DOMINANT AND RECESSIVE
TRAITS
ATTACHED / UNATTACHED EARLOBES
UNATTACHED
DOMINANT
ATTACHED
RECESSIVE
ROLLING YOUR TONGUE
ROLLER
DOMINANT
NONROLLER
RECESSIVE
WIDOW’S PEAK
WIDOW’S PEAK
DOMINANT
STRAIGHT HAIRLINE
RECESSIVE
HITCHHIKER’S THUMB
STRAIGHT THUMB
DOMINANT
HITCHHIKER’S THUMB
RECESSIVE
PINKIES
BENT PINKIES
DOMINANT
STRAIGHT PINKIES
RECESSIVE
CLEFT CHIN
CLEFT
NO CLEFT
DOMINANT
RECESSIVE
SECOND TOES
LONGER SECOND TOE
DOMINANT
SHORTER SECOND TOE
RECESSIVE
NUMBER OF FINGERS
SIX FINGERS:
POLYDACTYLY
FIVE FINGERS
DOMINANT!!!!
RECESSIVE
• A family tree traces a family name and various family
members through successive generations.
• Through a family tree, you can identify the
relationships among your cousins, aunts, uncles,
grandparents, and great-grandparents.
• A pedigree is a family tree that traces an inherited trait.
• It is made up of a set of symbols that identify males
and females, individuals affected by the trait being
studied, and family relationships.
Pedigree Symbols
Ended Relationship
Line
Male
Relationship Line
Female
Parent/Children Line
Affected male
Affected female
Male carrier of a recessive trait
Female carrier of a recessive trait
• The generations are
identified in sequence by
Roman numerals
• Each individual is given a
number. It always begins
back at #1 for each
generation, moving left to right.
• If you are tracing
a simple
Dominant trait,
people will either
be shaded or they
won’t
• What would have to be the genotype of the people
that are not shaded if you are tracing a Dominant
trait?
• If you are tracing a Recessive trait, you will need to
shade in the people that have the trait, AND halfshade your known carriers.
Begin with a family tree….
And then convert it into a pedigree.
1. You can either use your family or a friend’s…if you are adopted you
can still use the adoptive family.
2. Choose which side of the family you want to track (mom’s or dad’s)
3. Choose which generation you want to begin with (keep in mind, you
must use three generations AT LEAST)
4. Choose an allele to track- ONLY ONE!
If you choose right-handedness, you’ll only indicate people that use
their right hands….you will NOT indicate people who use their left (it is
implied)
□
Ο□□
I
1
□Ο
II
1
III
2
3
4
5
Ο
2
Ο
6
□Ο Ο
1
2
3
5
6
7
7
8
9
10
11
12
Ο Ο□
□Ο Ο □
4
□ Ο Ο □□ Ο □
11
Ο □Ο
8
9
10
12
13
□
13
15
Ο
14
Then you can go back and change the names to boxes and circles, and use
the relationship lines the pedigree calls for.
Remember to use Roman Numerals for generations and numbers for each
person in a generation
My family is so ginormous, I probably should have put it on a poster (good
idea for those with big fams….more room to work with…cause I even left
people out…
□
Ο□□
I
1
□Ο
II
1
III
2
3
4
5
Ο
2
Ο
6
□Ο Ο
1
2
3
5
6
7
7
8
9
10
11
12
Ο Ο□
□Ο Ο □
4
□ Ο Ο □□ Ο □
11
Ο □Ο
8
9
10
12
□
13
15
Ο
14
Once you have the relationship lines, now research your trait and shade in
your affected and carrying relatives.
For my trait- anxiety is DOMINANT
13
□
Ο□□
I
1
□Ο
II
1
III
2
3
4
5
Ο
2
Ο
6
□Ο Ο
1
2
3
5
6
7
7
8
9
10
Ο Ο□
□Ο Ο □
4
□ Ο Ο □□ Ο □
11
Ο □Ο
8
9
12
For the last part of the visual, I marked deceased relatives.
12
13
□
13
10
11
15
Ο
14
Next, make a key of the symbols you used in your pedigree.
You do not need to include symbols not shown in your visual.
Key
□
Male Relative
Ο
Female Relative
□Ο
□Ο
□Ο
□Ο
□
Relationship
Ended Relationship
Fraternal Twins
Those blessed with high anxiety
Deceased
Purpose of Project:
Pedigree Project
To learn how to read and create a pedigree.
To learn how to trace an inherited trait.
Important Points to remember:
You do not have to trace a trait in your own family.
There needs to be at least 3 generations shown.
There needs to be at least 8 family members.
**You can leave people out if it gets too big or too complicated.
Rough Draft is due: NEXT THURSDAY 12/8 WHEN YOU WALK IN
- complete the family tree and answer the questions on the rough draft page.
- If you do not do this, I will notify home that you did not show proof of project work and
will deduct 10 points from your final grade.
- On 12/8 you ONLY need to turn in your rough draft paper, no binder necessary yet
Final Project is due: Friday, Jan. 6th- It is a TEST GRADE!!!!
- In your binder: TOC entry, pedigree chart, key, explanation, rough draft, and rubric
- Use your rubric as a checklist.
Websites on dominant and rec. traits.
http://www.blinn.edu/socialscience/LDThomas/Feldman/Handouts/0203hand.htm
http://www.ncbi.nlm.nih.gov/sites/entrez?db=omim
http://www.highlands.edu/academics/divisions/socialcultural/psych/johnson/hnd-domrec.htm
Pick one: Attached/Free Ear lobes,
Hitch-hiker’s thumb,
cleft chin,
dimples,
Curling tongue,
Widow’s Peak,
Longer second toe,
nearsighted (rec),
farsighted (dom.),
double jointedness (dom.),
right (dom.) or left (rec.) handedness,
freckles…..
***If there is another trait that runs in your family and you would like to use that
for your project, please make sure to get it approved before beginning the project.
I
Doreston
+
Lollé Irene
Decide where you want to start, keeping in mind you need to do AT LEAST 3 generations.
II
Michael—Pam
Kay—Joe
Jim
Janet —Ricky
—Marcia
Susan —?
Mark
Mary —Jay
Then write out the second generation of siblings only, first.
Then you can add in spouses, so you can see how much room you will need. REMEMBER:
You don’t have to include all relationships. I chose to just use relationships in which
children were born.
Jason
Tammy
III
James
Katie
Vanessa
Steph. Allison Damon
Alex
Sarah
Dan
Rita
Hollye
Michael
Adam
Rebecca
Then write out the third generation.
After that add in spouses if necessary.
Then you must pick out a trait you want to trace. You can do this by
asking questions, looking at pictures, ect.
Pick something that is ruled by simple dominance…I have a list.