Genetics Final Exam: Expert-Verified Questions
from World-Class Academics with Comprehensive
Explanations and Solutions
Cystic fibrosis is an autosomal recessive disorder that affects lung function in humans. If a
couple, who are both unaffected, have an affected child, what is the probability their next
child will be an affected girl? - CORRECT ANSWER- -1/8
Cystic fibrosis is an autosomal recessive disorder that affects lung function in humans. A
man and a woman are both unaffected heterozygous carriers of a cystic fibrosis gene. If the
couple has two children, what is the probability that their first child will be unaffected and
their second child will be unaffected? - CORRECT ANSWER- -56.25%
Suppose that we are dealing with four genes, each gene consisting of a dominant allele
(capital letter) and a recessive allele (small case letter). If the cross CcMmLlPP X
CCmmLlpp is made, what is the probability of obtaining an individual who is CcmmLLPp? -
CORRECT ANSWER- -1/16
Consider a nondebilitating hereditary condition in humans. If two affected parents produce
an unaffected daughter, then the allele responsible for the condition must be - CORRECT
ANSWER- -autosomal dominant
A researcher is studying a pedigree of a family afflicted by an unknown disease. He notices
that every generation depicted in the pedigree demonstrates at least one afflicted
individual. Furthermore, both males and females in the pedigree can demonstrate this
disease, and both sexes can pass this disease to progeny (either daughters or sons). The
researcher is most likely studying a(n) - CORRECT ANSWER- -autosomal dominant disorder
A young man's family is afflicted by red-green color blindness. He decides to draw a
pedigree of his family detailing the inheritance of this condition, and notices that—in his
family—only he and his grandfather demonstrate red-green color blindness. Furthermore,
none of his aunts or uncles has this condition, and his brother can distinguish between red
,and green. Red-green color blindness is most likely a(n) - CORRECT ANSWER- -X-linked
recessive disorder
A scientist is very interested in the SRY gene in humans, which is involved in male sex
determination and which is never found on X chromosomes (i.e., this gene occurs in the
"differential" region of the Y chromosome). SRY is an example of a _______________ gene. -
CORRECT ANSWER- -hemizygous
What is the probability that Princess Irene is a carrier? - CORRECT ANSWER- -50%
Mendel found that full pea pods (F) are dominant over constricted pods (f), while round
seeds (R) are dominant over wrinkled seeds (r).
In one cross, involving parent plants of unknown genotype and phenotype, the following
offspring were obtained.
3/8 full, round3/8 full, wrinkled1/8 constricted, round1/8 constricted, wrinkled
Determine the genotype and phenotype of the parents. - CORRECT ANSWER- -FfRr (Full,
Round) and Ffrr (Full, wrinkled)
You are a researcher examining the expression pattern of a wobbly fly phenotype. You have
flies that fly straight and those having a wobble flight. When you cross a straight flying strain
with a strain showing a wobble flight, all the F1 flies fly straight.
In the F2 generation, you get 762 straight flying flies and 238 wobbly flies. Your null
hypothesis is that one gene controls flight patterns and that straight is dominant to wobbly.
Use chi square analysis to test your hypothesis.
(a) What is your chi square number? Submit your answer as it is.
(b) Do you reject or fail to reject the null hypothesis? Submit your answer either "reject" or
"fail to reject" - CORRECT ANSWER- -(a) 0.768
, (b) fail to reject
In tomatoes, yellow flowers (Y) are dominant to white flowers (y) and round fruit (R) is
dominant to oblong fruit (r). You cross a heterozygous yellow round plant with a plant with
white flowers and oblong fruit.
238 yellow round210 yellow oblong270 white round282 white oblong
chi-square value =
statistical decision = - CORRECT ANSWER- -12.672
reject
A husband and wife have normal vision, although both of their fathers are red-green color-
blind, an inherited X-linked recessive condition. What is the probability that their first child
will be (a) a normal son? (b) a normal daughter? (c) a color-blind son? (d) a color-blind
daughter? Submit your answer as a decimal (e.g., 2/4 = 0.5, 4/4 = 1, 0/4 = 0). - CORRECT
ANSWER- -(a) 0.25
(b) 0.5
(c) 0.25
(d) 0
(a) What is the probability of the trait appearing in offspring if 7 should marry 9?
from World-Class Academics with Comprehensive
Explanations and Solutions
Cystic fibrosis is an autosomal recessive disorder that affects lung function in humans. If a
couple, who are both unaffected, have an affected child, what is the probability their next
child will be an affected girl? - CORRECT ANSWER- -1/8
Cystic fibrosis is an autosomal recessive disorder that affects lung function in humans. A
man and a woman are both unaffected heterozygous carriers of a cystic fibrosis gene. If the
couple has two children, what is the probability that their first child will be unaffected and
their second child will be unaffected? - CORRECT ANSWER- -56.25%
Suppose that we are dealing with four genes, each gene consisting of a dominant allele
(capital letter) and a recessive allele (small case letter). If the cross CcMmLlPP X
CCmmLlpp is made, what is the probability of obtaining an individual who is CcmmLLPp? -
CORRECT ANSWER- -1/16
Consider a nondebilitating hereditary condition in humans. If two affected parents produce
an unaffected daughter, then the allele responsible for the condition must be - CORRECT
ANSWER- -autosomal dominant
A researcher is studying a pedigree of a family afflicted by an unknown disease. He notices
that every generation depicted in the pedigree demonstrates at least one afflicted
individual. Furthermore, both males and females in the pedigree can demonstrate this
disease, and both sexes can pass this disease to progeny (either daughters or sons). The
researcher is most likely studying a(n) - CORRECT ANSWER- -autosomal dominant disorder
A young man's family is afflicted by red-green color blindness. He decides to draw a
pedigree of his family detailing the inheritance of this condition, and notices that—in his
family—only he and his grandfather demonstrate red-green color blindness. Furthermore,
none of his aunts or uncles has this condition, and his brother can distinguish between red
,and green. Red-green color blindness is most likely a(n) - CORRECT ANSWER- -X-linked
recessive disorder
A scientist is very interested in the SRY gene in humans, which is involved in male sex
determination and which is never found on X chromosomes (i.e., this gene occurs in the
"differential" region of the Y chromosome). SRY is an example of a _______________ gene. -
CORRECT ANSWER- -hemizygous
What is the probability that Princess Irene is a carrier? - CORRECT ANSWER- -50%
Mendel found that full pea pods (F) are dominant over constricted pods (f), while round
seeds (R) are dominant over wrinkled seeds (r).
In one cross, involving parent plants of unknown genotype and phenotype, the following
offspring were obtained.
3/8 full, round3/8 full, wrinkled1/8 constricted, round1/8 constricted, wrinkled
Determine the genotype and phenotype of the parents. - CORRECT ANSWER- -FfRr (Full,
Round) and Ffrr (Full, wrinkled)
You are a researcher examining the expression pattern of a wobbly fly phenotype. You have
flies that fly straight and those having a wobble flight. When you cross a straight flying strain
with a strain showing a wobble flight, all the F1 flies fly straight.
In the F2 generation, you get 762 straight flying flies and 238 wobbly flies. Your null
hypothesis is that one gene controls flight patterns and that straight is dominant to wobbly.
Use chi square analysis to test your hypothesis.
(a) What is your chi square number? Submit your answer as it is.
(b) Do you reject or fail to reject the null hypothesis? Submit your answer either "reject" or
"fail to reject" - CORRECT ANSWER- -(a) 0.768
, (b) fail to reject
In tomatoes, yellow flowers (Y) are dominant to white flowers (y) and round fruit (R) is
dominant to oblong fruit (r). You cross a heterozygous yellow round plant with a plant with
white flowers and oblong fruit.
238 yellow round210 yellow oblong270 white round282 white oblong
chi-square value =
statistical decision = - CORRECT ANSWER- -12.672
reject
A husband and wife have normal vision, although both of their fathers are red-green color-
blind, an inherited X-linked recessive condition. What is the probability that their first child
will be (a) a normal son? (b) a normal daughter? (c) a color-blind son? (d) a color-blind
daughter? Submit your answer as a decimal (e.g., 2/4 = 0.5, 4/4 = 1, 0/4 = 0). - CORRECT
ANSWER- -(a) 0.25
(b) 0.5
(c) 0.25
(d) 0
(a) What is the probability of the trait appearing in offspring if 7 should marry 9?
