Genetics Study Guide
Test is on _____________________________________
Vocabulary: Match the terms on the left with its definition on the right. Some terms will be used more than one
time.
G_1. trait
A. trait that shows in a hybrid
B_2. hybrid
B. the alleles for a gene are different
E_3. genetics
C. version of a gene
H_4. pure
D. physical appearance of an individual
A__5. dominant
E. the study of inheritance
F__6. recessive
F. trait that is masked in a hybrid
H__7. homozygous
G. characteristic that is passed to offspring from parents
B__8. heterozygous
H. the alleles for a gene are the same
C__9. allele
I. genetic makeup of an individual
I__10. genotype
D__11. phenotype
Genetic Inheritance: Match the term on the left with the description on the right.
D__12. Mendelian genetics
A. more than one gene pair involved in trait
B__13. Incomplete dominance
B. a new, third phenotype is produced in offspring
E__14. Codominance
C. a cross comparing one trait
A__15. Multiple Alleles
D. dominant masks recessive
F__16. Sex-Linked
E. both alleles express themselves fully (equally)
C__17. Monohybrid Cross
F. genes associated with the X chromosome
Determining Inheritance Patterns: Match the example or description on the left with the inheritance pattern on the
right.
B__18. white flower (WW) x red flower (RR) = pink flower (WR)
A. Mendelian
A__19. yellow pea (YY) x green pea (yy) = yellow pea (Yy)
B. Incomplete
C,D_20. Type A blood (AA) x Type B blood (BB) = Type AB blood (AB)
C. Codominance
A__21. AABBCCDD (most dominant) &aabbccdd (most recessive)
D. Multiple Alleles
C,D_22. Type A blood (AO) x Type B blood (BO) = Type O blood (OO)
E. Sex- Linked
E__23. XX x XY = XX or XY
E__24. Hemophilia
A__25. PKU
Identifying Human Genetic Disorders: Match the example or description on the left with the inheritance pattern on
the right. Determine the type of inheritance pattern.
Definition
D__26. Genetic disease in which the
blood fails to clot.
E__27. Genetic disease in which the
blood cell is sickle-shaped. Leads to
anemia.
F__28. Genetic disease caused by an
extra 21st chromosomes
B__29. Disorder that causes inability to
break down phenylalanine
C__30. Disease that leads to breakdown
of the nervous system
A__31. Genetic disease that leads to
mucous build-up in the lungs
Disorder/Disease Name
a. Cystic fibrosis
Dominant, Recessive, Sex-linked,
or Chromosomal? (first column)
Sex-linked recessive
b. PKU
Codominance
c. Huntington’s Disease
Chromosomal aneuploidy
d. Hemophilia
Autosomal recessive
e. Sickle cell disease
Autosomal dominant
f.
Autosomal recessive
Down Syndrome
Mendelian Laws of Genetics: Distinguish between Mendel’s three laws of genetics. Write the name of the law in the
space provided.
Law of Dominance
32. In a hybrid individual, a dominant “factor” will mask a recessive “factor.”
Law of Segregation
33. Genetic “factors” separate when gametes form.
Law of Independent Assortment 34. Genetic “factors” are inherited independently of one another after gamete
formation.
35. Albinism is a recessive trait in humans. A normal woman and a normal man have a child that is albino.
a) What are the possible genotypes of a parent who is normal? AA or Aa
b) Using a Punnett square, explain how two normal parents have a child with a recessive trait.
Both parents would be Aa
Punnett Squares: Use the information in the list below to determine the genotype, phenotype, and probabilities
associated with the following Punnett Squares.
G = green pea pod
B = black fur
P = purple flower
g = yellow pea pod
Y = yellow fur
W = white flower
(Type of Inheritance: Mendelian)
(Type of Inheritance: Co-dominance)
(Type of Inheritance: Incomplete dominance)
36. A geneticist decides to cross a pure bred green pea pod pea plant with a pure bred yellow pea pod plant. What are
the genotypes, phenotypes, and probabilities for the offspring of this cross?
Key: G=green g=yellow
Cross: GGxgg
37. Two dogs in your neighborhood mated and produced a litter of puppies. The male dog has black fur and the female
dog has yellow fur. What are the genotypes, phenotypes, and probabilities for the offspring of this cross?
Parents: BBxYY 100% of the offspring will be BY (black and yellow)
38. You notice something odd happening in your flower bed. You have a dark purple set of pansies planted next to a set
of white pansies. Between these two sets of pansies, a new color of flower has grown and looks to be intermediate in
color between both of the two original plant sets. If a dark purple pansy was allowed to fertilize a white pansy, what
would be genotypes, phenotypes, and probabilities for the offspring of this cross?
Parents: PP x WW
100% of the offspring will be PW (light purple)
39. Use your knowledge of blood typing to help you answer the following question. If two parents have type B blood,
can they have a child who has type O blood? Use a punnett square to show how this could or could not be possible.
Yes, both would be BO
40. Use your knowledge of sex-linked inheritance to help you answer the following question. Hemophilia is a sex-linked
trait. If a mother who is a carrier for hemophilia has children with a man who has hemophilia, what would be the
genotypes, phenotypes, and probabilities for their offspring?
Parents: XHXh x XhY
41. In humans, there are _22_ pairs of autosomes and ___1__ pairs of sex chromosomes. That means, humans have a
total of __23___ pairs of chromosomes or ___46___ chromosomes total.
42. A couple has been very blessed with five sons. The wife discovers she is pregnant for a sixth time. What is the
probability (chance) that this child will be a daughter? 50%
Answer the questions below based on the karyotype provided.
43. What is the gender of this individual?
Male
44. How many pairs of chromosomes does a normal human
have?
23
45. Where would the extra chromosome be located if this person
had Down Syndrome?
21st chromosome
46. Who is the “Father of Genetics” and what plant did he study?
Mendel; peas
Answer the questions below based on the pedigree provided.
47. Does this pedigree show a dominant trait or a
recessive trait? How do you know?
Autosomal Recessive, there are carriers and some
are male carriers, which means it can’t be sex-linked
recessive.
48. How many generations are shown in the
pedigree? 3
49. How many people are affected by this disorder?
2
50. How many children did the couple in generation two have?
3
51. What does it mean for a symbol to be half-filled?
carrier
52. Write the genotype for each individual:
I-1: _Hh___
II-1: ___Hh__
III-1: __hh___
I-2: _Hh____
II-2: ___Hh__
III-2: __HH or Hh___
II-3: ____hh_
III-3: __HH or Hh__
II-4: __HH or Hh_
III-4: ___Hh__
III-5: ___Hh__
III-6: ___Hh__
53. In the boxes, fill in the alleles that would make each genotype heterozygous:
A
a
b
B
C
c