1. Chapter 14
Human Genetics

2. Human Chromosomes
Karyotype = picture of chromosomes arranged in pairs & organized by size
Humans have 46 chromosomes
2 of these are sex chromosomes
             XX = female XY = male
The other 44 chromosomes are known as autosomes

4. Down Syndrome

7. NONDISJUNCTION
Failure of chromosomes to separate in meiosis – results in an egg (sperm) with too many or too few
Down Syndrome (extra #21)
Klinefelter Syndrome (XXY)
Turner Syndrome (XO)
Supermale (XYY)

8. Trisomy – 3 chromosomes Monosomy – 1 chromosome

11. 1.  A picture of a person's chromosomes is called a _____.
2.  In this pictures, chromosomes are arranged in  
pairs according to their ___________.
3.  Humans have ______ pairs of chromosomes.
4.  The last set of chromosomes is the _____ chromosomes.
5.  Males have what sex chromosomes?  ______
6.  A person who has an extra chromosome #21 has what disorder? __________
7.  If a person has XXY for sex chromosomes, he has what disorder? _________________
8.  As a woman gets _______, her risk for having a child with down syndrome increases.
9.  A human has 2 sex chromosomes, the other 44 chromosomes are called ______________.
10. When chromosomes fail to separate during meiosis,  ___________ has occurred.

12. Human Traits To study inheritance, biologists use pedigree charts
Shows relationships within a family

14. Many traits are strongly influenced by environmental factors
Not all Human Traits can be traced back to a single gene
Many traits are strongly influenced by environmental factors
(ex: height, weight, personality)

15. Human Genome Our complete set of genetic info
Includes thousands of genes
Base sequences of many genes identified

16. BLOOD TYPES
Genes controlling blood types were 1st genes to be identified
ABO & Rh blood groups ( + and - )

17. ABO Blood GroupMultiple Allele Trait
Controlled by 3 alleles:  A, B, O
A and B are codominant
O is recessive to both A and B
The blood type is the phenotype

18. (universal recipient)
Genotype
Blood Type
AA, AO
Type A
BB, BO
Type B
AB codominant
Type AB
(universal recipient)
OO recessive
Type O (universal donor)

19. Blood Types Practice
Mom has type A blood (genotype AO), dad has type AB blood. What blood types are possible among their children?
Mom has type B blood (genotype BO), dad has type O blood. What blood types are possible among their children?

20. Human Genetic Disorders
Phenylketonuria (PKU)
Tay – Sachs disease
Albinism                          * all recessive

21. Other animals can be albino too..

22. Sickle-Cell Disease codominant (AA, Aa, aa )
heterozygous is resistant to malaria

23. Achondroplasia (dwarfism)
Huntington’s disease
* Both dominant

24. 1.  Achondroplasia is another name for ____________
2.  What are the four possible blood types? _______
3.  Is albinism dominant or recessive? _________
4.  If two people are both heterozygous for sickle cell trait, what is the chance they they will have a child with sickle cell disease?
5.  If a person with type A blood is married to person with type O blood, what blood types are possible in their children?
6.  The human _______ describes all the genes found in humans.
7.  What type of chart is used to study a trait in a family? __