Genetics Review
Biology CP
Genetics Review
Directions: To help you prepare for your upcoming test, complete each of the activities
described below. Be sure to carefully read and follow all instructions! Each activity should take
approximately 5-10 minutes, and you should start by completing the question below.
Warm-up Question: As you think about our study of Genetics, what is one thing that you
feel you understand well? What is one thing you are still confused about?
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Activity #1: Karyotyping
A karyotype is a picture of a persons chromosomes, arranged in homologous pairs. Karyotypes
are often helpful in diagnosing genetic disorders. In this activity, you will analyze two
karyotypes to determine whether or not they have a genetic disorder.
1. Look at each of the karyotypes shown below. Analyze each one to answer the questions.
Male or Female? _____________
Disorder (if any) ______________________
Explain how you knew if your patient was male or female
and how you identified their disorder
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Male or Female? _____________
Disorder (if any) ______________________
Explain how you knew if your patient was male or female
and how you identified their disorder
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_________________________________________________
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Genetics Review
Biology CP
Activity #2: Make Your Own Punnett Squares
We’ve been working hard to solve lots of Punnett Square problems, but now it is time to make
your own!
1. Create and write 2-3 Punnett Square problems of your own – try to make different types
of problems.
2. Solve your own problems, preferably on another sheet of paper.
3. Trade problems with one other person in your group – remember, don’t give your partner
your answer key!
4. Solve at least one of your partner’s problems (time permitting).
5. Use the answer keys you made to check each other’s work.
6. Finally, staple the problems and answer key that you wrote to this paper.
Activity #3: Pedigree Analysis
As you know, pedigree charts are important for tracking the inheritance of a trait over several
generations. Follow these instructions:
1. Read the following pedigree problem. Working on your own, draw the pedigree
described, and answer the questions. Sally married George, and they had 3 children,
Kathleen, Joe, and Jeremy. Jeremy was colorblind. Kathleen married Fred, and they
had three sons, John, Tom, and Richard. Richard and Tom are both colorblind as
well.
2. What type of inheritance is shown in this pedigree? How do you know?
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3. What can you conclude about Kathleen and Sally? ____________________________
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4. Compare your pedigree with your group members and discuss the answers to your
questions.
Genetics Review
Biology CP
Activity #4: Practice with Punnett Squares!
We can all use a little more practice with our Punnett Square problems – enjoy! Complete the
Punnett Square problems on your own sheet of paper. Be sure to show all of your work, and
give genotype and phenotype ratios! Staple your answers to this sheet when finished.
1. The gene for brown eyes is dominant to the gene for blue eyes. What is the chance that a
heterozygous brown-eyed father and a blue-eyed mother will have a blue-eyed child?
2. In pea plants, tall is dominant and short is recessive. Also, purple flower color is
dominant to white flower color. Cross two parents that are each heterozygous for both
traits.
3. When a homozygous red-flowered snapdragon is bred with a homozygous whiteflowered snapdragon, all of the offspring have pink flowers. Cross two pink
snapdragons.
4. The trait for Red-Green Colorblindness is sex-linked and recessive. What is the chance
that a colorblind male and a heterozygous female will produce a colorblind child?
5. David is homozygous for Type B blood. His wife, Sarah, is heterozygous for Type A
blood. What is the chance that they will have a child with Type O blood?
6. In certain types of cattle, crossing a homozygous red-haired cow with a homozygous
white-haired cow produces a coat color known as roan. Roan cattle actually have
separate white hairs and red hairs in their coat. Cross a roan cow with a red cow.
Activity #5: Genetic Disorders
Thanks to our recent Genetic Disorders presentations, you are now familiar with a variety of
genetic disorders; now you get to put this knowledge to use! For each description, write the
letter of the matching genetic disorder.
1. ______ Recessive disorder that results
from the absence of an enzyme required to
break lipids down; usually results in death in
childhood.
2. ______ Lethal genetic disorder, caused
by a dominant allele, that results in brain
deterioration and eventually death;
symptoms usually appear between ages 3050.
3. ______ Recessive disorder that results in
the accumulation of thick mucus in the lungs
and digestive system.
4. ______ Sex-linked and recessive
disorder in which the afflicted person lacks
clotting factors and may experience
excessive bleeding.
5. ______Caused by having an extra 21st
chromosome Trisomey-21).
6. _______Sex-linked disorder in which the
afflicted individual lacks the muscle protein
dystrophin, causing muscle deterioration and
eventually death.
7. ______ A codominant disorder that
results in misshapen red blood cells.
8. ______ Affected individuals do not
properly see colors (such as Red & Green)
9. ______ Recessive disorder that results
from an absence of an enzyme required to
break down a certain type of amino acid; can
result in damage to brain and nerve cells is
not treated
a. Color-blindness
b. Cystic Fibrosis
c. Tay-Sachs Disease
d. Huntington’s Disease
e. Phenylketonuria
f. Sickle Cell Anemia
g. Down Syndrome
h. Hemophilia
i. Duchenne Muscular Dystrophy
Genetics Review
Biology CP
Activity #6: Vocabulary Review
As always, there is a significant amount of vocabulary that you’ll need to review for your test.
Complete the activity below to help you get started!
Chapter 11: Complex Inheritance and Human Genetics
Directions: Fill in each blank in the statements below with the correct word from the word bank
below. You will use each of the words once.
autosomes
carrier
codominance
epistasis
incomplete dominance
karyotype
multiple alleles
pedigree
polygenic trait
nondisjunction
sex chromosomes
sex-linked trait
telomere
1. A(n) ________________________ shows an individual’s family tree and is a graphic
representation of genetic inheritance.
2. Some genes are located in sex chromosomes. A(n) ______________________ is a trait that
is controlled by these genes.
3. In humans, the 22 pairs of matching homologous chromosomes found in both males and
females are called _______________________.
4. Traits controlled by more than two alleles are said to have ______________________.
5. An individual who is heterozygous, or has a recessive allele for an undesirable trait, and does
not actually express the trait, is called a(n) __________________.
6. In __________________________, the phenotype of the heterozygous individual is a blend
between the two homozygous individuals.
7. ______________________ are chromosomes that determine the sex of an individual.
8. ______________________ causes both phenotypes to be observed in equal amounts at the
same time in the heterozygous individual.
9. The interaction between alleles in which one allele hides the effect of another allele, such as
the alleles that produce coat color variations in Labrador retrievers, is known as
__________________________ .
10. A(n) _______________________ is a chart of an individual’s chromosomes, and it is useful
in identifying unusual numbers of chromosomes in cells.
11. A(n)_____________________________ is a trait that is controlled by two or more genes,
such as skin color and height in humans.
12. A protective “cap” made of DNA that is found on the ends of a chromosome is called a(n)
______________________________.
13. _______________________________ occurs as a result of sister chromatids that do not
separate properly during cell division, resulting in gametes with an abnormal number of
chromosomes.
Genetics Review
Biology CP
Section 10.2-10.3: Genetics and Heredity
Matching: Write the letter of the term that best corresponds with each

definition in the space provided.
a. Allele
_______1. The new combination of genes provided by crossing over
b. Dominant
and independent assortment during meiosis.
_______2. Mendel’s law that states that a random distribution of alleles c. Genetic recombination
d. Genetics
occurs during gamete formation due to the fact that genes on
e. Genotype
separate chromosomes sort independently during meiosis.
f. Heterozygous
_______3. Another term to describe organisms that are
g. Homozygous
heterozygous; they have two different alleles for a trait.
h. Hybrid
_______4. The study of or science of heredity.
i. Law of segregation
_______5. An alternative form of a single gene
j. Law of independent assortment
_______6. The occurrence of one or more extra sets of all
k. Phenotype
chromosomes in an organism.
l. Polyploidy
_______7. An organism with two of the SAME allele.
_______8. An organism with two different alleles for a particular trait. m. Recessive
_______9. The form of a trait that “masks” or hides the other trait.

_______10. An organism’s allele pairs or gene combination.
_______11. The trait that is “masked” or hidden by another trait.
_______12. The observable characteristic or outward expression of a trait.
_______13. Mendel’s law that states that the two alleles for each trait separate during meiosis.