1. Gene A unit of heredity that controls the development of one trait
Made of DNA

2. Allele Member of a paired gene Dominant alleles are expressed
One allele comes from each parent
Dominant alleles are expressed
Recessive alleles are not expressed in the presence of a dominant allele
Recessive alleles are only expressed if both recessive alleles are present

3. Examples of Alleles DD = Dwarfism Dd = Dwarfism dd = Normal height
Normal height = d
DD = Dwarfism
Dd = Dwarfism
dd = Normal height
Dwarf Band

4. Genotype Genetic make up Represented by alleles
DD & Dd are genotypes for dwarfism

5. Phenotype A trait Genotype determines the phenotype
Dwarfism is a phenotype

6. Codominant Two different alleles are both dominant
A = allele for type A blood
B = allele for type B blood
AB = results in type AB blood

7. Karyotype
Picture of chromosomes from an individual

8. Homologous Chromosomes
Chromosomes of the same pair
Karyotypes are usually arranged with homologous chromosomes paired together

9. Mutation
Change in a gene or chromosome
Causes an abnormal trait

10. Mutagen Agent that causes mutations Cigarette smoke Pesticides X-rays
Ulatraviolet light
Nuclear radiation

11. Sex Chromosomes Male have Xy Females have XX
Male gametes have either X or y
Females have XX
Female gametes have X

12. Autosomes
Chromosomes 1-22

13. X-Linked (vs Y- linked)Traits
Why are there more X-linked that Y- linked disorders?
Who suffers more frequently from sex-linked disorders? Why?

14. Which karyotype is which? A B

15. Trisomy 21: Down Syndrome
Large tongue
Flat face
Slanted eyes
Single crease across palm
Mental retardation
Some are not

16. Maternal Age & Down Syndrome

17. Trisomy 18: Edward Syndrome
Heart defects
Displaced liver
Low-set ears
Abnormal hands
Severe retardation
98% abort
Lifespan < 1 year

18. Trisomy 13: Patau Syndrome
Cleft lip and palate
Extra fingers & toes
polydactylism
Defects
Heart
Brain
Kidneys
Most abort
Live span < 1 month

19. Klinefelter Syndrome Breast development Small testes Sterile
Low intelligence
Not retarded
Klinefelter Website

20. Turner Syndrome Short Not go through puberty Produce little estrogen
Sterile
Extra skin on neck

21. Fetal Testing

22. Heterozygote Phenotype
Complete Dominance
Incomplete Dominance
CO-Dominance
Multiple Alleles
Sex-Linked Traits
Number of Alleles 2 3
Example of Alleles A a A’ B
IA IB i
XA Xa
Heterozygote Phenotype
Dominant parent
Neither parent
Both parents
Dominant OR both parents
depends
Number of genotypes 6 5
Possible Genotypes
AA, Aa, aa
AA, AA’, A’A’
AA, BB, AB
IA IA, IB IA, IA I, IB IB, IBi, ii,
XA XA, XA Xa, XaXa, XAY, XaY,
Number of phenotypes 4
Possible phenotypes
A, B
A, A’ , AA’
A, B, AB
A, B, AB, O
A, a
Classical Example
Pea plants
4 o clock flowers
Roan cows
ABO Blood group
Hemophilia
Color blindness
Example
Blue eyes X purple eyes = blue eyes
Blue eyes X purple eyes = green eyes
Blue eyes X purple eyes = blue and purple eyes
various
Males determines daughters and mother determines son

23. A man & woman are both carriers (heterozygous) for albinism
A man & woman are both carriers (heterozygous) for albinism. What is the chance their children will inherit albinism?

24. AA = Normal pigmentation
Aa = Normal pigmentation (carrier)
aa = Abino
Man = Aa
Woman = Aa A A a a

25. A a A Aa AA a Aa aa

26. AA Aa aa Genotypes Phenotypes Probability 1 AA, 2Aa, 1aa 3 Normal
1 Albino
Probability
25% for albinism

27. A man & woman are both carriers (heterozygous) for PKU disease
A man & woman are both carriers (heterozygous) for PKU disease. What is the chance their children will inherit PKU disease?

28. PP = Normal
Pp = Normal (carrier)
pp = PKU disease P p PP Pp pp P p

29. PP Pp pp Genotypes Phenotypes Probability 1 PP, 2Pp, 1pp 3 Normal
1 PKU disease
Probability
25% for PKU disease

30. A man with sickle cell anemia marries a woman who is a carrier
A man with sickle cell anemia marries a woman who is a carrier. What is the chance their children will inherit sickle cell anemia?

31. SS = Normal
Ss = Normal (carrier)
ss = Sickle Cell S s s Ss ss s

32. Genotypes ss Ss Phenotypes Probability 2 Ss, 2ss 2 Normal (carriers)
2 Sickle cell
Probability
50% for Sickle cell

33. A man with heterozygous dwarfism marries a woman who has normal height
A man with heterozygous dwarfism marries a woman who has normal height. What is the chance their children will inherit dwarfism? Dwarfism is dominant.

34. DD = Dwarf
Dd = Dwarf
dd = Normal d d D Dd dd d

35. Genotypes Dd Phenotypes dd Probability 2 Dd, 2dd 2 Normal 2 Dwarfs
50% for Dwarfism

36. XH XH = Normal Female
XH Xh = Normal Female (Carrier)
Xh Xh = Hemophilic Female
XHy = Normal Male
Xhy = Hemophiliac Male

37. A man with hemophilia marries a normal woman who is not a carrier
A man with hemophilia marries a normal woman who is not a carrier. What is the chance their children will inherit hemophilia? Hemophilia is X-linked recessive.

38. XH XH Xh XH Xh XH Xh XHy XHy Xh XH = Normal Female
XH Xh = Normal Female (Carrier)
Xh Xh = Hemophilic Female
XHy = Normal Male
Xhy = Hemophiliac Male XH XH Xh
XH Xh
XH Xh
XHy y
XHy

39. XH Xh XH Xh XHy Genotypes Phenotypes y Probability 2 XH Xh, 2XHy
2 Carrier Females
2 Normal Males
Probability
O% for Hemophilia

40. A normal man marries a normal woman who is a carrier for hemophilia
A normal man marries a normal woman who is a carrier for hemophilia. What is the chance their children will inherit hemophilia?

41. XH Xh XH XH XH XH Xh XHy Xhy Xh XH = Normal Female
XH Xh = Normal Female (Carrier)
Xh Xh = Hemophilic Female
XHy = Normal Male
Xhy = Hemophiliac Male XH Xh XH
XH XH
XH Xh
XHy
Xhy y

42. XH Xh XH XH , XH Xh, XHy, Xhy XH XH XH XH Xh XHy Xhy Genotypes
Phenotypes
2 Normal Females
1 Normal Males
1 Male Hemophiliac
XHy y
Xhy
Probability
50% for Male Hemophilic
0% for Female Hemophilic