PCB 3063 GENETICS EXAM QUESTIONS WITH ANSWERS
SUCCESS GAURANTEED A+ 2023 UPDATE
Quizzes:
Canvas Quiz 1
The science of genetics is concerned with
All of the above are correct (the transmission of traits, the origin of heritable differences,
the distribution of heritable characteristics in populations, the expression of genetic
information)
Of the following human diseases, which provides the best example of the interplay between
genes and the environment?
Phenylketonuria
Canvas Quiz 2
An individual with the O blood group produces antibodies against the
A and B antigens
If William crosses two true-breeding pea strains of the genotype “RR” and genotype “rr”
and observes the F1 progeny using microscopic techniques to analyze the starch granules
within each strand, the ratio of seeds of kind A (RR with maximum starch), B (Rr
heterozygotes with intermediate amounts of starch), C (rr homozygotes with minimal
starch) would be:
0:1:0
The Manx phenotype in cats is caused by a dominant allele that is lethal in the
homozygous state during embryonic stages. A Manx cat is crossed to another Manx cat.
What is the expected outcome for the surviving offspring?
2 Manx: 1 normal
A man with blood type A (his father was blood type O) has a child with a woman with
blood type B (her father was blood type O). What was the possible blood types for the
child?
A, B, AB, and O
A situation where a disease may be caused by mutations in two or more different genes is
called .
The phenomenon in which a single gene affects a number of seemingly unrelated
characters is known as .
Locus heterogeneity, Pleiotropic effect
,PCB 3063 GENETICS EXAM QUESTIONS WITH ANSWERS
SUCCESS GAURANTEED A+ 2023 UPDATE
In a typical Mendelian diploid cross, (AaBb x AaBb), what is the expected proportion of
progeny that are aaB_ : A_B_ : A_bb :aabb
3:9:3:1
A person with type AB blood has a while with a person with type AB blood. What are the
possible blood types of the child?
Either A, B, or A
A baby has type AB blood. If the mother has blood type A, what are the possible blood
groups for the father?
B or AB
The Bombay blood group is very rare and is associated with the lack of production of the
complete H substance that is the starting material for the production of both the A antigen
as well as the B antigen. Since these individuals lack the antigen A, B and H, they will
make antibodies against all three antigens. They are mistakenly typed as O because the
RBC’s are not agglutinated by addition of Anti-A or Anti-B serum in lab tests. Routine
lab tests do not test for the H antigen. A person with the blood type O lacks both A and B
antigens. However, a person with blood group O has the H substance. Therefore, when a
person having the Bombay blood group (genotype hh) receives blood from a person of O
blood group:
The anti-H antibody in his serum will agglutinate the donor RBC’s that contain the H
antigen
Two alleles of a gene are P and p. The allele “P” confers a peacock feather phenotype to
parrots whereas the recessive “p” phenotype allele shows normal coloration of the
feathers. You cross two heterozygous parrots Pp both with peacock to obtain progeny in
the following numbers for each phenotype:
PP = 0 Pp = 132 pp = 65
Therefore, the allele “P” is most likely a:
Lethal allele
Two alleles of a gene are A and a. You cross two heterozygous parents Aa to obtain
progeny in the following numbers:
AA = 240 Aa = 485 aa = 45
Therefore, the allele “a” is best described as
a: Semi-lethal allele
,PCB 3063 GENETICS EXAM QUESTIONS WITH ANSWERS
SUCCESS GAURANTEED A+ 2023 UPDATE
The two alleles for flower colors in four-o’clock plants C^R and C^W show incomplete
dominance. A pink-flowered four-o’clock plant (C^R C^W) is crossed to a white-
flowered plant (C^W C^W) . What is the expected outcome for the offspring?
0 red: 1 pink: 1 white
The MN system of blood groups is an example of:
Codominance
You are expected to arrange the unordered steps (a-f) in a normal individual using the
options given below beginning at the first step (DNA) and finishing at the consequence.
a. Normal beta-globin gene
b. Disk shaped Red blood cell carrying normal oxygen
c. Healthy individual
d. Normal beta-globin mRNA
e. Normal beta-globin polypeptide
f. Incorporated into a normal hemoglobin protein tetramer
a-d-e-f-b-c
If an animal with temperature sensitive alleles is lethal only in certain temperature
ranges, the alleles are referred to as .
Conditional lethal alleles
If a heterozygote possesses a phenotype intermediate to the phenotypes of homozygous
dominant and homozygous recessive genotypes, then we are dealing with the case of
.
Incomplete dominance
In rabbits, full coat color ( c ) is the dominant trait. A second allele, chinchilla ( cch ) is
recessive for full coat color. Himalayan coat color ( ch ) is recessive to chinchilla and full
coat colors, and albino ( c ) is recessive to all coat colors. If two chinchilla rabbits’ mate,
what coat color is not possible in their offspring?
Full coat color
Homozygosity of the sickle cell allele causes sickle cell anemia, whereas heterozygotes
show .
Heterozygous advantage
, PCB 3063 GENETICS EXAM QUESTIONS WITH ANSWERS
SUCCESS GAURANTEED A+ 2023 UPDATE
If an allele is dominant in one sex and recessive in another, it is an example of .
Sex-influenced inheritance
Epistasis is the phenomenon .
When one gene can mask the expression of a second gene
You conduct a gross between heterozygous parents when you expect 9:3:3:1 phenotypic
ratio in the offspring but observe a ratio of 9:7. What explains this observation?
Epistatic interaction of the two genes
Two parents both display the same kind of recessive phenotype, however when they
produce offspring, the offspring show wild-type phenotype. What phenomenon does this
represent?
Complementation
Presence of absence of scurs is an example of sex-influenced inheritance in cattle. A
heterozygous male will have and a heterozygous female will have .
Scurs, no scurs
Blending of phenotypes, not genotypes is seen incomplete dominance.
True
A female Manx cat is mated to a male Manx cat to produce offspring. The probability that
the kitten has a non-manx tail is:
1/3
Both alleles make functional gene products which are expression simultaneously in
codominance.
True
In sex influenced traits, both sexes can express the trait, depending on their genotype, but
in sex limited inheritance a particular sex can only have one phenotype for that trait in
question.
True
SUCCESS GAURANTEED A+ 2023 UPDATE
Quizzes:
Canvas Quiz 1
The science of genetics is concerned with
All of the above are correct (the transmission of traits, the origin of heritable differences,
the distribution of heritable characteristics in populations, the expression of genetic
information)
Of the following human diseases, which provides the best example of the interplay between
genes and the environment?
Phenylketonuria
Canvas Quiz 2
An individual with the O blood group produces antibodies against the
A and B antigens
If William crosses two true-breeding pea strains of the genotype “RR” and genotype “rr”
and observes the F1 progeny using microscopic techniques to analyze the starch granules
within each strand, the ratio of seeds of kind A (RR with maximum starch), B (Rr
heterozygotes with intermediate amounts of starch), C (rr homozygotes with minimal
starch) would be:
0:1:0
The Manx phenotype in cats is caused by a dominant allele that is lethal in the
homozygous state during embryonic stages. A Manx cat is crossed to another Manx cat.
What is the expected outcome for the surviving offspring?
2 Manx: 1 normal
A man with blood type A (his father was blood type O) has a child with a woman with
blood type B (her father was blood type O). What was the possible blood types for the
child?
A, B, AB, and O
A situation where a disease may be caused by mutations in two or more different genes is
called .
The phenomenon in which a single gene affects a number of seemingly unrelated
characters is known as .
Locus heterogeneity, Pleiotropic effect
,PCB 3063 GENETICS EXAM QUESTIONS WITH ANSWERS
SUCCESS GAURANTEED A+ 2023 UPDATE
In a typical Mendelian diploid cross, (AaBb x AaBb), what is the expected proportion of
progeny that are aaB_ : A_B_ : A_bb :aabb
3:9:3:1
A person with type AB blood has a while with a person with type AB blood. What are the
possible blood types of the child?
Either A, B, or A
A baby has type AB blood. If the mother has blood type A, what are the possible blood
groups for the father?
B or AB
The Bombay blood group is very rare and is associated with the lack of production of the
complete H substance that is the starting material for the production of both the A antigen
as well as the B antigen. Since these individuals lack the antigen A, B and H, they will
make antibodies against all three antigens. They are mistakenly typed as O because the
RBC’s are not agglutinated by addition of Anti-A or Anti-B serum in lab tests. Routine
lab tests do not test for the H antigen. A person with the blood type O lacks both A and B
antigens. However, a person with blood group O has the H substance. Therefore, when a
person having the Bombay blood group (genotype hh) receives blood from a person of O
blood group:
The anti-H antibody in his serum will agglutinate the donor RBC’s that contain the H
antigen
Two alleles of a gene are P and p. The allele “P” confers a peacock feather phenotype to
parrots whereas the recessive “p” phenotype allele shows normal coloration of the
feathers. You cross two heterozygous parrots Pp both with peacock to obtain progeny in
the following numbers for each phenotype:
PP = 0 Pp = 132 pp = 65
Therefore, the allele “P” is most likely a:
Lethal allele
Two alleles of a gene are A and a. You cross two heterozygous parents Aa to obtain
progeny in the following numbers:
AA = 240 Aa = 485 aa = 45
Therefore, the allele “a” is best described as
a: Semi-lethal allele
,PCB 3063 GENETICS EXAM QUESTIONS WITH ANSWERS
SUCCESS GAURANTEED A+ 2023 UPDATE
The two alleles for flower colors in four-o’clock plants C^R and C^W show incomplete
dominance. A pink-flowered four-o’clock plant (C^R C^W) is crossed to a white-
flowered plant (C^W C^W) . What is the expected outcome for the offspring?
0 red: 1 pink: 1 white
The MN system of blood groups is an example of:
Codominance
You are expected to arrange the unordered steps (a-f) in a normal individual using the
options given below beginning at the first step (DNA) and finishing at the consequence.
a. Normal beta-globin gene
b. Disk shaped Red blood cell carrying normal oxygen
c. Healthy individual
d. Normal beta-globin mRNA
e. Normal beta-globin polypeptide
f. Incorporated into a normal hemoglobin protein tetramer
a-d-e-f-b-c
If an animal with temperature sensitive alleles is lethal only in certain temperature
ranges, the alleles are referred to as .
Conditional lethal alleles
If a heterozygote possesses a phenotype intermediate to the phenotypes of homozygous
dominant and homozygous recessive genotypes, then we are dealing with the case of
.
Incomplete dominance
In rabbits, full coat color ( c ) is the dominant trait. A second allele, chinchilla ( cch ) is
recessive for full coat color. Himalayan coat color ( ch ) is recessive to chinchilla and full
coat colors, and albino ( c ) is recessive to all coat colors. If two chinchilla rabbits’ mate,
what coat color is not possible in their offspring?
Full coat color
Homozygosity of the sickle cell allele causes sickle cell anemia, whereas heterozygotes
show .
Heterozygous advantage
, PCB 3063 GENETICS EXAM QUESTIONS WITH ANSWERS
SUCCESS GAURANTEED A+ 2023 UPDATE
If an allele is dominant in one sex and recessive in another, it is an example of .
Sex-influenced inheritance
Epistasis is the phenomenon .
When one gene can mask the expression of a second gene
You conduct a gross between heterozygous parents when you expect 9:3:3:1 phenotypic
ratio in the offspring but observe a ratio of 9:7. What explains this observation?
Epistatic interaction of the two genes
Two parents both display the same kind of recessive phenotype, however when they
produce offspring, the offspring show wild-type phenotype. What phenomenon does this
represent?
Complementation
Presence of absence of scurs is an example of sex-influenced inheritance in cattle. A
heterozygous male will have and a heterozygous female will have .
Scurs, no scurs
Blending of phenotypes, not genotypes is seen incomplete dominance.
True
A female Manx cat is mated to a male Manx cat to produce offspring. The probability that
the kitten has a non-manx tail is:
1/3
Both alleles make functional gene products which are expression simultaneously in
codominance.
True
In sex influenced traits, both sexes can express the trait, depending on their genotype, but
in sex limited inheritance a particular sex can only have one phenotype for that trait in
question.
True
