Introduction to heredity curriculum final

Unit Overview
Five easy-to-implement classroom activities teach the basics of heritable
traits. Three take-home activities help students share what they're learning
with their families.
Learning Objectives
 Traits are observable characteristics
that are passed from parent to child.
 An individual will have many traits in
common with others and more so with
siblings and parents.
 An individual's overall combination of
traits makes them unique.
 Some traits are more common in a
population than others.
 An equal number of traits are passed
from each parent.
 DNA is a set of instructions that
specifies the traits of an organism.
Time Required
approx. 120 mins
Grade Band
Prior Knowledge Needed
Targeted Standards
CBSE: Life Science; Reproduction and
Heredity AAAS Benchmarks: The Living
Environment: Heredity
 Variations in DNA lead to the inheritance of different traits.
Suggested Implementation
8-10
None
Below is a suggested sequence for implementing the activities contained in
the unit. Please see each individual activity for implementation instructions,
suggestions for adaptations and extensions, and applicable standards.
UNIT CONTENT
Introduction to Heredity
Lesson Plans
An Inventory of My Traits
A Tree of Genetic Traits
Generations of Traits
Traits Bingo
A Recipe for Traits
Take-Home Activities
Family Traits Trivia
Handy Family Tree
Family Traits & Traditions
Teacher Resources
Inherited Traits:
A Quick Reference
Sample Parent Letter (doc)
Note About PTC Safety

DAY Activity Notes
Day 1
(40 mins.)
An Inventory of My Traits Students take an inventory of their own easily-observable
genetic traits and compare those
inventories with other students in groups.
Observable Traits
slideshow
(Teacher Reference)
This click-through slideshow shows many of
the traits included in An Inventory of My Traits.
A Tree of Genetic Traits Students find the most and least common
combination of traits in the class by marking
their traits for tongue rolling, earlobe
attachment, and PTC tasting on paper leaf cut-outs.
Students then organize the leaves on a
large "tree of traits."
(Homework)
Students use game cards to inventory the traits
in their family. (Note: individuals in families do
not need to be related to participate in this
activity.)
Day 2
(40 mins.)
Generations of Traits Students track and record the passage of
colored "pom-pom traits" through three
generations of ginger-bread people.
Traits Bingo In this review activity, students cross off or color
bingo squares in response to questions about
their traits.
Handy Family Tree
(Homework)
Students distinguish between inherited and
learned traits by creating a "family tree of traits"
using handprints. (Note: Individuals in families
do not need to be related to participate in this
activity.)
Day 3
(40 mins.)
A Recipe for Traits Students learn that differences in DNA lead to
different traits by: 1) randomly choosing strips
of paper that represent DNA, then 2) decoding
the DNA strips to complete a drawing of a dog.
Family Traits and
Traditions (Homework)
Students and their families play a matching
game with cards to identify traits that are
inherited and traits that are learned or passed
on through tradition.

A Recipe for Traits
Every organism inherits a unique
combination of traits.
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 traits.
Special Features
You’ll Find Inside
Copy masters for preparing
colored DNA strips having
fun symbols to represent
information about traits.
A dog traits key that allows
participants to decode their
DNA recipe and visualize how
traits are specified.
Activty Overview
Participants create and decode a “DNA recipe” for
man’s best friend to observe how variations in DNA
lead to the inheritance of different traits. Strips of
paper (representing DNA) are randomly selected
and used to assemble a DNA molecule. Participants
read the DNA recipe to create a drawing of their
pet, and compare it with others in the group to note
similarities and differences.
Logistics
Time Required
Activity Time:
40 minutes
Prep Time:
30 minutes to review activity, make copies,
and prepare dog DNA strips
Materials
Copies of participant pages, drawing paper, crayons
or colored pencils, tape, envelopes, and colored
paper (4 different colors needed)
Traits are heritable characteristics.
Learning Objectives
R.V.Raghavendra Rao, PGT Biology, Vizianagaram A.P. 2013 Heredity

Preparation
A Recipe for Traits
“Dog DNA” envelopes:
1. To prepare 14 envelopes, make four copies each of DNA Strips A, B,
C, and D (pages 4-7) on colored paper. Choose one color for each
type of DNA Strip. For example:
DNA Strips A (page 5) 4 copies on Blue
DNA Strips B (page 6) 4 copies on Green
DNA Strips C (page 7) 4 copies on Yellow
DNA Strips D (page 8) 4 copies on Red
Quantities
Per Participant or Pair
One copy of pages P-1 to P-3
One envelope containing
“Dog DNA” (see instructions
at left)
Crayons or colored pencils,
drawing paper, tape
2. Cut out the DNA strips on each page (a paper-cutter works well).
3. Place two DNA strips of each color into an envelope. The envelope should contain eight DNA strips total
(four different colors).
4. Repeat step three until you have assembled 14 “Dog DNA” envelopes.
Note: Eight is the minimum number of DNA strips per envelope that you need to carry out the activity. Adding
more DNA strips of each color increases the variety of possibilities for each trait.
Activity Instructions
• Display different types of instructions (e.g. a recipe book, a blueprint, a DNA molecule). Ask participants
what they might use these instructions for. Explain that just as a recipe is used to cook a meal or a blueprint
is used to build a home, DNA contains instructions that specify an organism’s traits.
• Read the beginning paragraph of A Recipe for Traits (page P-1) as a group. You may want to show a
completed DNA “recipe” and point out the different segments (representing genes) as well as the 4 symbols
(representing the 4 chemical bases A, C, G and T) that make up the DNA alphabet in this activity.
• Review the instructions on page P-1. You may want to demonstrate how to use the Dog Traits Key (see page
P-2 to P-3). Read the DNA recipe and identify the first trait.
• Remind participants to leave the DNA strips they choose out of the envelope and tape them together in
order. The resulting long strand will be their DNA recipe.
• Have participants work individually or in pairs to complete the activity. When participants have finished, have
them post their dog drawings on the wall along with the DNA recipe for their dog.
• Are any two dogs alike? Point out that every dog shares some traits in common with others, but each has an
overall combination of traits that is unique.
• Explain that variations in each DNA strand (the sequence of symbols) led to the inheritance of different traits.
2013 Heredity R.V.Raghavendra Rao, PGT Biology, Vizianagaram A.P. 1

Discussion Points
A Recipe for Traits
• Information in a DNA strand (or molecule) is grouped into small segments called genes (represented here by
colored DNA strips).
• A single DNA strand is often referred to as a chromosome. In this example, the dog had one chromosome
containing 8 genes. (Humans have 23 pairs of chromosomes containing over 22,000 genes!)
• The DNA molecule contains a sequence of four chemical bases (represented here by four symbols). Each
base is referred to by the first letter of its name: Adenine (A), Cytosine (C), Guanine (G) and Thymine (T). The
sequence of these chemical bases encodes a detailed set of instructions for building an organism’s traits.
(The human genome contains approximately 3 billion pairs or bases!)
• Participants were asked to assemble their DNA strips in the order they were drawn. This is because all
individuals of a species have the same genes in the same order along their chromosomes. (This is what
allows researchers to “map” the location of a gene to a specific place on a chromosome.) It is the small
sequence variations within each gene that lead to differences in traits.
• There is usually a limited number of sequence variations for a gene. That is, a gene usually comes in a few
different forms or flavors (called “alleles”). There was a possibility of four different flavors or alleles for each
of the dog genes in this activity.
• In this activity, a single gene determined each dog trait. More often a trait is influenced by more than one
gene as well as environmental factors.
Extension
• As a group, make a “map” of the dog genome. Compare the different DNA recipes hanging up in the room.
Point out that the gene for body shape is always at the top of the DNA molecule (or chromosome), the gene
for head shape is always second, and so on. Draw a representation of a chromosome having 8 segments.
Have participants come up with a creative name for each gene. Label the segments with the gene names,
and specify the trait they encode. Point out that although each dog looks differently (has a different
combination of traits), it is still possible to make a general map of the dog genome.
• Show participants a completed map of the human genome (e.g., the Human Genome Landmarks Poster
or its web companion) and discuss how researchers have mapped the 22,000 plus genes to particular
locations on the 23 pairs of human chromosomes. To order a free copy of this poster or view it online,
check out the web site developed by the U.S. Department of Energy’s Human Genome Management
Information System (HGMIS).
R.V.Raghavendra Rao, PGT Biology, Vizianagaram A.P. 2 2013 Heredity

DNA Strips A
A Recipe for Traits

DNA Strips B
A Recipe for Traits

DNA Strips C
A Recipe for Traits

DNA Strips D
A Recipe for Traits

A Recipe for Traits
A set of instructions called DNA makes a “recipe” for traits in all
organisms. Information in a DNA strand is grouped into small segments.
Each segment is made of even smaller units (like recipes are made of
words, and words are made of letters). Differences in the DNA “alphabet”
are what make differences in traits (just like a different sequence of
letters makes different words, and a different recipe).
Follow the directions below to create a DNA recipe for a dog. Using the Dog
Traits Key, read your DNA recipe and make a drawing of your dog showing all of
its traits.
Directions:
1. Make sure you have an envelope containing “Dog DNA”.
2. Determine the first trait of your dog (body shape) by randomly picking a
piece of dog DNA out of the envelope.
3. Look at the symbols on the DNA strip you have chosen. Match the pattern to
one you see on the Dog Traits Key for body shape.
4. Circle the picture for body shape that matches the DNA piece that you
picked.
5. Set the piece of DNA aside and repeat steps 1-4 for the next trait on the key.
6. After circling the matching picture, tape the second piece of DNA to the first
to make one long strand. This will become the DNA recipe for your entire
dog.
7. Repeat these steps for each of the traits listed on the Dog Traits Key.
8. When you have finished, draw your dog with all of its traits (the traits you
have circled on the Dog Traits Key) on a separate piece of paper.
9. Hang up the picture of your dog along with its DNA recipe (the DNA pieces
you chose attached in a long strand).
Is your dog different from or the same as others in the group?

Body Shape
Head Shape
Ears
Legs
Dog Traits Key
Small, Thin,
Long, Straight
Large, Thin,
Long, Tapered
Meduium, Very
Muscular, Short
Large Semi-
Muscular, Straight
Long, Thin Flat Short Droopy
Small, Pointy Big Droopy Medium Square Medium Droopy
Long, Thin Short, Stubby Medium Stocky, Muscular

Eyes
Dark Brown Light Brown Blue Green
Tail
Coat Color
Hair
Short Nub Long with
Short Hair
Pompon Tipped Long and Bushy
Brown Black Red-Brown Yellow
Curly, Short Straight, Short Straight, Long Wavy, Long
Dog Traits Key

Activity Overview Learning Objectives
Traits are observable
characteristics that are passed
down from parent to child.
An individual will have many
traits they share in common
with others.
An individual’s overall
combination of traits makes
them unique.
Some traits are more common
in a population than others.
Participants mark their traits for tongue rolling,
PTC tasting (a harmless, bitter chemical), and
earlobe attachment on tree leaf cut-outs. They
then place their leaves on a large tree whose
branches each represent a different combination
of traits. When completed, the tree forms a
visual representation of the frequency of trait
combinations within the group.
Logistics
Time Required
Activity Time:
30 minutes
Prep Time:
30 minutes to review activity, make copies
of tree leaf cut-outs, and prepare traits tree
Materials
PTC paper, hard candies, leaf cut-outs, tape,
scissors, transparencies or large butcher paper
None
R.V.Raghavendra Rao
Department of Biology

R.V.Raghavendra Rao
Quantities
Per Participant
One leaf cut-out, hard candy,
piece of PTC paper
1
Per Group of 2
• Copy the Genetic Traits Tree graphic provided on page 4 (or
page 6 for Telugu speaking audiences) onto an overhead
transparency. Use an overhead projector to project the
transparency large onto a blank wall. Alternatively, draw a large tree
on butcher paper based on page 4. Post it in an easily accessible
and visible area of the room.
• Provide each participant with a leaf and instruct them to cut it out.
Scissors, pen or pencil
• Explain that traits are observable characteristics we inherit from our
Whole Group
parents. Demonstrate the tongue rolling and earlobe attachment
traits. Have participants mark “yes” or “no” on their leaf for these
Tape
traits as appropriate.
• Hand out PTC paper. Instruct participants to place a piece of PTC paper on the tip of their tongue to see
if they can taste anything. The chemical tastes bitter to those who can taste it. For those who cannot
taste PTC, the paper has no taste.
• Note: PTC paper is inexpensive and can be purchased from Sargent Welch (www.sargentwelch.
com), Carolina Math and Science (www.carolina.com) or Ward’s Natural Science (http://www.
wardsci.com).
• Instruct participants to check “yes” or “no” on their leaves for PTC tasting. Hand out a hard candy to each
participant to neutralize the taste of the PTC.
• Demonstrate how to determine where to place the leaves on the Trait Tree starting at the base of the
branches and working your way out toward the tips.
Common • Call participants up in groups to place their leaves on
Misconception
the appropriate branches. The leaves will be clustered
A widespread misconception is that all traits
around the branch representing the most common
exhibit either a dominant or recessive pattern of
combination of traits in the group. Some branches of
inheritance. But these terms only apply to single
the tree will remain relatively sparse.
gene traits. The traits included in this activity are
part of the small number that may be due to only
• Optional: Make leaf cut-outs in two different colors,
one or two genes. However, most human genetic
one for males and one for females, to track
traits are influenced by several genes as well as
combinations of traits within the different genders.
interactions with the environment. The inheritance
of complex traits is difficult to predict, and does
• Optional: Increase your data pool by including
not follow typical dominant or recessive patterns.
additional groups in the exercise, taping all leaves to
one tree.

R.V.Raghavendra Rao
2
Discussion Points
• Some traits are more common in a population than others. What is the most common combination of traits
in the group? What is the least common combination of traits in the group?
• Every person has a unique combination of traits. If we were to look at more traits than three, we would
eventually need a branch on the Trait Tree for each person in the group.

R.V.Raghavendra Rao
3
LAenaf I nCvuetn-toourtys of My Traits: Leaf Cut-Outs
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No
Earlobes
Attached Free
PTC Tasting
Yes No
Tongue Rolling
Yes No

4
Example Trait Tree
Non-PTC
Taster
PTC
Taster
PTC
Taster Non-PTC
Tongue Taster
Roller
Attached
Earlobes Free
Earlobes
Tongue
Roller
Tongue
Roller
Tongue
Roller
Non-Tongue
Roller
Non-Tongue
Roller
Non-Tongue
Roller
Non-Tongue
Roller

Materials needed
• One large piece of paper or poster
board
• Colored paper (one or two for each
person)
• Scissors
• Pens or markers
• Tape or glue
Instructions
R.V.Raghavendra Rao
Inherited traits are physical characteristics that can be
passed down from parent to child. Learned traits are
acquired through interactions with the environment. This
activity can help you learn to distinguish between inherited
and learned traits.
1 2
1
Handy Family Tree
Trace the right and left hand of each family
member onto a piece of colored paper
Cut out the handprints
A family tree is a picture that shows members
of your family. It can include information about
each person. Do this activity to create your own
family tree. Include fun facts about each family
member on their very own handprint!
Did You Know?

Trait no one else in your family has
Trait shared with a brother or sister
Trait shared with a parent
Trait shared with a grandparent
On each finger of your left handprint list a trait (physical
characteristic) that you have inherited such as:
• eye color
• hair color
• dimples
• freckles
• chin shape (smooth or cleft)
• ability to roll the tongue
• earlobe attachment (attached or free)
• hairline shape on the forehead (smooth or pointed)
R.V.Raghavendra Rao
On each finger of your right handprint, list a trait
that you have acquired or learned.
See suggestions above.
Glue or tape your family’s handprints above the trunk to form a tree.
Place the oldest person’s pair of hands at the bottom. Work upward
until you place the youngest person’s pair of hands at the top.
Optional
Word describing your character
Favorite game, sport or hobby
Favorite food
Favorite school subject
3
4
5
2
Draw a tree trunk onto a large piece of paper or poster board.
• Add a small picture of each family member to the palm of one handprint.
Write their name, date of birth, and place of birth on the palm of the
other handprint.
• Include handprint shapes for family members who were not available
to draw their hands. See how your parents’ or grandparents’ favorites
compare to yours!

R.V.Raghavendra Rao
Inherited Human Traits: A Quick Reference
Special Features
Photos of common heritable
traits and accompanying
background information.
Activity Overview
Background information about genes, traits and
inheritance that supports the activities included in
the Heredity & Traits section of the Learn.Genetics
website. Includes a pictorial reference of inherited
human traits, along with inheritance patterns,
frequencies and other interesting facts about each.
1

R.V.Raghavendra Rao
Background Information
Physical traits are observable characteristics determined by specific segments of DNA called genes. Multiple
genes are grouped together to form chromosomes, which reside in the nucleus of the cell. Every cell (except
eggs and sperm) in an individual’s body contains two copies of each gene. This is due to the fact that both
mother and father contribute a copy at the time of conception. This original genetic material is copied each time
a cell divides so that all cells contain the same DNA. Genes store the information needed for the cell to assemble
proteins, which eventually yield specific physical traits.
Figure 1: Inheritance Patterns of the Widow's Peak Trait
Most genes have two or more variations, called alleles. For example,
the gene for hairline shape has two alleles – widow’s peak or straight.
W = dominant widow's peak allelle
w = recessive straight hairline allele
An individual may inherit two identical or two different alleles from
their parents. When two different alleles are present they interact
Results of Allele Combinations:
in specific ways. For the traits included in this activity, the alleles
interact in what is called a dominant or a recessive manner. The
WW =
Widow's Peak Trait
traits due to dominant alleles are always observed, even when a
recessive allele is present. Traits due to recessive alleles are only
observed when two recessive alleles are present. For example, the
Ww =
allele for widow’s peak is dominant and the allele for straight hairline
Widow's Peak Trait
is recessive.
If an individual inherits:
ww =
Straight Hairline Trait
• Two widow’s peak alleles (both dominant), their hairline will have a
peak
• One widow’s peak allele (dominant) and one straight hairline allele (recessive), they will have a widow’s peak
• Two straight hairline alleles (recessive), their hairline will be straight.
A widespread misconception is that traits due to dominant alleles are the most common in the population.
While this is sometimes true, it is not always the case. For example, the allele for Huntington’s Disease is
dominant, while the allele for not developing this disorder is recessive. At most, only 1 in 20,000 people will get
Huntington’s; most people have two recessive, normal alleles.
While a few traits are due to only one gene (and its alleles), most genetic traits are the product of interactions
between several genes. When more than one gene influences a trait, the inheritance pattern is not easily
predictable. The predictable patterns referred to as dominant and recessive apply only to single gene traits.
The traits listed on the next pages have commonly been presented as being determined by single genes.
However, it is possible that some may involve more than one gene. When research studies have disagreed on
the inheritance pattern for a trait, it has been noted below.
1

R.V.Raghavendra Rao
Earlobe Attachment
Attached Earlobes Detached Earlobes
If earlobes hang free, they are detached. If they attach directly to
the side of the head, they are attached earlobes.
Some scientists have reported that this trait is due to a single
gene for which unattached earlobes is dominant and attached
earlobes is recessive. Other scientists have reported that this
trait is probably due to several genes.
The size and appearance of the lobes are also inherited traits.
Tongue Rolling
In 1940, the famous geneticist Alfred Sturtevant noted that
about 70% of people of European ancestry are able to roll up
the lateral edges of the tongue, while the remaining 30% were
unable to do so.
Tongue rolling ability may be due to a single gene with the
ability to roll the tongue a dominant trait and the lack of
tongue rolling ability a recessive trait. However, there is some
question about the inheritance of tongue rolling. Recent studies have shown that around 30% of identical
twins do not share the trait.
Cleft Chin
This trait is reportedly due to a single gene with a cleft chin dominant and a smooth chin recessive.
Dimples
Dimples are reportedly due to a single gene with dimples dominant (people
may exhibit a dimple on only one side of the face) and a lack of dimples
recessive.
Handedness
Some scientists have reported that handedness is due to a single gene with right handedness dominant and left
handedness recessive. However, other scientists have reported that the interaction of two genes is responsible
for this trait.
2
Can Roll Tongue Can’t Roll Tongue

R.V.Raghavendra Rao
Freckles
This trait is reportedly due to a single gene; the presence of freckles is dominant, the absence of freckles
is recessive1.
Naturally Curly Hair
Early geneticists reported that curly hair was dominant and straight hair was recessive. More recent studies
suggest that more than one gene may be involved.
Allergies
While allergic reactions are induced by things a person comes in contact with, such as dust, particular
foods, and pollen, the tendency to have allergies is inherited. If a parent has allergies, there is a one in
four (25%) chance that their child will also have allergy problems. This risk increases if both parents have
allergies2.
Hand Clasping
Fold your hands together by interlocking your
fingers without thinking about it. Which thumb
is on top – your left or your right?
One study found that 55% of people place
their left thumb on top, 45% place their right
thumb on top and 1% have no preference.
A study of identical twins concluded that
hand clasping has at least some genetic
component. However, other scientists have
not found evidence that genetics plays a
significant role in determining this trait.
Colorblindness
Colorblindness is due to a recessive allele located on the X chromosome. Women have two X
chromosomes, one of which usually carries the allele for normal color vision. Therefore, few women are
colorblind. Men only have one X chromosome, so if they carry the allele for colorblindness, they will exhibit
this trait. Thus, colorblindness is seen more frequently in men than in women.
3
Cross Left Thumb Over Right Cross Right Thumb Over Left

R.V.Raghavendra Rao
Hairline shape is reportedly due to a single gene
with a widow’s peak dominant and a straight hairline
recessive.
Hairline Shape
Widow’s Peak Hairline Straight Hairline
PTC Tasting
For some people the chemical PTC (phenylthiocarbamide)
tastes very bitter. For others, it is tasteless.
The ability to taste PTC shows dominant inheritance and is
controlled by a gene on chromosomes 7. This gene codes for
part of the bitter taste receptor in tongue cells. One of its five
alleles (forms) causes a lack of ability to sense bitter tastes;
the other four alleles produce intermediate to fully sensitive
taste abilities. Approximately 75% of people can taste PTC
while the remaining 25% cannot.
PTC-like chemicals are found in the Brassica family of vegetables, such as cabbage, brussels sprouts,
and broccoli. People who can taste PTC often do not enjoy eating these vegetables, since they taste
bitter to them. Non-tasters tend not to notice bitter tastes and therefore may be more likely to become
addicted to nicotine (which is bitter).
PTC-tasting ability has also provided information related to human evolution. Populations in Sub-Sahara
Africa, and people who are descended from this area, contain at least five forms of the gene. Some of
these forms confer a PTC-tasting ability that is intermediate between taster and non-taster. However,
with only a few exceptions, only two forms – taster and non-taster – are found in populations outside
of Africa and their descendents. This is consistent with the out-of-Africa hypothesis of modern human
origins.
Some scientists think that tasters have fewer cavities, suggesting that there might be a substance in
the saliva of tasters that inhibits the bacteria that cause cavities to form. Others think that PTC tasting
may be in some way connected with thyroid function.
PTC tasting was a chance discovery in 1931.
4
Does Not Taste PTC Tastes PTC

R.V.Raghavendra Rao
Pick the Risk: The Polygenic Pedigree Challenge
Activity Overview
Participants are challenged to track and record the
passage of colored pom poms (representing genes)
through generations of a family using a pedigree.
Participants learn that common chronic diseases
(such as heart disease) run in families and are
caused by the combined action of multiple genes.
Activity Time:
Prep Time:
30 - 45 minutes 30 minutes
Logistics
Time Required
Materials
Copies of participant pages, colored pencils or
crayons, disposable cups, colored pom poms
Genes are passed from parents to offspring
and contribute to observable physical
characteristics. Pedigrees are used to track
genetic information.
Learning Objectives
An inherited trait can be determined
by one or by many genes.
All humans have the same genes,
but each inherits slightly different
forms or “flavors” of each gene.
Many common diseases (such as
heart disease) run in families and
have a genetic component.
Most common diseases are caused
by the combined action of multiple
genes and environmental factors.
An individual’s risk of developing
a common disease is estimated
by looking at siblings, parents and
grandparents in a family medical
history.

Quantities
Per Group of 2
To engage participants in this topic:
• Compare the prevalence of rare genetic disorders caused by a single
gene such as cystic fibrosis (1 in 10,000) with the prevalence of more
common diseases such as heart disease (1 in 3).
• Ask the participants: Do common diseases like heart disease, diabetes,
or colon cancer have a genetic component?
• Explain that most common diseases do have a genetic component and
tend to run in families. However, common diseases differ from rare
genetic disorders in that they are usually not caused by defects in a
single gene. Rather, they result from the combined effects of multiple
genes and environmental factors. Thus, they are called multifactorial diseases.
• Explain that because more than one gene is involved in most common diseases, the inheritance of a
common disease is not predictable.
• Information found in a family health history and recorded on a pedigree is used to estimate an individual’s
genetic risk (low, medium, or high) of developing a common disease.
Begin activity:
• Explain that the following activity will explore how common “polygenic” diseases (in this case, heart disease)
are inherited.
• Invite participants to find a partner with whom they will work to complete the activity; pass out the participant
pages and other materials.
• Review the symbols and structure used for a pedigree:
1
Instructions
One copy of participant
pages
2 - 3 disposable cups
Colored pencils or crayons
Colored pom poms (5
different colors: at least
10 red, 2 yellow, 1 each of
orange, green, blue)
Generation I
Grandmother
Grandfather
Children listed in birth order
This line connects parents
and their children.
= Female
= Male
This line connects a
male/female couple.
Oldest Youngest
Grandchildren
Generation II
Generation III
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R.V.Raghavendra Rao
Common Misconception
Participants may think that all heritable traits
(and genetic disorders) are caused by a single
gene and exhibit dominant or recessive patterns
of inheritance. But more commonly, traits result
from the combined action of many genes and
environmental factors. Such multifactorial traits
can exhibit varied and complex patterns of
inheritance that are not easy to predict.
2
• Invite participants to begin by following the instructions
found on pages P-1 and P-2; each pair of participants should
complete the pedigree analysis and answer the questions that
follow.
Group discussion:
• Point out that this activity differs from reality in the following
ways:
»» The number of genes contributing to a polygenic disease is
usually not known.
»» The number of genes carried by parents or offspring that
can increase heart disease risk is not known.
»» Environmental factors can also vary an individual’s risk of developing multifactorial diseases.
• Discuss the following questions as a group, comparing and contrasting the Pedigree results obtained by
each pair:
»» The grandfather in this family was a “high risk” individual. How many of his children were either medium
or high risk individuals? How many of his grandchildren were either medium or high risk individuals?
(Answers will vary.)
»» Did the number of “medium risk” and “high risk” individuals decrease or increase over subsequent
generations? Why do you think that happened? (Answer: Decrease. Risk of inheriting heart disease
from an affected individual (suchas a grandparent) decreases through the generations because it is
unlikely that all of the necessary risk factors [genes] will be passed down to less closely related family
members.)
»» In this activity you were able to label family members as having a low, medium or high risk of developing
heart disease. In reality, do you think it might be difficult to predict an individual’s risk of developing heart
disease? Why? (Answer: An individual’s risk of developing heart disease IS difficult to predict because of
the reasons outlined under the first group discussion point.)
»» If a parent is diagnosed with heart disease, does that mean the children will have it also? Defend your
answer. (Be sure to include the key word “risk” in your answer.) (Answer: Not necessarily. But because
heart disease does have a genetic component, children of an affected parent have an increased risk of
developing heart disease relative to the population at large.)
• Emphasize that these are a few of the reasons why heart disease and other common diseases are so
complex, and why the inheritance pattern for such diseases are difficult to predict.
• Therefore, individuals are placed in general categories (high, medium, or low risk groups) based on features
from their family health history that correlate with a certain probability of developing a disease.
»» For example, it is said that an individual who has a parent (or possibly a grandparent) with heart disease
may be “at risk” and should take steps to protect themselves.
• Describe the important features to identify in a family health history (see chart at http://learn.genetics.utah.
edu/units/health), including what is meant by a “close” relative.

R.V.Raghavendra Rao
3
»» Siblings, parents, and possibly grandparents, are
informative when assessing an individual’s risk of
developing a common disease and need be included
in a family health history. It is unlikely that all of the
same risk factors (genes) will be present in less
closely related family members.
Learn More
Visit the elearning bio website to get
more great resources like this one!
• Discuss why each feature in the chart indicates an individual may be at increased risk for developing
heart disease.
»» Each feature indicates that the family has accumulated more risk factors (genetic or environmental).
Therefore, an individual in this family is more likely to develop disease.
• Discuss behaviors and choices that can reduce an individual’s risk of developing heart disease.
• Conclude the discussion by reminding participants that genetic susceptibility does not mean an individual will
inevitably inherit a disease. Positive lifestyle changes and healthy living can reduce genetic risk dramatically.
That is why it is so important to know your family health history. If you know you are “at risk” you can take
steps to protect yourself.

Risk Continuum
Activity Overview Learning Objectives
People can be assigned to a
risk group for developing heart
and other diseases based on
family history/genetics.
Lifestyle choices can positively
or negatively influence the risk
of developing heart disease.
A higher risk means a greater
chance of developing heart
disease, not an inevitability of
developing it.
Though a lower risk means
there is a reduced chance, it is
still possible for members of
this risk group to develop heart
disease.
Special Features
Diagrams to help set up the
demonstration.
A group kinesthetic demonstration of what it means
to be in a “risk group” for developing heart disease
based on family history/genetics.
Logistics
Time Required
Activity Time:
15 minutes
Prep Time:
10 minutes
Materials
Paper
None
R.V.Raghavendra Rao

R.V.Raghavendra Rao
Risk Continuum
Participant Action
1. Starting with the participant most at risk (left)
have each person choose a Lifestyle Choice
card without looking.
1
1
1
2
3
10 copies of Lifestyle Choice
Cards, cut to form individual
cards, (30 total). Shuffle
them and place them in a bag
or other container.
Leader Action
1. Line your participants up standing in a single row, shoulder to
shoulder, and facing the same direction.
2. Mark off two spots so that the line of participants are roughly
divided into thirds.
3. Explain that the participants now represent a continuum
ranging from those at the left who are genetically most at risk
for developing heart disease, and those at the right who are
least at risk. The “thirds” represent the broader categories of
high, medium and low risk groups.
4. Explain that each risk group correlates with a certain
probability of developing heart disease based on family history.
Lifestyle choices involving diet, exercise and smoking can
influence this risk.
Quantities
Per Group of 30

Risk Continuum
2
3
4
5
6
7
8
9
1 space
2 spaces
Participant Action (cont.) 2
2. Adjust the continuum to reflect lifestyle
choices:
A. Complete the following calculation:
Total # of participants = # of spaces to move
6
B. Ask the first participant to read his or her
Lifestyle Choice card and move the designated
number of spaces (calculated above) in the
following manner:
Healthy = move the # spaces to the right
Neutral = remain where you are
Negative = move the # spaces to the left
3. Have each participant repeat the above
process until all persons are arranged into the
newly formed continuum.
4. Have the participants reform into the divisions
outlined in leader action steps 1-3 and note
how their risk has changed after factoring in
lifestyle choices.
5. Within each of the thirds, the participants will
count off 1 to 4.
6. In the “high-risk” group on the left, those who
counted a 1 will be asked to sit down.
7. In the “medium-risk” group, those who counted
a 1 or 2 will be asked to sit down.
8. In the “low-risk” group on the right, those who
counted a 1, 2, or 3 will be asked to sit down.
9. Those standing represent the people that
developed heart disease.
R.V.Raghavendra Rao

R.V.Raghavendra Rao
Risk Continuum
Discussion Points
• People in all risk groups develop heart disease with the largest percentage being from the “high” risk group.
• Not all people in the high risk group develop heart disease.
• Making positive or neutral lifestyle choices can influence your risk enough to prevent developing heart disease.
(Ask participants for which this was true to raise their hands).
• Sometimes, people who make positive or neutral lifestyle choices still develop heart disease (Ask participants for
which this was true to raise their hands).
• Some people who make negative lifestyle choices do not develop heart disease, even though their risk is
increased.
3

R.V.Raghavendra Rao
Did You Know?
Inherited traits are physical
characteristics that can be passed
Hint
Cards with matching pictures have
different phrases. One card in
the pair describes a trait, and the
other card in the pair describes a
tradition.
1
Traits and Traditions: A Make-a-Match Game
Traits can be inherited from a parent, or traits can be learned.
Family and cultural traditions often influence learned traits.
Can you think of a trait you have inherited? How about a
trait that you have acquired by learning or tradition? Play this
game to discover some common traits and traditions!
Preparation
Object of the game
• Cut out the game cards. You may want to glue or tape the pages to heavy paper first.
• Use your memory to find the cards with matching pictures. The person to collect the most matches wins!
Instructions
1. Place the game cards face down and spread them out. Decide which player will go first.
2. The first player turns over two cards, looking for a match. All players should have a chance to see the
pictures on the two cards.
3. Read each card. Decide whether it describes an inherited trait (something you are born with) or a tradition
(something you learn). Record your answer by checking the box next to “trait” or “tradition”.
4. If the pictures on the cards MATCH, the player keeps the cards and
takes another turn. If the pictures on the cards DO NOT MATCH, the
player does not keep the cards. The cards are again turned face
down.
5. The next player turns over two more cards, looking for a match.
Continue to label each card as either a trait or a tradition.
6. Play until all the matches have been found. The person to collect the
most matches wins!
This project is supported by grant U33MC00157 from the Health Resources and Services Administration, Maternal and Child Health
Bureau, Genetic Services Branch and the March of Dimes.
To learn about our permissions policy, visit http://learn.genetics.utah.edu/permissions/

R.V.Raghavendra Rao
2
I have
attached
earlobes
Trait □ Tradition □
I have
pierced ears
I can roll my
tongue
I like to eat
spicy foods
Trait □ Tradition □ Trait □ Tradition □
I have
dimples
I greet
others with
a smile
My natural
hair color is
brown
I use dye to
change my
hair color

R.V.Raghavendra Rao
3
I am left-handed
I use my
hand to
catch a ball
I am color-blind
I like to
create art
I have
allergies
I care for
a pet
I have
freckles
I lay in the
sun to get
a tan

Traits Trivia
Every person is unique, yet we all have traits we share in common
with others. Families share many traits in common because
they are related. But unrelated individuals will also have traits in
common.
Traits Trivia includes two activities that can be done with any family
or group of individuals. Using the Traits Trivia game cards, you’ll
identify traits you have inherited and traits you share in common
with others. Then, try to be the last one standing as you discover
a combination of traits that is unique to you!
Preparation
Instructions
R.V.Raghavendra Rao
• Cut out the game cards. You may wish to glue or tape them on heavy paper first.
• Invite your group to sit in a circle. Hold up one game card at a time to show a picture of an inherited trait.
All who have this trait should stand or raise their hand. Continue with each game card to find similarities and
differences among individuals in your group.
»» Did you share a trait with another group member? An unrelated individual?
»» Did you find a trait that was unique to you?
»» Did each person in your group have a different combination of the traits described?
Once the group is familiar with all of the inherited traits described, try this second activity!
• Shuffle the game cards, then draw a card from the top of the deck. Invite your group to stand up and form a
circle. Show everyone the picture of the trait.
• Everyone who has this trait should stay standing. Those who do not have the trait should sit down. Once a
person sits down, they should not get up again. Continue with each game card until only one person is left
standing.
»» How many cards did it take to find one person with a unique combination of traits?
• Shuffle the cards and play again as many times as you would like.
Did You Know?
Inherited traits are physical
characteristics that can be
passed down from parent to child.
Learned traits are acquired through
interactions with the environment.

Attached earlobes Can roll tongue Dimples Right-handed
Freckles Naturally curly hair Cleft chin Allergies
Cross left thumb
over right
Can see red &
green
R.V.Raghavendra Rao

R.V.Raghavendra Rao
What’s Your Family Health Story?
How to Gather Family Health Information
Recording family health information and sharing it with your
doctor is an important first step to improving your health,
regardless of your family structure.
Tracking diseases that run in your family will help your doctor better predict what you need
to do to stay healthy.
The next time you’re at a family gathering, make
sharing your family health stories a tradition. It may
save your life and the lives of those you love!
Getting Started
Explain to your relatives that you are interested
in the family’s health story. Collect some basic
health information about your family members
using the Health Family Tree Information Boxes.
Let them know that any information they
provide will help you and your entire family
improve their health.
“The knowledge a person has
of their family’s health history
could be life saving, if that person
chooses to heed the possibilities”
- Judy
Common Health Problems that Run in Families
• Heart disease
• Cancer
• Stroke
• Diabetes
• Asthma
• Osteoporosis
• High blood pressure
• High cholesterol
• Depression
“ The only thing you have
control over in your family
health history is to empower
yourself enough to be aware
of what you’re potentially at
risk of so you can recognize
the symptoms or prevent
the disease from occuring.”
- Arianna
Corin Royal Drummond

R.V.Raghavendra Rao
How to Interview Your Family
The health stories of your siblings, parents and
grandparents will be the most useful to your
doctor. You may also want to gather information
about your aunts and uncles, half-brothers or
half-sisters (if any) and cousins.
Follow-up Questions
If a relative has experienced a health problem, ask follow-up questions that will help you learn more.
Find out how old they were when the health problem started, and ask about any lifestyle factors that
may have contributed to the problem (diet, exercise, overweight, smoking, etc.).
Living relatives can also provide important health
information about family members who are
deceased. Find out how old a family member
was when they died and ask about the cause of
death.
Remember to be respectful of others’ wishes.
Some family members may be reluctant to share
their health information with you. Just ask them
to share what they can.
Important to Find Out
• A description of any health problems
• The age at diagnosis (when the condition started)
• Allergies to foods or medications
• Lifestyle and health habits
• If deceased, the age and cause of death
Additional Resources
Visit the following websites to obtain more information about
family health history, including additional tools your family can
use!
Learn.Genetics (http://learn.
genetics.utah.edu) Using
Family History to Improve Your Health
contains information about
common diseases that run in
families, and what it means to
be “at risk”.
“I try to be a good example and
share what I know about our
family health history so future
generations won’t have to worry
about repeating the same fate.”
- Marian
The Utah Department of Health (http://health.utah.gov/
genomics/familyhistory/toolkit.html) Family Health History
Toolkit contains materials for your family, plus links to more
information about the importance of knowing your family’s
health history.
“I was surprised to learn what I did about
my health family history. It wasn’t until I
put it into a pedigree, or family tree, that I
began to see the pattern of depression that
ran from generation to generation.”- Jenny
Who Do I Need to Interview in my Family?
Also Important
• Aunts and Uncles
• Half-Brothers and Half-Sisters
• Cousins
Most Important
• Parents
• Brothers and Sisters
• Grandparents
Maya Jones

Health Family Tree Information Boxes
Family member first name:
Relationship:
Date of birth:
Health problems (check all that apply):
❑ Heart Disease
❑ Cancer
❑ Stroke
❑ Diabetes
❑ Asthma
❑ Osteoporosis
❑ High Blood Pressure
❑ High Cholesterol
❑ Depression/Mental Health
❑ Other ____________
Age of onset:
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
Does this family member smoke?
❑ Yes ❑ No
If yes,
Cigarettes smoked per day:
Number of years smoking:
Is this family member deceased?
❑ Yes ❑ No
If yes,
Age at death:
Cause of death:
Health-related lifestyle or environmental
factors for this family member:
Relationship:
Date of birth:
❑ Heart Disease
❑ Cancer
❑ Stroke
❑ Diabetes
❑ Asthma
❑ Osteoporosis
❑ Other ____________
Age of onset:
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
❑ Yes ❑ No
If yes,
❑ Yes ❑ No
If yes,
Age at death:
Cause of death:
Relationship:
Date of birth:
❑ Heart Disease
❑ Cancer
❑ Stroke
❑ Diabetes
❑ Asthma
❑ Osteoporosis
❑ Other ____________
Age of onset:
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
❑ Yes ❑ No
If yes,
❑ Yes ❑ No
If yes,
Age at death:
Cause of death:
Relationship:
Date of birth:
❑ Heart Disease
❑ Cancer
❑ Stroke
❑ Diabetes
❑ Asthma
❑ Osteoporosis
❑ Other ____________
Age of onset:
_________
_________
_________
_________
_________
_________
_________
_________
_________
_________
❑ Yes ❑ No
If yes,
❑ Yes ❑ No
If yes,
Age at death:
Cause of death:
Adapted with permission

Creating Your Health Family Tree
After having conversations with each family member organize your family health
history into a pedigree chart.
Here’s How:
Cut out each family member’s Health Family Tree Information Box checklist
Arrange the checklists on a poster or large piece of paper in the following
manner. Do not tape or glue the checklists until the last step!
Starting with the oldest generation, place parents together.
This is Generation I.
Place the children of each set of parents below each couple in birth order.
This is Generation II.
Place the children of the members of Generation II below their parents in
birth order.
This is Generation III.
Continue adding generations in this manner until you have correctly arranged
all of your family members.
Tape or glue the arranged checklists to your poster or paper. Draw lines
between the checklists to indicate their relationships.
1
2
3
4
5
1
2
3
4
5
R.V.Raghavendra Rao

Name
Date
Family Traits and Traditions: A Make-a-Match Game
Traits can be inherited from a parent, or traits can be learned.
Family and cultural traditions often influence learned traits.
Can you think of a trait you have inherited? How about a trait
that you have acquired by learning or tradition? Play this
game with your family to discover some common traits and
traditions!
Preparation
Object of the game
R.V.Raghavendra Rao
Note to Families
We have been learning about “traits”
at school. Inherited traits are physical
characteristics that can be passed down
from parent to child. This family activity can
help your child learn to identify inherited and
learned traits.
• Cut out the game cards. You may want to glue or tape the pages to
heavy paper first.
• Use your memory to find the cards with matching pictures. The person
to collect the most matches wins!
Instructions
Hint
Cards with matching pictures have
different phrases. One card in
the pair describes a trait, and the
other card in the pair describes a
tradition.
1. Place the game cards face down and spread them out. Decide which member of your family will go first.
2. The first player turns over two cards, looking for a match. All players should have a chance to see the
pictures on the two cards.
3. Read each card. Decide whether it describes an inherited trait (something you are born with) or a tradition
(something you learn from others). Record your answer by checking the box next to “trait” or “tradition” .
4. If the pictures on the cards MATCH, the player keeps the cards. They then take another turn. If the pictures
on the cards DO NOT MATCH, the player does not keep the cards and turns them face down.
5. The next player turns over two cards, looking for a match. Continue to label each card as either a trait or a
tradition.
6. Play until all the matches have been found. The person to collect the most matches wins!

Name
Date
I have
attached
earlobes
I have
pierced ears
I can roll my
tongue
I like to eat
spicy foods
I have
dimples
I greet
others with
a smile
My natural
hair color is
brown
I use dye to
change my
hair color

Name
Date
I am left-handed
I use my
hand to
catch a ball
I am color-blind
I like to
create art
I have
allergies
I care for
a pet
I have
freckles
I lay in the
sun to get
a tan

Name
Date
R.V.Raghavendra Rao
We all have inherited traits that we share in common with others.
Families share many traits in common because parents pass down
inherited traits to their children. Yet, every person has a combination
of traits that is unique to them.
What traits do you share in common with others in your family? What
traits are unique to you? Do this activity with your family to find out!
** Individuals in your family do not need to be related to participate in this activity.
Preparation
Instructions
Note to Families
We have been learning about
inherited “traits” at school. These
are physical characteristics that
can be passed down from parent to
child. This family activity can help
your child learn to identify inherited
traits.
• Cut out the game cards. You may wish to glue or tape them on heavy paper first.
• Invite your family to sit in a circle. Hold up one game card at a time to show the picture of a trait. All family
members that have this trait should stand or raise their hand. Continue with each game card to find similarities
and differences among family members.
»» Did you have a trait in common with a parent?
»» Did you have a trait that a parent does not have?
»» Did each person in your family have a different combination of the traits described?
Once the group is familiar with all of the inherited traits described in this activity, try this second
activity!
• Shuffle the game cards and place the deck face down. Invite your family to stand up and form a circle. Draw a
card and hold it up to display the picture of the trait.
• All family members who have this trait should stay standing. Those who do not have the trait should sit down.
Once a person sits down, they should not get up again. Continue with each game card until only one person is
left standing.
»» How many cards did it take to find one person with a unique combination of traits?
• Shuffle the cards and play again as many times as you would like.
• Try this activity at a larger gathering of extended family or friends. Do you think more or less cards will be
needed before only one person is left standing?

Name
Date
R.V.Raghavendra Rao
Attached earlobes Can roll tongue Dimples Right-handed
Freckles Naturally curly hair Cleft chin Allergies
Cross left thumb
over right
Can see red &
green

Handy Family Tree
Materials needed
• One large piece of paper or poster
board
• Colored paper (one or two for each
member of your family)
• Scissors
• Pens or markers
• Tape or glue
Instructions
R.V.Raghavendra Rao
Note to Families
We have been learning about “traits” at school. Inherited
traits are physical characteristics that can be passed down
from parent to child. This family activity can help your child
distinguish between inherited and learned traits.
1 2
Trace the right and left hand of each family
member onto a piece of colored paper
Cut out the handprints
A family tree is a picture that shows members
of your family. It can include information about
each person. Do this activity to create your own
family tree!

Trait no one else in your family has
Trait shared with a brother or sister
Trait shared with a parent
Trait shared with a grandparent
On each finger of your left handprint list a trait (physical
characteristic) that you have inherited such as:
• eye color
• hair color
• dimples
• freckles
• chin shape (smooth or cleft)
• ability to roll the tongue
• earlobe attachment (attached or free)
• hairline shape on the forehead (smooth or pointed)
• height
R.V.Raghavendra Rao
On each finger of your right handprint, list a trait
that you have acquired or learned.
Glue or tape your family’s handprints above the trunk to form a tree.
Place the oldest person’s pair of hands at the bottom. Work upward
until you place the youngest person’s pair of hands at the top.
Optional
Word describing your character
Favorite game, sport or hobby
Favorite food
Favorite pet
3
4
5
Draw a tree trunk onto a large piece of paper or poster board.
• Add a small picture of each family member to the palm of one handprint.
Write their name, date of birth, and place of birth on the palm of the
other handprint.
• Include handprint shapes for family members who were not available
to draw their hands. See how your parents’ or grandparents’ favorites
compare to yours!

Name
Date R.V.Raghavendra Rao
TRAiTs bingo
Color or mark with an “x” the squares below when instructed to do so
The square marked “free” is a free space
B I N G O
Aunt I have
allergies
Straight
hairline Freckles Mother
I cross my
right thumb
over my left
when I clasp
my hands
Can not taste
PTC Curly hair Neighbor can
not taste PTC Straight hair
Father Grandmother Free Attached
earlobes Dimples
I have a
different
trait than the
person sitting
next to me
Cleft chin Can taste PTC Uncle Can not roll
tongue
Detached
earlobes
Shared trait -
Left
Trait in
common -
Right
I cross my left
thumb over my
right when I
clasp my hands
Least common
trait

Traits Bingo
Module
The Basics and Beyond:
An Introduction to Heredity
Bingo Questions
You may ask the questions in order, at random, or have students draw numbers.
1. Color the square marked I cross my right thumb over my left when I clasp my hands if this describes you.
2. Color the square marked Shared trait-Left if you share a trait with the person sitting to your left.
3. Color the square marked Least common trait if you have a trait that not many people in the class share.
4. Color the square marked Neighbor can not taste PTC if you sit next to someone who can not taste PTC.
5. Color the square or squares naming the relatives from whom you do not inherit traits
6. Color the square or squares naming the relatives from whom you do inherit traits
7. Color the square marked I have allergies if you have this trait.
8. Color the square marked Trait in common - Right if you and your neighbor to the right share a common trait.
9. Find the two squares for tasting, or not tasting, PTC and color the one that applies to you.
10. Find the two squares describing earlobes and color the one that applies to you.
11. Color the square marked Straight hairline if you have this trait.
12. Color the square marked Can not roll tongue if you have this trait.
13. Color the square marked I have a different trait than the person sitting next to me if this describes you.
14. Find the two squares describing hair texture and color the one that applies to you.
15. Color the square marked Freckles if you have this trait.
16. Color the square marked Dimples if you have this trait.
17. Color the square marked Cleft chin if you have this trait.
18. Color the square marked I cross my left thumb over my right when I clasp my hands if this describes you.

R.V.Raghavendra Rao
Generations of Traits - Instructions
In this activity you will track different traits (represented by colored pom-poms) through three
generations of “Ginger People”. You will need the Generations of Traits Worksheet to follow along.
1. With a partner, label six cups as shown:
Grandfather A Grandmother A Grandfather B Grandmother B
Mother Father
2. Arrange the cups as shown above and place six pom-poms in the cups, following the
directions below:
Grandfather A - red Grandfather B - yellow
Grandmother A - brown Grandmother B - green
The colored pom-poms are the traits that each of the grandparents have. Color the pom-pom
pictures on the Generations of Traits Worksheet to show the traits for each grandpar-ent.
3. Close your eyes and pick three traits from Grandfather A and three traits from Grandmoth-er
A and place them in the cup labeled Mother. These are the traits that Mother inherited
from her parents. Color the pom-pom picture on the worksheet to show the traits Mother
has.
4. Close your eyes again and pick three traits from Grandfather B and three traits from
Grandmother B, and place them in the cup labeled Father. These are the traits that Father
inherited from his parents. Color the pom-pom picture on the worksheet to show the traits
Father has.
5. Mother and Father have four children: Mary, George, Elizabeth and Carl. To determine
the traits that Mary will inherit from Mother and Father, close your eyes and take three
pom-poms from Mother and three pom-poms from Father. Color the diagram to show the
traits that Mary inherited.
6. Next, return the traits that you took from Mother and Father. (Look at your diagram if you
forget where each trait came from.) Now, close your eyes again and choose the traits that
George will inherit (3 from Mother, 3 from Father). Color the diagram to show George’s
traits.
7. Return the traits you took from Mother and Father and repeat the process to find the traits
for Elizabeth and then Carl.
8. Answer the questions on the Generations of Traits Questions sheet.
Name
Date

R.V.Raghavendra Rao
Generations of Traits - Questions
1. Would Mary, George, Elizabeth and Carl look identical to (have the same traits as) their
parents?
2. Did all four children inherit exactly the same traits or is there some variation?
3. How many of the four children inherited a trait from each one of the grandparents?
4. Is there a child that didn’t inherit a particular trait? If so, which trait (color) was it?
Name
Date

Module
R.V.Raghavendra Rao
Abstract Learning Objectives
Traits are observable
characteristics that are passed
An individual will have many
traits they share in common with
others.
An individual’s overall
combination of traits makes
them unique.
Some traits are more common
in a population than others.
Special Features
Includes a fun optional activity
in which students predict the
number of traits it will take to
distinguish a student volunteer
from everyone else in the class.
Includes a math extension in
which students calculate the
frequency of traits in their
classroom, then compare
their calculations with given
frequencies for the general
population.
Students take an inventory of their own easily-observable
genetic traits. Working in small groups,
they observe how their trait inventories differ from
those of others. Students record their observations
in a data table and make a bar graph to show the
most and least common traits in the group.
Logistics
Time Required
Class Time:
30 minutes
Prep Time:
20 minutes to review activity and make
copies of student pages
Materials
Copies of student pages
Appropriate For:
How to construct and read bar graphs
Grade 9-10

R.V.Raghavendra Rao
Module
Classroom Implementation
Activity instructions:
• Begin by demonstrating one of the traits listed in An Inventory of My
Traits: Survey (page S-1). Ask students who possess this trait to stand.
Point out the relative numbers of students standing and sitting for the
trait. Continue this process with 2-3 more traits.
Quantities
Per Student
• Explain that traits are observable characteristics we inherit from
our parents. Some traits are common in a population (our class)
while others are not. And, every person has a different overall
combination of traits that makes them unique.
• Divide students into groups of four or more. Have each student in
the group complete An Inventory of My Traits: Survey (page S-1)
to determine their unique combination of the traits described.
• After students complete the survey, have them tally their group
information on the data table (page S-2) and draw a bar graph
(page S-3).
• Optional: You may collect the traits data from the whole class
by creating a large wall chart (see example on the left). Have a
representative from each group fill in their data. Once all the data
has been collected, have the students make a bar graph from the
class data or make one large graph together.
Optional activity:
• Ask students to predict how many traits they would have
to look at on the Survey in order to identify any given
classmate as unique.
• Select a volunteer who would like to determine his or her
uniqueness. Ask all students to stand.
• Have the volunteer call out one of their traits at a time,
beginning with question 1 on the Survey and continuing in
sequence. For each trait, direct all students who do not
share that trait to sit down; students who share the trait
remain standing. Once a student sits down, they do not
get up again.
One copy of student pages
S-1 to S-3
Common Misconceptions
Students may think that the more common traits
are “better”, but this is not always the case.
Sometimes traits simply show up more frequently
in the human population.
More advanced students may think that dominant
traits are more common than recessive traits.
However, frequency has very little to do with
whether a trait is dominant or recessive. That is,
a dominant trait is not necessarily more common
and a recessive trait is not necessarily rare in a
population.

R.V.Raghavendra Rao
Module
• Continue in this way until the volunteer is the only one standing. Count the number of traits it took to
distinguish the volunteer from everyone else in the class. Compare this number with the students’
predictions.
• Repeat with several additional volunteers.
Math extension:
• Have students practice converting fractions to decimals, then decimals into percentages by calculatig the
frequency of the following traits in your classroom: tongue rolling, handedness and hand clasping.
∙ Students can then compare their calculated frequencies with those for the general population (provided in
the table below).
Example: # of students with the trait/# of students in the class x 100 = ________%
15 tongue rollers / 21 students in the class x 100 = 71%
Trait Frequency in General Population*
Tongue rolling Can roll tongue – 70%
Cannot roll tongue – 30%
Handedness Right handed – 93%
Left handed – 7%
Hand clasping
Left thumb on top – 55%
Right thumb on top – 44%
No preference – 1%
Standards
*Frequencies for traits are from
Online Mendelian Inheritance In Man
(see http://www.ncbi.nlm.nih.gov/
omim/).
NCERT/CBSE
Grades 8-9:
Content Standard C: Life Science - Reproduction and Heredity
• Every organism requires a set of instructions for specifying its traits. Heredity is the passage of
these
instructions from one generation to another.
• The characteristics of an organism can be described in terms of a combination of traits.

R.V.Raghavendra Rao
Module
Additional Resources
Visit the Teach.Genetics website to get more great
resources like these!

An Inventory of My Traits - Survey
What combination of these traits do you have? Complete the survey to find out.
1. I have detached earlobes Yes No
2. I can roll my tongue Yes No
3. I have dimples Yes No
4. I am right-handed Yes No
5. I have freckles Yes No
6. I have naturally curly hair Yes No
7. I have a cleft chin Yes No
8. I have allergies Yes No
9. I cross my left thumb over my Yes No
right when I clasp my hands
together
10. I can see the colors red and green Yes No
( I am not color blind)
11. The hairline on my forehead is Yes No
straight.
12. I am a: Male Female
Name
Date

R.V.Raghavendra Rao
An Inventory of My Traits - Data Table
How many people in your group have each trait?
Fill in the data table below by counting the number of people who marked “yes” and
the number of people who marked “no” for each trait.
TRAIT YES NO
Detached earlobes
Tongue rolling
Dimples
Right-handed
Freckles
Naturally curly hair
Cleft chin
Allergies
Cross left thumb over right
See the colors red and green
Have a straight hairline
Name
Date

Name
Date
An Inventory of My Traits - Graph
Make a bar graph showing how many people in your group answered “yes” for each trait.
Be sure to label each trait under the bar you draw for it.
# of students
5
4
3
2
1
0
Traits

PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
PTC tasting:
yes no
attached unattached
yes no
earlobes:
tongue rolling:
R.V.Raghavendra Rao

R.V.Raghavendra Rao
A Recipe for Traits
A set of instructions called DNA makes a “recipe” for traits in all
organisms. Information in a DNA strand is grouped into small segments.
Each segment is made of even smaller units (like recipes are made of
words, and words are made of letters). Differences in the DNA “alphabet”
are what make differences in traits (just like a different sequence of
letters makes different words, and a different recipe).
Name
Date
Follow the directions below to create a DNA recipe for a dog. Using the Dog
Traits Key, read your DNA recipe and make a drawing of your dog showing all of
its traits.
Directions:
1. Make sure you have an envelope containing “Dog DNA”.
2. Determine the first trait of your dog (body shape) by randomly picking a
piece of dog DNA out of the envelope.
3. Look at the symbols on the DNA strip you have chosen. Match the pattern to
one you see on the Dog Traits Key for body shape.
4. Circle the picture for body shape that matches the DNA piece that you
picked.
5. Set the piece of DNA aside and repeat steps 1-4 for the next trait on the key.
6. After circling the matching picture, tape the second piece of DNA to the first
to make one long strand. This will become the DNA recipe for your entire
dog.
7. Repeat these steps for each of the traits listed on the Dog Traits Key.
8. When you have finished, draw your dog with all of its traits (the traits you
have circled on the Dog Traits Key) on a separate piece of paper.
9. As instructed by your teacher, hang up the picture of your dog along with its
DNA recipe (the DNA pieces you chose attached in a long strand).
Is your dog different from or the same as others in the class?

Body Shape
Head Shape
Ears
Legs
Dog Traits Key
Small, Thin,
Long, Straight
Large, Thin,
Long, Tapered
Medium, Very
Muscular, Short
Large Semi-
Muscular, Straight
Long, Thin Flat Short Droopy
Small, Pointy Big Droopy Medium Square Medium Droopy
Long, Thin Short, Stubby Medium Stocky, Muscular
Name
Date
R.V.Raghavendra Rao

Eyes
R.V.Raghavendra Rao
Dark Brown Light Brown Blue Green
Tail
Coat Color
Hair
Short Nub Long with
Short Hair
Pompon Tipped Long and Bushy
Brown Black Red-Brown Yellow
Curly, Short Straight, Short Straight, Long Wavy, Long
Name
Date
Dog Traits Key

DNA Strips A
A Recipe for Traits
Module
R.V.Raghavendra Rao

DNA Strips B
A Recipe for Traits
Module
R.V.Raghavendra Rao

DNA Strips C
R.V.Raghavendra Rao
A Recipe for Traits
Module

DNA Strips D
R.V.Raghavendra Rao
A Recipe for Traits
Module

R.V.Raghavendra Rao

Introduction to heredity curriculum final

Introduction to heredity curriculum final

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