KARYOTYPE is a picture of
A __________
an organism’s chromosomes
Chromosomes that determine
the sex of an organism =
_________________
Sex chromosomes
All other chromosomes =
_________________
autosomes
Humans have two sex chromosomes
X
y
and _____
44 autosomes
SEX DETERMINATION
XX = female
Xy = male
Who decides?
Mom can give X
Dad can give
X or y
X
X
X
XX
XX
y
Xy
Xy
Dad determines sex of the baby.
SO ____
If dad gives X with mom’s X = girl
If dad give y with mom’s X = boy
PEDIGREES
_______________are
diagrams
that show how are genes passed on
in families over several generations
Pedigree

Chart that shows relationships within a
family
Your Pedigree
Complete a pedigree for at least 3 generations of your family (including
you) for the following traits:
Widows peak - dominant
Cleft chin - dominant
Dimples - dominant
Tongue rolling- dominant
Ear lobe attachment – free lobe is dominant, attached is recessive
Freckles - dominant
Mid-digital hair - dominant
Hitch-hiker’s thumb - dominant
Bent little finger - dominant
P.T.C. paper taster - dominant
Your Pedigree







Circles represents female
Squares represents male
Colored shapes indicate recessive trait
Non-colored shapes indicated dominant trait
Write out the genotype for each trait for each
person
Should have 10 shapes per person
BONUS – add a unique or interesting trait that
your family has
Grandparents
1st generation
aa bb
Parents 2nd
generation
aa Bb
aa Bb
aa bb
Siblings
and me 3rd
generation
Key
Female
Male
recessive
aa bb
Key
A- Widow’s Peak
B- Cleft Chin
.......etc….