BSC 2010 exam 2 (genetics) Questions
with 100% Correct Answers
Gregor Mendel first presented his theories to the public in - ANSWERS1865
Which of the following is not a characteristic that makes an organism suitable for
genetic studies? - ANSWERSA small number of chromosomes
If Mendel had performed experiments on cattle rather than on peas, the patterns of
inheritance would not have been easily detectable because cattle - ANSWERShave
small numbers of offspring
Which of the following is a characteristic of the common garden pea that made it
suitable for Mendel's breeding experiments? - ANSWERSThey are "true-breeding."
Their pollination can be controlled.
If two strains of true-breeding plants that have different alleles for a certain character
are crossed, their progeny are called - ANSWERSthe F1 generation.
Which of the following methods was not used by Mendel in his study of the genetics of
the garden pea? - ANSWERSMicroscopy
Mendel's crossing of spherical-seeded pea plants with wrinkled-seeded pea plants
resulted in progeny that all had spherical seeds. This indicates that the wrinkled-seed
traits is - ANSWERSrecessive
If a trait that is not expressed in the F1 generation reappears in the F2 generation, the
inheritance of the trait in question is an example of - ANSWERSdominance and
recessiveness
Mendel concluded that each pea has two units for each character, and each gamete
contains one unit. Mendel's "unit" is now referred to as a - ANSWERSgene
Different forms of a gene are called - ANSWERSalleles
At a certain locus of the human genome, 200 different alleles exist in the population.
Each person has at most ___ alleles - ANSWERS2
Which statement about an individual that is homozygous for an allele is false? -
ANSWERSIts parents were necessarily homozygous for that allele
,In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short
plants and the F1 plants, which are all tall, are allowed to self-pollinate. What fraction of
the F2 generation are both tall and heterozygous? - ANSWERS1/2
Which statement about the inheritance of shell shape in tortoises is most likely to be
correct, given your genetic analysis of the tortoise family? - ANSWERSRound is
dominant to lumpy
Which statement about the inheritance of footedness in tortoises is most likely to be
correct, given your genetic analysis of the tortoise family? - ANSWERSBig and small
are codominat
If big feet (B) in tortoises is dominant to small feet (b), which of the following is the
genotype of the big-footed parent with respect to the foot gene? - ANSWERSBb
The physical appearance of a character is called - ANSWERSthe phenotype
A pea plant with red flowers is test crossed, and one-half of the resulting progeny have
red flowers, while the other half has white flowers. Therefore, the genotype of the test-
crossed parent was - ANSWERSRr
A particular genetic cross in which the individual in question is crossed with an
individual known to be homozygous for a recessive trait is referred to as a -
ANSWERStest cross
Which statement about a test cross is false? - ANSWERSIf the test individual is
homozygous, the progeny will have a 3:1 ratio
In a __ cross, genes for two different characters separate. - ANSWERSdihybrid
In garden peas, the alleles for tall plants is dominant over the allele for short plants. A
true-breeding tall plant is crossed with a short plant, and one the their offspring is test
crossed. Out of 20 offspring resulting resulting from the test cross, about __ should be
tall. - ANSWERS10
The genotype of an organism that expresses a dominant trait can be determined by -
ANSWERScrossing the organism with a homozygous recessive organism
In mice, short hair is dominant to long hair. If a short-haired individual is crossed with a
long-haired individual and both long- and short-haired offspring result, one can conclude
that - ANSWERSthe short-haired parent is heterozygous
Classical albinism results from a recessive allele. Which of the following is the expected
ratio for the progeny when a normally pigmented male with a albino father has children
with an albino woman? - ANSWERS1/2 normal, 1/2 albino
, Which of the following statements about a dihybrid cross is true? - ANSWERSIt is a
cross between identical double heterozygotes
Mendel's dihybrid crosses - ANSWERSAll of the above
In cocker spaniels, black color (B) is dominant over red (b), and solid color (S) is
dominant over spotted (s). If the genes are unlinked, and the offspring of BBss and bbss
individuals are mated with each other, what fraction of the next generation will be black
and spotted? - ANSWERS3/4
In humans, a widow's peak is caused by a dominant allele (W), and a continuous
hairline is caused by a recessive allele (w). Short fingers are caused by a dominant
allele (S), and long fingers are caused by a recessive allele (s). Suppose a woman with
a continuous hairline and short fingers and a man with a widow;s peach and long
fingers have three children. One child has short fingers and a widow's peak, one has
long fingers and a widow's peak, and one has long fingers and a continuous hairline.
What are the genotypes of the parents? - ANSWERSFemale wwSs, male Wwss
In dogs, phenotype A is caused by dominant alleles; phenotype B is caused by
recessive alleles. A dog that is homozygous for both traits of phenotype A is mated to a
dog with phenotype B. If the genes for the two traits are unlinked, which of the following
is the expected F1 phenotypic ratio? - ANSWERS1:0
Segregation of alleles occurs - ANSWERSduring gamete formation
Separation of the alleles of a single gene into different gametes is called -
ANSWERSsegregation
One of the major contributions of Mendel to the study of genetics was - ANSWERSthe
use of a quantitative approach to analyze data
Mendel performed a cross between individuals heterozygous for three different traits:
green versus yellow seeds, red versus white flowers, and green versus yellow pods.
What fraction of the offspring would have been expected to have green seeds, red
flowers and green pods? - ANSWERS27/64
Genetic mutations are - ANSWERSAll of the above
The particular allele of a gene that is present in most individuals in nature is referred to
as - ANSWERSwild type
Which of the following statements about Mendelian genetics is false? - ANSWERSIn
any population, only two alleles can exist for a given gene.
What percent of the progeny are likely to be albino? - ANSWERS50 percent
with 100% Correct Answers
Gregor Mendel first presented his theories to the public in - ANSWERS1865
Which of the following is not a characteristic that makes an organism suitable for
genetic studies? - ANSWERSA small number of chromosomes
If Mendel had performed experiments on cattle rather than on peas, the patterns of
inheritance would not have been easily detectable because cattle - ANSWERShave
small numbers of offspring
Which of the following is a characteristic of the common garden pea that made it
suitable for Mendel's breeding experiments? - ANSWERSThey are "true-breeding."
Their pollination can be controlled.
If two strains of true-breeding plants that have different alleles for a certain character
are crossed, their progeny are called - ANSWERSthe F1 generation.
Which of the following methods was not used by Mendel in his study of the genetics of
the garden pea? - ANSWERSMicroscopy
Mendel's crossing of spherical-seeded pea plants with wrinkled-seeded pea plants
resulted in progeny that all had spherical seeds. This indicates that the wrinkled-seed
traits is - ANSWERSrecessive
If a trait that is not expressed in the F1 generation reappears in the F2 generation, the
inheritance of the trait in question is an example of - ANSWERSdominance and
recessiveness
Mendel concluded that each pea has two units for each character, and each gamete
contains one unit. Mendel's "unit" is now referred to as a - ANSWERSgene
Different forms of a gene are called - ANSWERSalleles
At a certain locus of the human genome, 200 different alleles exist in the population.
Each person has at most ___ alleles - ANSWERS2
Which statement about an individual that is homozygous for an allele is false? -
ANSWERSIts parents were necessarily homozygous for that allele
,In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short
plants and the F1 plants, which are all tall, are allowed to self-pollinate. What fraction of
the F2 generation are both tall and heterozygous? - ANSWERS1/2
Which statement about the inheritance of shell shape in tortoises is most likely to be
correct, given your genetic analysis of the tortoise family? - ANSWERSRound is
dominant to lumpy
Which statement about the inheritance of footedness in tortoises is most likely to be
correct, given your genetic analysis of the tortoise family? - ANSWERSBig and small
are codominat
If big feet (B) in tortoises is dominant to small feet (b), which of the following is the
genotype of the big-footed parent with respect to the foot gene? - ANSWERSBb
The physical appearance of a character is called - ANSWERSthe phenotype
A pea plant with red flowers is test crossed, and one-half of the resulting progeny have
red flowers, while the other half has white flowers. Therefore, the genotype of the test-
crossed parent was - ANSWERSRr
A particular genetic cross in which the individual in question is crossed with an
individual known to be homozygous for a recessive trait is referred to as a -
ANSWERStest cross
Which statement about a test cross is false? - ANSWERSIf the test individual is
homozygous, the progeny will have a 3:1 ratio
In a __ cross, genes for two different characters separate. - ANSWERSdihybrid
In garden peas, the alleles for tall plants is dominant over the allele for short plants. A
true-breeding tall plant is crossed with a short plant, and one the their offspring is test
crossed. Out of 20 offspring resulting resulting from the test cross, about __ should be
tall. - ANSWERS10
The genotype of an organism that expresses a dominant trait can be determined by -
ANSWERScrossing the organism with a homozygous recessive organism
In mice, short hair is dominant to long hair. If a short-haired individual is crossed with a
long-haired individual and both long- and short-haired offspring result, one can conclude
that - ANSWERSthe short-haired parent is heterozygous
Classical albinism results from a recessive allele. Which of the following is the expected
ratio for the progeny when a normally pigmented male with a albino father has children
with an albino woman? - ANSWERS1/2 normal, 1/2 albino
, Which of the following statements about a dihybrid cross is true? - ANSWERSIt is a
cross between identical double heterozygotes
Mendel's dihybrid crosses - ANSWERSAll of the above
In cocker spaniels, black color (B) is dominant over red (b), and solid color (S) is
dominant over spotted (s). If the genes are unlinked, and the offspring of BBss and bbss
individuals are mated with each other, what fraction of the next generation will be black
and spotted? - ANSWERS3/4
In humans, a widow's peak is caused by a dominant allele (W), and a continuous
hairline is caused by a recessive allele (w). Short fingers are caused by a dominant
allele (S), and long fingers are caused by a recessive allele (s). Suppose a woman with
a continuous hairline and short fingers and a man with a widow;s peach and long
fingers have three children. One child has short fingers and a widow's peak, one has
long fingers and a widow's peak, and one has long fingers and a continuous hairline.
What are the genotypes of the parents? - ANSWERSFemale wwSs, male Wwss
In dogs, phenotype A is caused by dominant alleles; phenotype B is caused by
recessive alleles. A dog that is homozygous for both traits of phenotype A is mated to a
dog with phenotype B. If the genes for the two traits are unlinked, which of the following
is the expected F1 phenotypic ratio? - ANSWERS1:0
Segregation of alleles occurs - ANSWERSduring gamete formation
Separation of the alleles of a single gene into different gametes is called -
ANSWERSsegregation
One of the major contributions of Mendel to the study of genetics was - ANSWERSthe
use of a quantitative approach to analyze data
Mendel performed a cross between individuals heterozygous for three different traits:
green versus yellow seeds, red versus white flowers, and green versus yellow pods.
What fraction of the offspring would have been expected to have green seeds, red
flowers and green pods? - ANSWERS27/64
Genetic mutations are - ANSWERSAll of the above
The particular allele of a gene that is present in most individuals in nature is referred to
as - ANSWERSwild type
Which of the following statements about Mendelian genetics is false? - ANSWERSIn
any population, only two alleles can exist for a given gene.
What percent of the progeny are likely to be albino? - ANSWERS50 percent
