Download ear lobe attachments, tongue rolling, hitchhiker`s thumb, and mid

Take Home Lab: What Are Some Traits in Your Family?
This lab should follow the study of pedigree designs and human genetics. Two pedigree designs will be prepared of your
family's genetics. You will construct the pedigree representing at least three generations. The traits that you will follow
are: ear lobe attachments, tongue rolling, hitchhiker's thumb, and mid-digital hair. Begin at the bottom of the pedigree
design with you and your genetic brothers and sisters. A square is used to represent a male person and a circle a female.
Shading of either a square or a circle indicates the possession of the recessive allele trait. Each marriage or mating
generation is indicated by a Roman numeral. The square and circle are joined by lines indicating marriage or mating
relationships. Please review the pedigree shown to understand how relationships may be indicated.
PROCEDURE AT HOME:
Take this lab home and make two pedigree designs of your family for the traits listed in Part C. You may go
back as many generations as you can determine; for example, to great-grand parents. Draw each pedigree on a
separate paper. If you have a relative you cannot find or who is unreachable, put a question mark between the
parentheses to the right of his/her name.
1. In the blank below each person in the pedigree (circle or square), give your first name and the first name
of each of your genetic relatives.
2. In the parentheses to the right of the person's name, give what genotype you think he or she has.
[Example Joe (Ff) or Jane (SS) or Sue (?)]
3. Remember, Part A is only a picture example listing the family pedigree design method and your actual
family pedigree will vary.
4. If grandma or grandpa or uncle George is out of town, try calling them on the weekend and have them
check their genetic traits for you.
TRAITS TO FOLLOW: choose 2
1. Ear lobe attachment: (See Fig. 1) The ear lobes may either hang free or be attached directly to the side of
the head. The gene for the free or unattached ear lobe trait is dominant (F), while attached earlobes are
caused by having two recessive genes (ff).
2. Tongue rolling: (See Fig. 2) Some people have the ability to roll their tongue into a distinct U-shape
when they extend their tongue from their mouth. This ability to roll the tongue is due to a dominant gene
(R). Those who have the two recessive genes (rr) can only curve their tongue slightly.
3. Hitchhiker's thumb: (See Fig. 3) People with two recessive genes (ss) for hitchhiker's thumb can bend
the distal joint of their thumb back so that it forms an angle of almost 45 degrees. This would be
hyperextension of the thumb. People with a dominant gene (S) cannot do this and could be called a
straight thumbed person or close to it.
4. Mid-digital hair: (See Fig. 4) The mid-digital hair trait is determined by a dominant gene (M) for each
finger causing hair to grow on the top of that finger. The trait is carried by a set of five alleles and will
cause hair to grow on one finger, two fingers, etc., depending on what allele you inherit. People who
have no hair on the digital part of their fingers carry all recessive genes (mm).
PICTORIAL VIEW OF PART C: