Lesson Plan Presentation: What is our risk of developing a disease?
Key Words: Genetics, heredity, risk, diabetes, heart disease
Background: Cardiovascular disease (CVD) is the leading cause of diabetes-related
deaths. People with diabetes are much more likely to develop CVD due to a variety of
risk factors, including high blood pressure, lipid disorders, smoking, obesity and lack of
physical activity. Ethnically diverse populations such as Hispanics and Native Americans
have some of the highest prevalence rates of Diabetes and CVD. Type II Diabetes
Mellitus (T2DM) is the most common form of diabetes, where either the body does not
produce enough insulin or the cells ignore the insulin. Because it acts as the transporter
for the main "fuel" of the cell, glucose, insulin is necessary to the overall physiology of
the body. Over time, high blood glucose levels can cause harm to the kidneys, eyes,
nerves and heart.
Dyslipidemia, which is defined as the disruption in the amount of lipids in the
blood, can contribute significantly to CVD development in T2DM patients. Most
dyslipidemias are hyperlipidemias, which is an elevation of "bad" cholesterol, consisting
of low density lipoproteins (LDL) and triglycerides (TG). This also tends to cause a
decrease in the "good" cholesterol which are high density lipoproteins (HDL). Studies
have also shown that prolonged elevation of insulin levels can lead to dyslipidemia.
Goal: The goal of this lesson is to have students learn that common chronic diseases
(such as diabetes and CVD) run in families and are caused by the combined action of
multiple genes. Before the goal of this lesson can be accomplished I must first introduce
the concept that genes are passed from parents to offspring and contribute to our
phenotypes (physical characteristics).
Objectives:
-DNA is a set of instructions that specifies the traits of an organism.
-Information in the DNA molecule is divided into segments (called genes).
-Variations in the DNA lead to the inheritance of different trait.
-An inherited trait can be determined by one or by many genes.
-Many common diseases run in families and have a genetic component.
-Most common diseases are caused by the combined action of multiple genes and
environmental factors.
Standards:
ARIZONA STATE STANDARDS:
Comprehensive Health Standards (Grades 6-8)
STANDARD 1
Students comprehend concepts related to health promotion and disease prevention.
1CH-E1. Explain the relationship between positive health behaviors and health care
and the prevention of injury, illness, disease, disability and premature death.
PO 1. Illustrate how positive health behaviors can prevent common injuries, diseases and
conditions.
1CH-E3. Explain how health, growth and development are influenced by the
interaction of body systems, genetics, environment and lifestyle
PO 1. Develop a plan for a healthy environment and lifestyle and apply it to health,
growth and development
1CH-E5. Explain how environmental health and personal health are interrelated
PO 1. Compare healthy environments and healthy people with unhealthy environments
and unhealthy people
1CH-E6. Describe ways to reduce risks related to adolescent health problems
PO 1. Identify personal health behaviors that reduce health problems
PO 2. Illustrate the harmful effects of use of tobacco, alcohol and other drugs
1CH-E7. Describe how lifestyle and family history are related to the cause and
prevention of disease and other health problems
PO 1. Describe how living a healthy lifestyle and knowing family health history can help
a person live a more healthy life
Science Standards (Grade 6):
Strand 1: Inquiry Process
Concept 1: Observations, Questions, and Hypotheses
PO 1. Differentiate among a question, hypothesis, and prediction.
PO 2. Formulate questions based on observations that lead to the development of a
hypothesis.
Strand 3: Science in Personal and Social Perspectives
Concept 2: Science and Technology in Society
PO 1. Propose viable methods of responding to an identified need or problem.
PO 2. Compare possible solutions to best address an identified need or problem
PO 3. Design and construct a solution to an identified need or problem using simple
classroom materials
NATIONAL STANDARDS:
Grades 5-8:
Content Standard C: Life Science - Reproduction and Heredity
A new individual receives genetic information from its mother and its father.
Hereditary information is contained in genes. An inherited trait of an individual can be
determined by one or by many genes.
Some traits are inherited and others result from interactions with the environment.
Content Standard F: Science in Personal and Social Perspectives - Risks and Benefits
Risk analysis considers the type of hazard and estimates the number of people that might
be exposed and the number likely to suffer consequences. The results are used to
determine the options for reducing or eliminating risks.
Materials:
Colored pencils
Disposable cups
1 bag of jelly beans
Copies of pedigree sheets
Introduction of the lesson:
Begin by asking if they have noticed any similarities or differences among dogs
or any other type of animal family. Allow them to explore this question by asking them
to attempt to pair litter offspring with their adult dog parents using cut up pictures of
various dog litters. (Any animal that reproduces in litters can be used as a visual
representation). Activity one will hopefully lead into a discussion of heredity and the
introduction of the idea that variations in DNA strands lead to the inheritance of different
traits. This knowledge will allow them to come up with different hypotheses about why
offspring don’t always look like their parents. This concept can then be related to
humans.
Then ask the students if they think common human diseases like heart disease or
diabetes have a genetic component? If the students do not get to this point then bring up
the fact that many genetic disorders are usually not caused by defects in a single gene.
Instead, they result from the combined effects of multiple genes and environmental
factors. Then have the students generate a list of environmental factors that could
contribute to the development of diseases such as diabetes and heart disease. Finally ask
the students if they can come up with ideas about how we can “guess” or estimate an
individuals risk for developing these polygenic disorders. (Hopefully they will come up
with the concept of looking at family history).
Procedures:
1. Obtain a blank pedigree, colored pencils, 2 disposable cups, and an assortment of
colored jelly beans.
2. Choose one cup that will represent a mother. Place inside the cup 5 red jelly beans (5
“normal” genes that do NOT contribute to diabetes) and 1 blue jelly bean (1 gene that
increases diabetes risk).
3. Choose one cup that will represent a father. Place inside the cup 3 red jelly beans (3
“normal” genes that do NOT contribute to diabetes), as well as 1 orange, 1 green, and 1
yellow jelly bean (3 genes that increase diabetes risk).
4. On the pedigree, record the colors of jelly beans present in both the mother and father
by filling in the blank circles using colored pencils.
5. With closed eyes, mix and randomly draw out 3 jelly beans from each parent (6 jelly
beans total). This will represent the genetic information inherited by their first child.
6. On the Pedigree, color in the combination of jelly beans that were passed on to the
child.
7. Return the jelly beans to the appropriate parent. (Give mother’s genes back to mother,
and give father’s genes back to father.)
8. Repeat steps 5-7 for each son or daughter in the second row of the pedigree.
9. Diagnosis:
Look at each individual’s 6 heart disease susceptibility genes (their combination of
colored jelly beans). Label each individual in your pedigree as low, medium or high risk
according to the chart provided.
Assessment: After an informative discussion following the activity described above.
The students should be able to identity that environmental factors in addition to genetic
factors can influence an individual’s risk of developing multifactorial diseases.
Therefore, for the final assessment the students will be asked to design a promotional
campaign that will be geared toward educating the public about how to reduce their risk
of developing common diseases such as diabetes and heart disease.