown below is associated with which of the following genetic disorders?

mc138-1.jpg

a.
Turner syndrome
b.
Down syndrome
c.
Klinefelter syndrome
d.
hemophilia
e.
male-pattern baldness
 139.
In humans, male-pattern baldness is controlled by a gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald?
a.
0%
b.
25%
c.
33%
d.
50%
e.
75%
 140.
Of the following human trisomies, the one that generally has the most severe impact on the health of the individual is
a.
trisomy 21.
b.
Klinefelter syndrome (XXY).
c.
trisomy X.
d.
XYY.
e.
All of the above have equal impact.
 141.
What do all human males inherit from their mother?
a.
mitochondrial DNA
b.
an X chromosome
c.
the SRY gene
d.
A and B only
e.
A, B, and C
 142.
Which of the following statements is true regarding genomic imprinting?
a.
It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele.
b.
It is greatest in females because of the larger maternal contribution of cytoplasm.
c.
It may explain the transmission of Duchenne muscular dystrophy.
d.
It involves an irreversible alteration in the DNA sequence of imprinted genes.
e.
All of the above are correct.
 143.

The pedigree in the figure below shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely

mc143-1.jpg

a.
mitochondrial.
b.
autosomal recessive.
c.
sex-linked dominant.
d.
sex-linked recessive.
e.
autosomal dominant.
 144.
Which of the following statements about mitochondria is false?
a.
Because of the role of the mitochondria in producing cellular energy, mitochondrial diseases often affect the muscles and nervous system.
b.
Because mitochondria are present in the cytoplasm, mitochondrial diseases are transmitted maternally.
c.
Like nuclear genes, mitochondrial genes usually follow Mendelian patterns of inheritance.
d.
Mitochondria contain circular DNA molecules that code for proteins and RNAs.
e.
Many mitochondrial genes encode proteins that play roles in the electron transport chain and ATP synthesis.
 

Short Answer
Self-Quiz Questions
 145.
A man with hemophilia (a recessive, sex-linked condition. has a daughter of normal phenotype) She marries a man who is normal for the trait. What is the probability that a daughter of this mating will be a hemophiliac? That a son will be a hemophiliac? If the couple has four sons, what is the probability that all four will be born with hemophilia?

 146.
Pseudohypertrophic muscular dystrophy is an inherited disorder that causes gradual deterioration of the muscles. It is seen almost exclusively in boys born to apparently normal parents and usually results in death in the early teens. Is this disorder caused by a dominant or a recessive allele? Is its inheritance sex-linked or autosomal? How do you know? Explain why this disorder is almost never seen in girls.

 147.
Red-green color blindness is caused by a sex-linked recessive allele. A color-blind man marries a woman with normal vision whose father was color-blind. What is the probability that they will have a color-blind daughter? What is the probability that their first son will be color-blind? (Note: The two questions are worded a bit differently).

 148.
A wild-type fruit fly (heterozygous for gray body color and normal wings) is mated with a black fly with vestigial wings. The offspring have the following phenotypic distribution: wild type, 778; black-vestigial, 785; black-normal, 158; gray-vestigial, 162. What is the recombination frequency between these genes for body color and wing size?

 149.
In another cross, a wild-type fruit fly (heterozygous for gray body color and red eyes) is mated with a black fruit fly with purple eyes. The offspring are as follows: wild type, 721; black-purple, 751; gray-purple, 49; black-red, 45. What is the recombination frequency between these genes for body color and eye color? Using information from problem 4, what fruit flies (genotypes and phenotypes) would you mate to determine the sequence of the body-color, wing-size, and eye-color genes on the chromosome?

 150.
What pattern of inheritance would lead a geneticist to suspect that an inherited disorder of cell metabolism is due to a defective mitochondrial gene?

 151.
Women born with an extra X chromosome (XXX) are healthy and phenotypically indistinguishable from normal XX women. What is a likely explanation for this finding? How could you test this explanation?

 152.
Determine the sequence of genes along a chromosome based on the following recombination frequencies: A-B, 8 map units; A-C, 28 map units; A-D, 25 map units; B-C, 20 map units; B-D, 33 map units.

 153.
Assume that genes A and B are linked and are 50 map units apart. An animal heterozygous at both loci is crossed with one that is homozygous recessive at both loci. What percentage of the offspring will show phenotypes resulting from crossovers? If you did not know that genes A and B were linked, how would you interpret the results of this cross?

 154.
A space probe discovers a planet inhabited by creatures who reproduce with the same hereditary patterns seen in humans. Three phenotypic characters are height (T = tall, t = dwarf), head appendages (A = antennae, a = no antennae), and nose morphology (S = upturned snout, s = downturned snout). Since the creatures are not “intelligent,” Earth scientists are able to do some controlled breeding experiments, using various heterozygotes in testcrosses. For tall heterozygotes with antennae, the offspring are: tall-antennae, 46; dwarf-antennae, 7; dwarf-no antennae, 42; tall-no antennae, 5. For heterozygotes with antennae and an upturned snout, the offspring are: antennae-upturned snout, 47; antennae-downturned snout, 2; no antennae-downturned snout, 48; no antennae-upturned snout, 3. Calculate the recombination frequencies for both experiments.

 

Introduction to Biology Quiz 2

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Name: 

Introduction to Biology

 

 

True/False
Indicate whether the sentence or statement is true or false.
1.
Only multicellular organisms use energy for growth and maintenance.
2.
Scientific investigations always follow a series of rigidly defined steps.
3.
Communicating scientific information may result in the development of new hypotheses.
4.
All living things are composed of cells.
5.
In a carefully planned experiment, the variable being studied is omitted from the experimental group.
6.
Scientific understanding is based on observations.
7.
Reproduction is essential for the survival of individual organisms.
8.
The processes of observing, measuring, and organizing data generally lead to the formulation of questions.
9.
Observing is the use of one or more of the senses to perceive objects or events.
10.
The study of biology can help you better understand human reproduction.
11.
Almost all organisms ultimately get their energy for survival from the sun.
12.
A scientist who performs an experiment has no idea what the outcome of the experiment is going to be.
13.
Units of time are not measured in metric units, so time measurements are not accepted for use with SI units.
 

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
14.
The step in a scientific method that is most likely to take the form of an IF_THEN statement is called:
a.
prediciton
c.
experimenting
b.
inference
d.
modeling
15.
The number of frogs in a pond increases each year due to:
a.
homeostasis
c.
organization
b.
reproduction
d.
the food chain
16.
When an experiment gives an important result, these results should not be
a.
published.
c.
replicated.
b.
withheld.
d.
confirmed.
17.
When a hypothesis is tested and confirmed often enough that it is unlikely to be disproved the hypothesis may become a
a.
theory.
c.
replication.
b.
prediction.
d.
scientific method.
18.
Generally, the order in which a scientist uses the scientific method is
a.
observations, predictions, hypothesis, verifying prediction,theory, verification.
b.
observations, hypothesis, making predictions, verifying predictions, performing control
experiments,theory.
c.
predictions, observations, hypothesis, theory, controlled testing,verification.
d.
observations, hypothesis, predictions, verification, theory.
19.
Generally the first process a scientist uses to obtain knowledge about nature is:
a.
collecting
c.
predicting
b.
observing
d.
measuring
20.
Which of the following steps in scientific method is most likely to directly follow
hypothesizing?
a.
communicating
c.
experimenting
b.
inferring
d.
predicting
21.
The part of the scientific method in which journal articles are prepared is called:
a.
communicating
c.
organizing
b.
observing
d.
classifying
22.
A control
a.
is when a lead scientist controls a group of scientists conducting an experiment.
b.
is always registered with the Food and Drug Administration (FDA).
c.
is the part of an experiment in which a key factor is not allowed to change.
d.
provides the answer to a problem posed by a theory.
23.
Biology is the study of
a.
minerals.
c.
the weather
b.
life.
d.
energy.
24.
Which of the following shows the most complex level of organization?
a.
red blood cells
c.
nerve
b.
stomach
d.
muscle
25.
In the scientific method, the step that follows observing and stating a  problem is
a.
recording data.
c.
forming a hypothesis.
b.
analyzing data.
d.
testing a hypothesis.
26.
The splitting in two of a bacterium is called:
a.
inheritance
c.
development
b.
sexual reproduction
d.
asexual reproduction
27.
Plants and algae use energy that comes from
a.
the sun.
b.
the movement of the Earth.
c.
the moon.
d.
heat created deep within the interior of the Earth.
28.
The first living organism on earth was probably a:
a.
single cell
c.
dinosaur
b.
fish
d.
plant
29.
In the scientific method, a possible explanation is called:
a.
hypothesis
c.
an observation
b.
an inference
d.
an analysis
30.
Cell membranes
a.
are only found on a small number of cells.
c.
are made of DNA
b.
contain genes.
d.
are thin coverings that surround cells.
31.
The combining of genetic information from two individuals to produce offspring is called:
a.
inheritance
c.
sexual reproduction
b.
development
d.
asexual reproduction
32.
All organisms possess DNA. DNA
a.
creates energy for the cells.
b.
allows sensitivity to environmental stimuli.
c.
contains information for growth and development.
d.
captures energy from the sun.
33.
Instructions for development that are passed from parents to offspring are known as
a.
a species plan.
c.
genes.
b.
organ codes.
d.
natural selections.
34.
Which of the following is not necessarily a distinct property of living things?
a.
homeostasis
c.
complexity
b.
metabolism
d.
reproduction
35.
Living things
a.
need energy for life processes.
c.
are composed of cells.
b.
have the ability to reproduce.
d.
All of the above
36.
All living things maintain a balance within their cells and the environment through the process of
a.
growth.
c.
homeostasis.
b.
development.
d.
evolution.
37.
Which of the following is not a partial explanation for our lack of understanding of many of the living things on Earth?
a.
Many organisms are microscopic in size and therefore difficult to observe.
b.
Many organisms are so different from other organisms that it is difficult to understand them.
c.
Many organisms live in areas of the world that are difficult to explore.
d.
Tropical rain forests contain many species, and it is difficult to find all of them in these dense forests.
38.
Which example of scientific methodology is incorrect?
a.
Observation—A number of people in Zaire dying of a disease outbreak
b.
Measurement—A record of the number of people with symptoms of the disease and the number of people who had died from the disease
c.
Analysis of data—Comparison of the effects of mixing monkey cells with virus-containing blood in test tubes and the effects of mixing of liquid from these test tubes with fresh monkey cells
d.
Inference making—Identification of the Ebola virus as the cause of the disease by taking electron micrographs of substances found in the blood of persons affected with the disease
39.
The word theory used in a scientific sense means
a.
that of which the scientist is most certain.
b.
a guess made with very little knowledge to support it.
c.
an absolute scientific certainty.
d.
None of the above
40.
A light microscope that has an objective lens of 10´ and an ocular lens of 20´ has a magnification of
a.
30´.
c.
300´.
b.
200´.
d.
2000´.

 

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Chapter 5 – Cell Transport Study Guide

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Chapter 5 Cell Transport studyguide

 

 

Modified True/False
Indicate whether the statement is true or false.  If false, change the identified word or phrase to make the statement true.
 1.
One way that cells maintain homeostasis is by controlling the movement of substances across the cell membrane. _________________________


 2.
The cell membrane is made up of a double layer called the DNA bilayer. _________________________


 3.
A phospholipid is made up of a lipid “head” and two fatty acid “tails.” _________________________


 4.
The nonpolar tails of a phospholipid are attracted to water. _________________________


 5.
Cell-surface markers face the inside of the cell. _________________________


 6.
A concentration gradient exists when one area has a higher concentration of a substance than another area does. _________________________


 7.
The movement down a concentration gradient is called diffusion. _________________________


 8.
When the solute concentration outside a cell is equal to the solute concentration inside the cell, the cell’s environment is hypotonic. _________________________


 9.
A cell placed in a high salt solution would swell because of osmosis. _________________________


 10.
Osmosis is the diffusion of starch molecules through a selectively permeable membrane. _________________________


 11.
To pass through a cell membrane, water requires carrier proteins. _________________________


 12.
Facilitated diffusion is an active process that requires a cell to expend a great deal of energy. _________________________


 13.
Passive transport uses ATP to move molecules against their concentration gradient. _________________________


 14.
Exocytosis is a process that uses vesicles to capture substances and bring them into a cell. _________________________


 15.
Cells use exocytosis to export proteins modified by the Golgi apparatus. _________________________


 16.
Cells communicate by sending chemical signals that carry information to other cells. _________________________


 17.
Receptor proteins bind only to signals that match the specific color of the binding site. _________________________


 18.
Receptor proteins may cause the formation of a second messenger molecule inside the cell. _________________________


 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 19.
cell membrane : cell ::
a.
window : house
c.
door : house
b.
roof : house
d.
wall : house
 20.
Which type of molecule forms the cell membrane?
a.
protein
c.
nucleic acid
b.
phospholipid
d.
carbohydrate
 21.
Phospholipids are molecules that have
a.
one polar phosphate head and two polar fatty acid tails.
b.
one polar phosphate head and two nonpolar fatty acid tails.
c.
one polar phosphate head and one polar fatty acid tail.
d.
one nonpolar phosphate head and two polar fatty acid tails.
 22.
The interior of the lipid bilayer of a cell membrane forms a nonpolar zone that
a.
allows most polar molecules to pass through the membrane.
b.
allows food to pass through the membrane.
c.
repels ions and most polar molecules.
d.
makes the membrane permeable to most molecules.
nar001-1.jpg
 23.
Refer to the illustration above. The structure labeled A is composed of
a.
lipids.
c.
proteins.
b.
carbohydrates.
d.
DNA.
 24.
Refer to the illustration above. The structure labeled D is a(n)
a.
cell-surface marker.
c.
enzyme.
b.
receptor protein.
d.
transport protein.
 25.
Refer to the illustration above. The structure labeled C is a(n)
a.
cell-surface marker.
c.
enzyme.
b.
receptor protein.
d.
transport protein.
 26.
Proteins in the cell membrane that identify the cell are called
a.
cell-surface markers.
c.
enzymes.
b.
receptor proteins.
d.
transport proteins.
 27.
As a result of diffusion, the concentration of many types of substances
a.
always remains greater inside a membrane.
b.
eventually becomes balanced on both sides of a membrane.
c.
always remains greater outside of a membrane.
d.
becomes imbalanced on both sides of a membrane.
nar002-1.jpg
 28.
Refer to the illustration above. The process shown is called
a.
osmosis.
c.
active transport.
b.
facilitated diffusion.
d.
diffusion.
 29.
Diffusion is the movement of a substance
a.
only through a lipid bilayer membrane.
b.
from an area of low concentration to an area of higher concentration.
c.
only in liquids.
d.
from an area of high concentration to an area of lower concentration.
 30.
The dispersal of ink in a beaker of water is an example of
a.
diffusion.
c.
active transport.
b.
osmosis.
d.
endocytosis.
 31.
Proteins that serve as tunnels for specific substances through the lipid bilayer are
a.
cell-surface markers.
c.
receptor proteins.
b.
channel proteins.
d.
enzymes.
 32.
Sugar molecules cross the cell membrane by
a.
active transport.
c.
osmosis.
b.
facilitated diffusion.
d.
simple diffusion.
 33.
Which of the following does not require energy?
a.
diffusion
c.
active transport
b.
endocytosis
d.
sodium-potassium pump
 34.
Ions move through ion channels by
a.
endocytosis.
c.
passive transport.
b.
simple diffusion.
d.
active transport.
 35.
The diffusion of water into or out of a cell is called
a.
solubility.
c.
selective transport.
b.
osmosis.
d.
endocytosis.
 36.
Osmosis is a type of
a.
active transport.
c.
simple diffusion.
b.
passive transport.
d.
endocytosis.
 37.
How does water pass through the cell membrane?
a.
directly through the lipid bilayer
b.
through a water ion pump
c.
through water carrier proteins
d.
through channel proteins just for water
 38.
Which of the following statements about an isotonic solution and a cell is correct?
a.
The solution has the same solute concentration that the cytoplasm does.
b.
The solution has a higher solute concentration than the cytoplasm does.
c.
A cell in the solution will lose water.
d.
A cell in the solution will gain water.
 39.
Unlike passive transport, active transport
a.
requires energy.
b.
moves substances down their concentration gradient.
c.
does not involve carrier proteins.
d.
moves water across the cell membrane.
 40.
Both active transport and facilitated diffusion involve
a.
ATP.
b.
movement against a concentration gradient.
c.
carrier proteins.
d.
channel proteins.
 41.
Which of the following is a form of active transport?
a.
osmosis
c.
facilitated diffusion
b.
simple diffusion
d.
sodium-potassium pump
 42.
The sodium-potassium pump
a.
is a carrier protein.
c.
is located in the cytoplasm of a cell.
b.
uses passive transport.
d.
transports sugar molecules.
 43.
The sodium-potassium pump usually pumps
a.
potassium ions out of the cell.
b.
sodium ions into the cell.
c.
potassium ions into the cell.
d.
only potassium ions and sugar molecules.
 44.
How many potassium ions does the sodium-potassium pump move into a cell if it moves six sodium ions out of the cell?
a.
two
c.
six
b.
four
d.
eight
 45.
Proteins and polysaccharides that are too large to move into a cell through diffusion or active transport move in by
a.
exocytosis.
c.
the sodium-potassium pump.
b.
endocytosis.
d.
channel proteins.
 46.
Molecules that are too large to be moved across a cell membrane can be removed from the cell by
a.
diffusion.
c.
endocytosis.
b.
exocytosis.
d.
osmosis.
 47.
Removing materials from a cell in vesicles is called
a.
osmosis.
c.
exocytosis.
b.
diffusion.
d.
endocytosis.
 48.
Which of the following descriptions of hormones is correct?
a.
signal molecules distributed throughout the body
b.
signal molecules that affect all cells in the body
c.
target molecules that communicate through direct contact
d.
target molecules that originate outside the body
nar003-1.jpg
 49.
Refer to the illustration above. What happens when the structure labeled A binds to the structure labeled B?
a.
Information is sent into the cell.
c.
The cell begins to swell.
b.
Proteins enter the cell.
d.
Ions enter the cell.
 50.
Refer to the illustration above. The structure labeled B in the diagram is an example of a(n)
a.
channel protein.
c.
receptor protein.
b.
signal molecule.
d.
ion pump.
 51.
Signal molecules bind to
a.
carbohydrates.
c.
receptor proteins.
b.
marker proteins.
d.
transport proteins.
 52.
Which of the following transmit information into a cell by binding to signal molecules?
a.
channel proteins
c.
marker proteins
b.
receptor proteins
d.
signal proteins
 53.
What change takes place in the cell membrane if a signal molecule causes a transport protein to open?
a.
permeability change
c.
formation of a second messenger
b.
activation of an enzyme
d.
change in chemical reactions
 

Completion
Complete each statement.
 54.
One way cells maintain homeostasis is by controlling the movement of substances across the cell ____________________.

 55.
A(n) ____________________ is a specialized lipid made of a phosphate head and two fatty acid tails.

 56.
The phosphate head of a phospholipid is attracted to water because it is ____________________.

 57.
The fatty acid tails of a phospholipid are repelled by water because they are ____________________.

 58.
The phospholipids form a barrier through which only small, ____________________ substances can pass.

 59.
Ions and most polar molecules are repelled by the ____________________ interior of the lipid bilayer.

 60.
____________________ – ____________________ markers are attached to the cell surface and have sugars attached to their protein.

 61.
Proteins that aid in moving substances into and out of cells are called ____________________ proteins.

 62.
____________________ are proteins in the cell membrane that help with important biochemical reactions inside the cell.

 63.
____________________ proteins enable a cell to sense its surroundings by binding to certain substances outside the cell.

 64.
To reach equilibrium, substances always flow from an area of high concentration to an area of ____________________ concentration.

 65.
When one area has a higher concentration than another area does, a concentration ____________________ exists.

 66.
Substances diffuse through a cell membrane either through the lipid bilayer or through ____________________ proteins.

 67.
Oxygen and carbon dioxide pass through the lipid bilayer by ____________________ diffusion.

 68.
Diffusion of ions through ion channels is a form of ____________________ transport.

 69.
Carrier proteins change ____________________ to transport substances to the interior of cells.

 70.
A cell does not expend ____________________ when diffusion takes place.

 71.
The diffusion of ____________________ through cell membranes is called osmosis.

 72.
When the concentration of free water molecules is higher outside a cell than inside the cell, water will diffuse ____________________ the cell.

 73.
If a cell is placed in a(n) ____________________ solution, water will flow out of the cell.

 74.
If a cell is placed in a(n) ____________________ solution, water will flow into the cell.

 75.
If a cell is placed in a(n) ____________________ solution, water flows into the cell at a rate that is equal to the rate at which water flows out of the cell.

 76.
Active transport requires the use of ____________________ by a cell.

 77.
The ____________________ – ____________________ pump transports ions against their concentration gradients.

 78.
The sodium-potassium pump uses energy supplied by ____________________.

 79.
The sodium-potassium pump prevents the accumulation of ____________________ ions inside the cell.

 80.
The movement of a substance into a cell by a vesicle is called ____________________.

nar004-1.jpg
A
B
 81.
Refer to the illustration above. The process shown in figure B is called ____________________.

 82.
Refer to the illustration above. The process shown in figure A is called ____________________.

 83.
A signaling cell produces a signal that is detected by a ____________________ cell.

 84.
Light is an environmental ____________________ for the flowering of some plants.

 85.
In the cell membrane, proteins that bind to specific signal molecules and respond are called ____________________ proteins.

 86.
Receptor proteins can change the ____________________ of the cell membrane.

 87.
Receptor proteins may act as ____________________, triggering certain chemical reactions inside the cell.

 

Short Answer
 88.
In addition to its function as a gatekeeper, what are three other functions of the cell membrane?

 89.
What makes up the lipid bilayer?

 90.
In the lipid bilayer, what causes one layer of polar heads to face the cell’s cytoplasm and the other layer of heads to face the cell’s surroundings?

 91.
What characteristic of membrane proteins causes them to be held in the cell membrane?

 92.
What are four types of proteins in cell membranes?

 93.
What exists across a cell membrane if equilibrium is not reached?

 94.
What is the difference between how a molecule crosses the cell membrane in simple diffusion and in facilitated diffusion?

 95.
What are two types of transport proteins?

 96.
Why are some water molecules not free to move across the cell membrane?

 97.
Explain why osmosis is a form of facilitated diffusion.

 98.
What specific carrier protein moves sodium ions out of a cell and potassium ions into a cell?

 99.
What is the function of the cell membrane during endocytosis?

 100.
What are hormones, how are they distributed, and what cells do they affect?

 101.
What happens to a receptor protein once it binds to a signal molecule?

 102.
How can the cell’s response to a signal cause a permeability change?

 

Problem
 103.

A biologist conducts an experiment designed to determine whether a particular type of molecule is transported into cells by simple diffusion, facilitated diffusion, or active transport. He collects the following information:

1. The molecule is very small.
2. The molecule is polar.
3. The molecule can accumulate inside a cell, even when its concentration inside the cell initially is higher than it is outside the cell.
4. Cells use up more energy when the molecule is present in the environment around the cells than when it is not present.

The biologist concludes that the molecule moves across cell membranes by facilitated diffusion. Do you agree with his conclusion? Why or why not?

Paramecia are unicellular protists. They have a number of characteristics also found in animals, such needing to ingest food in order to obtain energy and being surrounded by a cell membrane but not by a rigid cell wall. Paramecia have organelles found in animal cells, including a nucleus, mitochondria, ribosomes, and cilia. In addition, they have star-shaped organelles, called contractile vacuoles, that expel excess water. The illustration below depicts a paramecium.

nar005-1.jpg

 104.

Refer to the illustration above. The data presented in the table below were obtained in an experiment in which paramecia were placed in salt water with different concentrations of salt and the rate at which their contractile vacuoles contracted to pump out excess water was recorded.

Salt Concentration
Number of contractile vacuole contractions/minute
Very high
2
High
8
Medium
15
Low
22
Very low
30

 

a. How can you explain the observed relationship between salt concentration and rate of contractile vacuole contraction?
b. If something happened to a paramecium that caused its contractile vacuoles to stop contracting, what would you expect to happen? Would this result occur more quickly if the paramecium was in water with a high salt concentration or in water with a low salt concentration? Why?

 

Essay
 105.
Distinguish between facilitated diffusion and active transport.

 106.
Compare the processes of sodium ions moving through the cell membrane by an ion channel and by an ion pump.

 107.
Why do dissolved particles on one side of a membrane result in the diffusion of water across the membrane?

 108.
Why is it dangerous for humans to drink seawater?

nar004-1.jpg
A
B
 109.
Refer to the illustration above. Identify and explain the processes taking place in figure A and figure B.

 110.
Describe three ways in which the binding of a signal molecule to a receptor protein can change the functioning of a cell.

 

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Dihybrid Crosses Quiz

%CODE1% Dihybrid Crosses Quiz

 

 

 

1. An organism of genotype AaBb can make gametes of all the following kinds except:

a. AB
b. Bb
c. aB
d. ab

 

2. If AaBb is crossed with aabb, what proportion of the offspring would be expected to be aabb?

a. 9/16
b. 1/8
c. 1/4
d. 1/16

 

3. If the offspring of a cross show a 9/16 to 3/16 to 3/16 to 1/16 ratio (9:3:3:1), the parents of the cross have the genotypes

a. AaBb x AaBb
b. AaBb x aaBB
c. aaBb x aabb
d. aaBb x Aabb

 

4. Whenever a capital letter is present, a red color is produced. In a cross of AaBb x AaBb, how many red offspring would you expect out of 16?

a. 1
b. 3
c. 9
d. 15

 

5. Assume that you mated two individuals heterozygous for each of two traits and obtained 80 offspring. How many of them would be expected to look like their parents?

a. 25
b. 45
c. 60
d. 80

 

6. Genes that assort independently are

a. located on different chromosomes
b. located on the same chromosome
c. alleles of each other
d. dominant

 

7. If W = purple flower and w = white, and D = tall plants and d = short plants, a wwDd plant would be

a. purple and tall
b. purple and short
c. white and tall
d. white and short

 

8. If two true-breeding parents are crossed with each other and all the offspring have their mother’s ears and their father’s tail, the parents in the cross would be

a. EETT x eett
b. eeTT x EEtt
c. EeTt x EeTt
d. eeTt x Eett

 

9. If aaBb is crossed with AAbb, what proportion of the offspring will be AAbb?

a. 0
b. 3/16
c. 9/16
d. 1/4

 

10. If AaBb is crossed with AaBb, what proportion of the offspring will be dominant for the ‘A/a’ trait and recessive for the ‘B/b’ trait (i.e. A-bb)?

a. 9/16
b. 3/16
c. 1/16
d. 0