.Lane Tech College Prep High School .
Department of Biological and Earth Sciences
BIOLOGY 2nd SEMESTER
PROJECT
Family Pedigree Research
Page 1 & 2
Explanation and instructions
Page 3
Assembly details and parent help page
Page 4
Common traits that are easily observed
Page 5
Symbols for constructing family and pedigree trees
Page 6
Internet pedigree links – find help here!
Page 7
Sample scoring rubric for self-evaluation
A Parent / Family Involvement Project
Supervision and assistance Mandatory in several phases
Project design in alignment with National Science Education Standards and Illinois State Goals
By Keating, Keating, Dignam & Hayden Instruction Consortium
BIOLOGY 2nd Semester PROJECT.
Due: ___-___-___ or earlier.
Ask your instructor!
Family Pedigree Project.
Much of this project will be started / explained / developed as in-class activities while the class explores
principles of autosomal and X-linked inheritance. You will need help and assistance from your parents in
completing the first and fourth phase of this project! Do not wait to ask for help. Start immediately.
FIRST: You need to find out the names of persons in your family, on both parental sides. You will
construct a family “tree” showing the following generations:
I.
Great-grandparents (8)
II. Grandparents (4) and their siblings
III. Your parents (2) their siblings and mates
IV. You, siblings, cousins and mates
V. Nieces, nephews, and children of your cousins
Your completed tree must show four or more of the above generations, and include at least 36 individuals.
You must have information from both sides of your family. It is normal for a family “tree” to be asymetrical.
You will likely have more individuals on one side. It does not matter if parts of your family are separated by
divorce or geography. You are still genetically related to these individuals. They are a part of your “tree”.
If you cannot meet the requirements stated in the above paragraph:
 You must obtain information from someone else not in your class
and use their family tree for the assignment.
 You are responsible for all data collection and pedigree tree
development just as if it were your family tree.
SECOND: Use the rules and symbols your class / workgroup obtained in-class from the Internet to
build your framework tree. Names should be shown on this page, and all rules and symbols followed
except: No traits will be shown. All symbols (circles and squares) will be un-shaded. (empty) This is
your family tree, which will serve as a “skeleton” or “shell”. It is not a pedigree tree.
Points to remember:
 Generations should be marked with a Roman numeral on the left of your tree, and all symbols
in that generation should be on the same horizontal level. e.g.: III
 Use a ruler / straightedge to make all lines. Use a circle template or other round object to make
round symbols. Freehand drawn trees are unacceptable.
 Most trees are very wide, and symbols must not be less than ¼” across. You may need to tape
two or more sheets of paper edge-to-edge to accommodate your tree. The left-most page must
be three-hole punched. Subsequent pages must have their width reduced from 8 ½” to 7 ¼”.
Use a ruler to carefully mark and cut the sheet(s). This method will permit the finished tree to
fold and unfold neatly while fastened within a three-clip report folder.
THIRD:
Make three identical copies of your “tree” without the names. These will be used for the
pedigree traits you choose to investigate. The copies must line up exactly with your original tree.
Photocopies made at 100% size are a good way to do this. Remember, no names on these three! They
must be three-hole punched, and fold into a report folder just like the original. (Hint: Make extras!)
FOURTH: Select three of the nine visually observable traits you have obtained information about
during class from the Internet. The traits you select must appear in some of the persons within your
family. Do not pick traits that appear in all or none of your family members. Doing so will produce a
pedigree tree unacceptable for this project. (The pedigree tree would be all blank or all shaded!)
FIFTH: How to organize and collect your data: Make a vertical column name list of the persons on
your tree. List them in order from left to right on your tree, starting with generation I. (This will make it
easier for you to transfer data you collect to pedigree trees.) Draw three vertical columns next to your
name list, and title them with the traits you selected. In each column, mark Y (Yes, they express the trait.),
Page one
N (No, they do not express the trait.) or ?, indicating you are unable to obtain data. (Deceased, no one
remembers, etc.) The ? data should be limited to a few individuals, usually great-grandparents.
 As an alternative, you may use a spreadsheet or other computer program to organize your data.
FIFTH: Label / title each of the three blank trees with one of the three names of the traits you
have chosen for this project. (One trait name goes on each tree.) Shade in the boxes / circles on
each pedigree tree to correspond to the data you have collected for that one trait. Remember, at
this point you do not know who is a carrier. You only know who expresses the trait, and those
boxes / circles are completely filled in. All others are empty.
SIXTH: Start adding allele data to each pedigree tree. You need to carefully read and understand
the trait genotype information you obtained from the Internet. Each of the nine traits has specific
letters that will be used to represent the alleles. Some traits are recessive, others dominant or codominant, some sex-linked. You must use the correct letter symbols for the alleles!!!
 If a chosen trait is recessive you know that those who express that trait must be homozygous,
and you can write both alleles (two lower-case letters) below their symbol. (e.g.: a a ) You
also know that one of the alleles came from each parent, so a parent who does not show a
recessive trait, (N, or “No” on your phenotype data list) but has offspring that do must be
heterozygous. You can then write both alleles below their symbol. (e.g.: A a ) These
individuals are carriers of the recessive trait, and can be then be half-shaded. Children from
carriers who do not show a recessive trait may be either homo or heterozygous dominant. You
need to carefully examine your pedigree tree to determine this. If it can be determined, enter
both letters representing the alleles below their symbol. (e.g.: A A or A a ) If it is not
possible to determine, only enter one upper case letter and a blank with a question mark under
their symbol. (e.g.: A ? ) Caution! Entering a question mark for the second allele of a person
whose genotype can be determined will make your pedigree tree problem wrong and invalid.
It is your responsibility to apply logic and check the correctness of your work!
 If a trait is dominant, you do not immediately know from the phenotype data you collected if
the person is homozygous or heterozygous, so you can only enter one upper case letter and a
blank with a question mark under their symbol. (e.g.: B ? ) You do, however, know that
individuals who do not show dominant traits must be homozygous recessive, so you can fill in
both alleles under the symbol representing them. (e.g.: b b ) You also know that parents of
these homozygous recessive individuals must each have contributed one recessive allele,
therefore they must be B b if they show the trait. This deductive logic will remove the ? from
some individuals on the tree. Caution! Leaving a question mark for the second allele of a
person whose genotype can be determined will make your pedigree tree problem wrong and
invalid. It is your responsibility to apply logic and check the correctness of your work!
 Co-dominant traits can traced through your pedigree tree in a similar matter to those explained
above. Start by shading the symbols for those who express the trait, and then pencil-in all
genotype possibilities that would cause them to express the trait. Use logic, and Punnett
squares, to refine the possible genotypes. Remember to use the correct symbols for the alleles.
When you have finished a tree with co-dominant traits, there should be no almost no ? allele
symbols. Leaving a question mark for either allele of a person whose genotype can be
determined will make your pedigree tree problem wrong and invalid. It is your responsibility
to apply logic and check the correctness of your work!
 X-linked recessive traits pose a challenge in identifying female carriers. Use logic, and
Punnett squares, to refine the possible genotypes. Remember to use the correct symbols for
the alleles. Failing to identify or incorrectly identifying carriers will make your pedigree tree
problem wrong and invalid. It is your responsibility to apply logic and check the correctness
of your work!
When you are finished, each pedigree tree will have a title describing the trait across the top of the page
and will show allele data for each symbol. Individuals expressing the trait are shaded, carriers ½ shaded.
Page two
Name ________________________________Div. _______ Date ___________ Class Number _________
BIOLOGY 2nd Semester
Family Pedigree Project.
Due: ___-___-___ or earlier.
Ask your instructor!
Assembly of your finished pedigree project:
1. Clear-cover three-clip report folder
2. Cover page:
 Title (Family tree and Pedigree project)
 Your Name, Division Code
 Your three-digit class number
 Date of submission
3. Single page showing pedigree symbols and explanation of the three traits you chose.
4. Data list (may be several pages)
5. Your family tree with Names.
6. Pedigree tree number one. NO names. Use generation (I, II, III, IV, V) and individual (1,2,3,4…)
7. Pedigree tree number two.
”
”
8. Pedigree tree number three.
”
”
9. 250 word (minimum) word-processed essay. Discuss the following: (Check the rubric!)
 Why you chose the traits featured in your project
 How you went about collecting info for your family tree
 Challenges encountered in collecting data
 Your analysis of probabilities for “?”alleles you could not solve
 What you learned through this project
 Do not explain how you solved / determined the genotypes for the pedigree trees.
10. Parent verification (below).
*********************************************************************************
Dear parents:
Thank you for assisting your child with this project. Please
help by checking the project assembly list on this page and
asking your child to explain their completed project to you.
If you have comments / suggestions concerning this project,
please tell me about them.
___________________________________________________
___________________________________________________
___________________________________________________
___________________________________________________
__________________________________ ______________
Parent Signature
Date
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Common Human Traits - You may use others only with instructor approval!
Use the internet to find visual examples of these traits Tongue Rolling
Dominant trait
YES, Roller = RR or Rr (Start with R?) NO = rr
Attempt to roll your tongue into a U-shape, in which the sides of your tongue are curled upwards. Tongue rollers
carry a dominant gene R. Non-tongue rollers are homozygous recessive (rr). No carriers
Widow's Peak Dominant trait YES, Widows’s Peak = WW or Ww (Start with W?) NO = ww
A dominant gene W causes the hairline to form a distinct downward point in the center of the forehead (like Richard
Nixon). Baldness will mask the expression of this gene. If you have a Widow's Peak, you have at least one dominant
gene. No downward point of the hairline, you are homozygous rec. (ww). No carriers
Earlobe Attachment Homozygous Recessive trait YES,Attached = ee NO = EE or Ee (Start with E?)
The inheritance of a dominant gene E results in the free or unattached earlobe. If the lobe is attached directly to the
head, the individual is homozygous recessive, and the ee genotype is present. Other genes, working alone or together,
affect the size and shape of the earlobe and are not considered here. We are only looking at whether the earlobe is
attached or not. Use the appropriate symbol for carriers!
Hitchhiker's Thumb Homozygous Recessive trait YES, 45oThumb = hh NO=HH or Hh (Start with H?)
Some individuals can bend the last joint of the thumb backwards at about a 45 degree angle. These individuals are
homozygous for a recessive gene, hh, but there is considerable variation in the expression of the gene. For our
purposes, we shall consider those who cannot bend at least one thumb backwards about 45 degrees, are carrying the
dominant gene, H. Use the appropriate symbol for carriers!
Bent Little Finger
Dominant trait
YES, Bent = BB or Bb (Start with B?) NO = bb
The dominant gene, B, causes the terminal bone of the little finger to angle toward the fourth (ring) finger.
Individuals whose little fingers are straight possess the homozygous recessive condition, bb. Check for this
characteristic by laying your hands flat on the desk and relaxing them. No carriers
Mid-digital Hair
Dominant trait
YES, Hairy = MM or Mm (Start with M?) NO = mm
The presence of hair on the middle segment of the fingers is caused by a dominant gene, M. The homozygous
recessive condition, mm, results in the lack or absence of hair on the middle segments of the fingers. Examine your
hands closely since the hairs may be small in length and light in color. No carriers
Facial Dimples Dominant trait YES Dimples = DD or Dd (Start with D?) NO = dd
The inheritance of cheek dimples is controlled by a dominant gene, D. The homozygous recessive, dd gene condition,
lacks the ability to express facial dimples. No carriers
Long Big Toe Length Homozygous Recessive trait YES, long = hh NO = HH or Hh (Start with H?)
The length of the big toe is governed by the dominant gene, H. Individuals whose big toe is shorter in comparison to
the second toe possess the dominant gene. The inheritance of the homozygous recessive, hh, results in the big toe
being longer than or equal to the second toe. Use the appropriate symbol for carriers!
Index Finger Length WARNING!! Sex-Influenced (NOT sex-linked) THIS IS VERY DIFFICULT !!
If your index finger is shorter than your ring finger on the same hand, you have a short index finger in relationship to
the length of your ring finger. The gene for short index finger, S', is also sex-influenced in its expression (like
baldness). It is dominant in males and recessive in females. That is, while all S'S' individuals have short index
fingers, S'S'' males show short index fingers and S'S'' females do not. The gene for long index finger, S'', is
dominant in females. Is it possible for a homozygous individual to be a CARRIER for the opposite sex
offspring? THINK.
MALES with short index finger may be S’S’ or S’S’’ ( S’ Dominant in MALES ONLY ) Start with S’S?
MALE/Long MUST be S’’S’’
FEMALES with short index finger MUST be S’S’ ( S’ Recessive in FEMALES ONLY )
FEMALE/Long may be S’S’’ or S’’S’ Start with S’’S?
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You will need to make your own symbol legend page for your report!
These are commonly used. Your instructor may make changes. ASK!
SYMBOLS:
Female, Male who do not express trait
Female, Male who express trait
Female, Male who are carriers for a trait
Deceased Female, Male
Stillbirth
SB
SB
Sex unknown
P
P
P
Pregnancy
Miscarriage or terminated pregnancy
Identical twins (same sex does not prove “identical” status)
Proper term: Monozygous twins – from one zygote
Fraternal twins (sexes may be F/F, F/M, or M/M)
Proper term: Dizygous twins – from two zygotes
LINES:
= Generation
= Parents
= Adoption
= Consanguineous parents
I
1
= Divorced
3
2
4
= Siblings Note- one adopted!
P
II
1
2
3
4
5
= Proband
NOTE: A proband is the person who prompted the
pedigree analysis. It could be to find a possible genetic
defect, or for legal reasons. In the case of this project it
is you, the student! Place this arrow on your symbol.
MISCELANEOUS:
Use Roman numerals to show generations, Arabic numerals to identify individuals.
See examples above, in RED. Order siblings oldest (left) to youngest (right). Page five
Internet links – Typing “pedigree analysis” into Google or Yahoo search engines produces
thousands of links! You can also try ‘pedigree traits’, pedigree illustrations’, ‘genetics’, etc.
Here are just a few… If you cannot access the links from this page, then you
must COPY/PASTE or manually type the addresses into your browser.
Pedigree Analysis
http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/Bio%20101%20Laboratory/Pedigree%20Analysis/PEDIGREE.HTM
Pedigree lab with some illustrations
http://www.accessexcellence.org/AE/AEPC/WWC/1994/traits.html
Alkaptonuria pedigree
http://www.people.virginia.edu/~rjh9u/alkap.html
X-linked inheritance
http://biology.kenyon.edu/courses/biol114/Chap02/sex_link.html
Steps for solving pedigree problems
http://www.people.virginia.edu/~rjh9u/pedhint.html
Another instructor’s lab with MANY MORE traits & alleles (second page)
http://www.starsandseas.com/SAS%20Genetics/SAS%20Heridity/Family%20Pedigree%20With%20Traits.pdf
Y-linked trait – Guys only!!
http://wsrv.clas.virginia.edu/~rjh9u/hairears.html
A Pedigree of Hemophilia in the Royal Families of Europe
http://wsrv.clas.virginia.edu/~rjh9u/roylhema.html
Pedigree of an X-Linked Recessive Trait – Colorblindness
http://wsrv.clas.virginia.edu/~rjh9u/xped.html
Where’s Wanda’s Mom? Practice examining traits – includes some illustrations of common traits
http://fog.n4h.org/f32.htm
Cleopatra, lineage of maternal consanguineous relationships – within this pedigree problem set- has answers to problems
http://www.mansfield.ohio-state.edu/~sabedon/biol1128.htm#A7
Dominant and recessive ear wax, hairy knuckles, left/right hair whorl, check this site. Illustrated!
http://www.uic.edu/classes/osci/osci590/5_3SimpleHumanNon-MetricTraits.html
As you explore and find others, write down comments and the web addresses
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Name ______________________________Div. _____ Date ___/___/___ Class _______ Your instructor’s name_____________________
Grading Rubric – Family Pedigree Project Ask your instructor for point / grade values!
_____ points.
_____ points.
_____ points.
Criteria
Data Table
_____
points
Pedigree
_____
points
Organization
_____
points
Aesthetics
_____
points
Essay
_____
points
Data is complete for 36 +
individuals, 3 traits for 4 +
generations properly &
neatly done, in order, easy to
understand, data is wordprocessed or spreadsheet
Data is completed for 36+,
Includes 3 traits for 4 generations
somewhat organized, handwritten list
or table
Incomplete / Missing parts
Less than 36 individuals with Y or
N data, the required 36 individuals
include several “?”s (? / data!)
Erroneous data, does not fit tree.
Pedigrees are neatly drawn
Correct symbols and color
coding are used
All pedigrees complete to 5
generations, No errors
Pedigree is somewhat confusing, a
few errors.
Most symbols are correct with color
coding
Pedigrees complete to 4 generations
Pedigree is neatly organized
Symbols & traits in project
clearly explained, with all
possible pheno & genotypes
All pages in proper place
Project is somewhat organized but
the reader has a hard time
determining relationships or
generations
Symbol or trait explanation minimal
A page or two not in proper place
Project is easy to examine, pages fold
in and out easily
Very minor appearance defects in
presentation
One or more incomplete
Symbols used incorrectly or
missing
Generations do not line-up
Titles missing on pedigree(s)
3 or less generations shown
5 or more errors total
Not organized, very confusing to
reader
Assembly instructions not
followed.
Overall project is appealing
to reader with an attractive
cover. Clean, unwrinkled,
not dog-eared, new,
professional appearance.
Easy to read and follow
400 + word essay is clear.
Includes hypothesis for
unsolved (“?”) genotypes for
those family members AND
Includes hypothesis of
family origin of a recessive
trait Neatly word-processed
250+ word essay is somewhat clear.
Does not include clear hypothesis for
unsolved “?” individuals and/or
hypothesis of origin of family
recessive trait
Not attractive
Minimal effort in making cover
and formatting
Wrinkled, or smuged, or dog eared
on more than one page
Pages do not fold in properly
Essay is incomplete or unclear.
Parts missing
Less than 250 words
No hypothesis made about what
was learned.
Poorly word-processed
Neatly word-processed
Entire project = ZERO if any of the following apply: Late; any page missing; cover and/or essay not word-processed.
Page seven