1. Humans have 23 pairs of chromosomes, including one pair of sex chromosomes that determine gender (XX for females and XY for males). 2. A karyotype is created by photographing chromosomes during cell division and pairing them to identify any abnormalities. 3. Pedigrees are family trees that show genetic traits and can help genetic counselors understand genotypes within a family. 4. There are four main human blood types (A, B, AB, and O) determined by the presence or absence of antigens on red blood cells, and a person's blood type affects their ability to donate and receive blood.

1. Human HeredityHuman Heredity
The Human GenomeThe Human Genome

2. Chromosomes
• Humans have 46 individual or 23 pairs
• 1st-
22nd
pairs are called Autosomes or
Body Chromosomes
• The 23rd
pair are the Sex
Chromosomes because they
determine an individuals’ sex

3. XX= Normal Female
XY = Normal Male
• The Y chromosome is
about ½ the size of a
X chromosome
• Sex linked genes are
located on the X or Y
• Sex linked genes are
expressed in males
even if they are
recessive

4. Karyotype- a picture of
all chromosomes in pairs
• Scientist photograph chromosomes
during Mitosis, cut the pictures, and
then pair them to make a Karyotype

5. Human Karyotype:

6. Pedigrees
• A pedigree is a chart that shows the
relationship within a family
• Genetic Counselors analyze these
charts to understand the family’s
genotypes

7. Square = Male
Circle = Female
Horizontal Line = Marriage
Vertical Line = Offspring
Shaded = Has the trait
Not Shaded = Does NOT have trait
Half Shaded = Carrier of trait

8. Human Blood Types
Pheno: Geno:
A IA
IA
Homo or IA
i Hetero
B IB
IB
Homo or IB
i Hetero
AB IA
IB
Hetero
O i i Homo

9. 1. A can donate to A & AB
2. B can donate to B & AB
3. AB can ONLY donate to AB
4. O can donate to A, B, AB, & O
1. A can receive from A & O
2. B can receive from B & O
3. AB can receive from A, B, AB, & O
4. O can ONLY receive from O

10. 1. AB is called the Universal Acceptor
2. O is called the Universal Donor
3. Knowing a person’s blood type is critical
because it could be FATAL
4. Rh factor named for “rhesus monkey”
the animal in which it was discovered is
the (+) & (-) factor.
5. (+) is dominant & (-) is recessive
6. (-) can give to (+)
7. (+) can NOT give to (-)

11. 1. Nondisjunction – failure of
chromosomes to separate resulting in
an extra or deleted chromosome
2. Gene Therapy – When an absent of
non-working gene is replaced with a
normal healthy gene using Genetic
Technology
3. Crossing Over - when chromosomes
are paired so tight in Prophase 1 that
chromatids exchange info

12. Cri-du-Chat
• Loud shrieking “cry like a cat” (french)
• Chromosome 5 missing a section (mutation)
• Developmental Delays
• Microcephaly (Small Head)

13. Huntington’s
• Dominant Trait
• Mental Deterioration (Wasting Away)
• Uncontrolled Movements
• Appears in Middle Age

14. Cystic Fibrosis
Caused by recessive allele on Chromosome 7
Sufferers produce a thick, heavy mucus that
clogs their lungs and digestive passageways.
Mucus thinners
need to be taken daily

15. Phenylketonuria - PKU
• Recessive Trait
• Unable to break down phenylalanine (Aspartame) a
amino acid found in many diet foods, diet drinks, &
meats
• Consuming these items can cause irreversible
brain damage and death to a person who has PKU

16. Tay-Sachs
• Recessive Trait
• Affects mostly Jewish people
• Lipid (Fat) Buildup in Brain
• Mental Deficiency
• Blindness
• Death in early
childhood

17. Sickle Cell
Anemia
Autosomal Recessive
Genetic disorder
found mostly in
African Americans.
Characterized by the
bent and twisted
shape of the red
blood cells.

18. Down Syndrome
AKA “Trisomy 21”
Characterized by:
• Mental
Retardation
• Protruding tongue
• Thick short limbs
• Large head
• Slanted eyes
NONDISJUNCTION

19. Edwards Syndrome
AKA “Trisomy 18”
More Severe than Down Syndrome
Baby usually naturally aborted before
delivery
NONDISJUNCTION

20. Klinefelter’s
• Males with an extra X chromosome
• Male has female characteristics
• Lacks facial hair
• Sterile – can’t have any children
• Karyotype shows XXY on the 23rd
pair.
• Male because he has a Y
• NONDISJUNCTION

21. Turner’s
• Female who is missing an X
chromosome
• Puberty will not be reached, no
breast, no menstrual cycles, sterile
• Karyotype show only one X on the 23rd
pair
• NONDISJUNCTION

22. Hemophilia
• Bleeding disorder where small wounds
won’t stop bleeding.
• Swelling in joints
• Possible internal bleeding
• Patient needs many blood transfusions and
bone marrow donations
• Sex linked Recessive

23. Color Blindness
• Unable to distinguish between colors.
• Sex-linked recessive
• Mothers are usually carriers and
make their sons colorblind
• Take the test to see if you are
colorblind.
http://www.toledo-bend.com/colorblind/Ishi