Biology; Grade Level: 10
Duration: 55-minute period
Content Standards: NGSS HS-LS3-3. NGSS HS-LS3-2. CCSS.ELA-LITERACY.RST.910.3. CCSS.ELA-LITERACY.RST.9-10.7.
Prior Knowledge/Connections: Genes are passed from parents to offspring and contribute to
observable physical characteristics. Pedigrees are used to track genetic information.
Student Learning Objectives: Students will be able to analyze a pedigree and explain how a
genetic disorder gets passed down in a family. Students will also be able to construct a pedigree
of a trait that has been passed down through their own family.
Students will be able to understand the genetic background of genetic disorders.
Vocabulary: chromosome, karyotype, pedigree, autosomal, genetic disorder, heart disease,
Hemophilia, Cystic Fibrosis, Sickle Cell Anemia, Down Syndrome, trisomy, nondisjunction,
Diabetes, Heart Disease,
Essential Key Questions: How can you predict the traits that will be passed from generation to
generation?
Assessment: completion of Polygenic Pedigree Challenge
Materials/Resources: Polygenic Pedigree Challenge worksheets, pedigree worksheets, colored
pencils, assortment of colored pom-poms, guided notes sheets
Technological resources: PowerPoint, YouTube
Learning activities: PowerPoint note-taking, partner activity work
Initiation: Do It Now!
Lesson Procedures: Begin Human Genetics PowerPoint. Review the number of chromosomes in
human cells and the difference between autosomes and sex chromosomes. Introduce what a
karyotype is, what it looks like, and how to read one. Introduce what a pedigree is and all of the
different symbols. Explain how to label the symbols on guided notes.
Lou Gehrig’s Disease = Amyotrophic Lateral Sclerosis
 progressive neurodegenerative disease that affects the motor neurons and
signals being sent from the brain to the spinal cord and muscles
 Lou Gehrig and Stephen Hawking
Down Syndrome
 an extra chromosome 21 (3 chromosome 21—trisomy)
There are 3 patterns of inheritance that we can use to analyze pedigrees: Sex-Linked, Autosomal
Dominant, and Autosomal Recessive.
Sex-Linked: Genetic diseases that follow this pattern of inheritance are inherited on the
X-chromosome. If a genetic trait or disease is sex-linked, there will be more males affected by the
trait or disease than females.
 Color-blindness is a sex-linked genetic disease where people cannot
distinguish between the colors red and green. Some people could also be blueyellow color-blind.
 Hemophilia is a sex-linked genetic disease where people can have severe
difficulties with blood clotting. We bump ourselves all the time every day but
people with Hemophilia are at serious risk of internal bleeding when they
experience physical contact.
 Muscular Dystrophy: disorder of muscle degeneration
 Fragile X Syndrome:
 Turner Syndrome: only have 1 X chromosome; results in short stature and
sexual development issues.
 Klinefelter Syndrome: have 2 X and 1 Y chromosomes; have both male (small
sterile testes) and female (breasts) characteristics
Autosomal Recessive: Genetic diseases that follow this pattern of inheritance are on one
of the autosomal chromosomes. The easiest way to determine if a pedigree shows an autosomal
recessive trait is if the trait/disease skips a generation. The parents do not have to have the disease
or trait, but they could carry it (heterozygous) and pass on their recessive allele.
 Cystic Fibrosis: A genetic disease that is always showcased on CAPT. People
with CF have excess mucus in their lungs, digestive tract, and liver and they are
more susceptible to infections.
 Albinism: Albinos do not have any melanin in their skin, hair, or eyes. Melanin
is the pigment that gives our eyes, hair, and skin its color. Has anyone ever
seen an albino person and the color of their eyes? Red because of the blood
vessels.
 Galactosemia: accumulation of galactose in tissues which can lead to mental
retardation.
 Phenylketonuria (PKU): accumulation of the amino acid phenylalanine in
tissues can lead to mental retardation. What is an amino acid? Have you ever
noticed the phenylalanine warning on soda cans? People with PKU cannot
consume foods with phenylalanine or they will develop the disease. People can
be born with PKU and only develop the disease if they consume phenylalanine.
 Tay-Sach’s disease: lipid accumulation in the brain, infants typically don’t live
past a few years. Do you remember the stem cell video about the case study
of infants with Tay-Sach’s?
Autosomal Dominant: Genetic diseases that follow this pattern of inheritance are more
likely to be inherited from generation to generation because the heterozygous genotype and
homozygous dominant genotype is the disease. Only one of the parents has to have at least 1
dominant allele for the disease. One copy of the bad gene can cause the disorder.
 Marfan Syndrome: people have an overgrowth of bone and can have
abnormally long limbs or fingers.
 Achondroplasia: a type of dwarfism disease where the homozygous dominant
genotype is lethal and the heterozygous genotype makes those people have short
stature.
 Huntington’s disease: neurodegenerative disorder that affects muscle
coordination.
 Sickle Cell Anemia: red blood cells are sickle-shaped (crescent moon) and
therefore cannot carry oxygen as well. People with sickle cell are resistant to
malaria because the parasite in malaria doesn’t host on sickle-cell red blood
cells. This is why sickle-cell anemia is most common in blacks in Africa.
 Hypercholesterolemia: having high levels of cholesterol in the blood can lead
to heart disease. What is cholesterol? What type of organic molecule is
cholesterol? Cholesterol is a lipid that is needed in the cell membrane which
helps make it fluid, but too much can clog blood vessels and lead to heart
disease.
Polygenic Diseases: two very common diseases in the United States have some genetic
component, Diabetes and Heart Disease.
 Juvenile Diabetes (Type 1) is associated with risk factors that can be inherited
and certain environmental factors can trigger the disease later in life, such as
cold weather, viruses, and diet. Researchers are still unsure of specific
environmental triggers.
 Type 2 Diabetes (Adult Onset Diabetes) has a stronger genetic link but it also
depends on environmental factors such as lifestyle. Type 2 Diabetes is more
common in families where obesity is also common.
 Heart Disease is known to be polygenic because there are more than one gene
that has been researched to cause it. When someone has all of those genes, they
are at high risk of developing heart disease. When someone only has one or
two of those genes, they are at low risk for developing heart disease.
Let’s watch a short video about someone who developed heart disease.
https://www.youtube.com/watch?v=C_tHNMZF_Q0
Pass out Polygenic Pedigree Challenge worksheet. Each lab pair will get two cups each of colored
pom-poms. One cup is grandma’s genes, one cup is grandpa’s genes. First, color the circles on
the pedigree for grandma and grandpa based on what colors are in your cups. Then, randomly
select 3 pom-poms each from grandma and grandpa to determine the genes that will get passed on
for each child. Randomly select pom-poms for one child at a time and color them in on the
pedigree. You do not have to randomly select pom-poms the son’s partner, the directions tell you
what to color her circles. When you are finished with drawing pom-poms and coloring, go back
to your seat and work on the questions. Transition to lab benches to begin activity.
Closure: Discuss questions on Polygenic Pedigree Challenge. Exit ticket about pedigrees.
Intervention: Guided notes sheets for PowerPoint
Enrichment: Case Study pedigree of a genetic disease
Reflection: