Name: 
 

Genetics and Inheritance Final Exam Practice


Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 
The phenotypic ratio resulting from a dihybrid cross showing independent assortment  is expected to be
a.
9:1:1:3.
b.
1:2:1.
c.
3:1.
d.
9:3:3:1.
e.
3:9:9:1.
 

 2. 
A carrier of a genetic disorder who does not show symptoms is most likely to be __________ to transmit it to offspring.
a.
homozygous for the trait and unable
b.
homozygous for the trait and able
c.
heterozygous for the trait and able
d.
heterozygous for the trait and unable
e.
None of the choices are correct.
 

 3. 
Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes?
a.
dd and  dd
b.
DD and  dd
c.
DD and  DD
d.
Dd and  Dd
e.
None of the choices are correct.
 

 4. 
Imagine that beak color in a finch species is controlled by a single gene. You mate a finch homozygous for orange (pigmented) beak with a finch homozygous for ivory (unpigmented) beak and get numerous offspring, all of which have a pale, ivory-orange beak. This pattern of color expression is most likely to be an example of
a.
pleiotropy.
b.
crossing over.
c.
codominance.
d.
polygenic inheritance.
e.
incomplete dominance.
 

 5. 
The expression of both alleles for a trait in a heterozygous individual illustrates
a.
blending inheritance.
b.
incomplete dominance.
c.
polygenic inheritance.
d.
pleiotropy.
e.
codominance.
 

 6. 
Genes located close together on the same chromosomes are referred to as __________ genes and generally __________.
a.
linked . . . do not sort independently during meiosis
b.
associated . . . sort independently during meiosis
c.
homologous . . . are inherited together
d.
linked . . . sort independently during meiosis
e.
codependent . . . do not sort independently during meiosis
 

 7. 
Crossing over __________ genes into assortments of __________ not found in the parents.
a.
combines unlinked . . . alleles
b.
recombines linked . . . alleles
c.
combines  linked . . . genes
d.
recombines unlinked . . . genes
e.
recombines unlinked . . . chromosomes
 

 8. 
What is the normal complement of sex chromosomes in a human male?
a.
two Y chromosomes
b.
one Y chromosome
c.
two X chromosomes and one Y chromosome
d.
two X chromosomes
e.
one X chromosome and one Y chromosome
 

 9. 
Any gene located on a sex chromosome
a.
will exhibit pleiotropy.
b.
is called a sex-linked gene.
c.
will exhibit codominance.
d.
is called a recessive gene.
e.
is called a dominant allele.
 
 
Use the picture below to answer the questions that follow
nar001-1.jpg
 

 10. 

The bell curve diagram shown above is typical of which type of inheritance pattern?
a.
incomplete dominance
b.
dominant/recessive inheritance
c.
sex-linked inheritance
d.
heterozygote advantage
e.
polygenic inheritance
 

 11. 
A locus is
a.
a recessive gene.
b.
an unmatched allele.
c.
a sex chromosome.
d.
the location of an allele on a chromosome.
e.
a dominant gene.
 

 12. 
Hybrid organisms produced from a cross between two pure-breeding organisms belong to which generation?
a.
P1
b.
H1
c.
A1
d.
F1
e.
F2
 

 13. 
If short hair (L) is dominant to long hair (l), animals LL and Ll have the same
a.
parents.
b.
genotypes.
c.
phenotypes.
d.
alleles.
e.
genes.
 

 14. 
Short hair (L) is dominant to long hair (l). If a short-haired animal of unknown origin is crossed with a long-haired animal and they produce one long-haired and one short-haired offspring, this would indicate that
a.
the short-haired animal was pure-breeding.
b.
the short-haired animal was not pure-breeding.
c.
the long-haired animal was not pure-breeding.
d.
the long-haired animal was pure-breeding.
e.
none of these can be determined with two offspring
 

 15. 
For monohybrid experiments, a testcross could result in which of the following ratios?
a.
1:1
b.
2:1
c.
9:3:3:1
d.
1:2:1
e.
3:1
 

 16. 
An individual with a genotype of Aa Bb CC is able to produce how many different kinds of gametes?
a.
2
b.
3
c.
4
d.
7
e.
8
 

 17. 
In cocker spaniels, black coat color (B) is dominant over red (b), and solid color (S) is dominant over spotted (s). If two dihybrids (Bb Ss) were crossed, the most common phenotype would be
a.
black and solid.
b.
black and spotted.
c.
red and solid.
d.
red and spotted.
e.
none of these
 

 18. 
In cocker spaniels, black coat color (B) is dominant over red (b), and solid color (S) is dominant over spotted (s). A cross of Bb Ss with bb ss would produce the phenotypic ratio
a.
9:3:3:1.
b.
1:1:1:1.
c.
1:2:1.
d.
3:1.
e.
none of these
 

 19. 
Coat color in one breed of mice is controlled by incompletely dominant alleles so that yellow and white are homozygous, while cream is heterozygous. The cross of two cream individuals will produce
a.
all cream offspring.
b.
equal numbers of white and yellow mice, but no cream.
c.
equal numbers of white and cream mice.
d.
equal numbers of yellow and cream mice.
e.
equal numbers of white and yellow mice, with twice as many creams as the other two colors.
 

 20. 
If a child belonged to blood type O, he or she could not have been produced by which set of parents?
a.
Type A mother and type B father
b.
Type A mother and type O father
c.
Type AB mother and type O father
d.
Type O mother and type O father
 

 21. 
A gene that produces multiple effects is called
a.
a multiple allele.
b.
an autosome.
c.
an epistatic gene.
d.
a pleiotropic gene.
e.
an incompletely dominant gene.
 

 22. 
Genes are
a.
located on chromosomes.
b.
inherited in the same way as chromosomes.
c.
arranged in linear sequence on chromosomes.
d.
assorted independently during meiosis.
e.
all of these
 

 23. 
DNA coding regions that affect the same trait are called
a.
homologues.
b.
alleles.
c.
autosomes.
d.
loci.
e.
gametes.
 

 24. 
Which of the following designates a normal human female?
a.
XXY
b.
XY
c.
XX
d.
XYY
e.
XO
 

 25. 
If alleles L, M, and N are on the maternal chromosome and l, m, and n are on the paternal chromosome, the only way that a gamete from a heterozygote will produce a gamete with alleles l, m, and N is through
a.
nondisjunction.
b.
the laws of segregation.
c.
the law of independent assortment.
d.
crossing over.
e.
chromosome aberration.
 

 26. 
A colorblind man and a woman with normal vision whose father was colorblind have a son. Colorblindness, in this case, is caused by an X-linked recessive gene. If only the male offspring are considered, the probability that their son is colorblind is
a.
.25 (or 25 percent).
b.
.50 (or 50 percent).
c.
.75 (or 75 percent).
d.
1.00 (or 100 percent).
 

 27. 
An X-linked carrier is a
a.
homozygous dominant female.
b.
heterozygous female.
c.
homozygous recessive female.
d.
homozygous male.
e.
heterozygous male.
 

 28. 
Nondisjunction involving the X chromosomes may occur during oogenesis and produce two kinds of eggs. If normal sperm fertilize these two types, which of the following pairs of genotypes are possible?
a.
XX and XY
b.
XXY and XO
c.
XYY and XO
d.
XYY and YO
e.
none of these
 
 
The following pedigree shows the inheritance of an autosomal genetic disorder inherited in simple Mendelian patterns.
nar002-1.jpg
 

 29. 
Determine if the genetic disorder is dominant or recessive.  Which individual can possibly be a NON-carrier of the allele causing the disorder.
a.
III
b.
V
c.
IX
d.
X
e.
All individuals above must have at least one copy of the affected allele.
 

 30. 
If (X) marries a woman that has the same genetic disorder his father had, what is the probability that his child will also have the disease?
a.
0%
b.
50%
c.
66.7%
d.
75%
e.
100%
 



 
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