1. MONOHYBRID CROSSES.
Among dogs wire hair is a dominant over smooth. If a heterozygous wire haired male is crossed with a homozygous smooth haired female, what would be the genotypes of their puppies?
ln rabbits short ears are dominant over long ears. What would the phenotypes be if two heterozygous short eared rabbits were mated?
Among guinea pigs black hair is dominant over white. What would be the phenotype of the guinea pigs if a homozygous white male was mated with a homozygous white female?

2. 4. In humans brown eyes are dominant over blue eyes
4. In humans brown eyes are dominant over blue eyes. If a heterozygous brown eyed male marries a heterozygous brown eyed female, what would be the phenotypes of the children?
5. Among tulips yellow color is dominant over blue. If a heterozygous yellow tulip is crossed with a homozygous blue, what would be the phenotypes and genotypes of the tulips?
6. Among squash smooth seeds are dominant over wrinkled seeds. If two heterozygous smooth squash plants are crossed, what would be the phenotypes and genotypes of the seeds?

3. PATTERNS OF INHERITANCE AND HUMAN GENETICS

4. SIMPLE RECESSIVE INHERITANCE
CYSTIC FIBROSIS:CF
Common in white Americans 1:2000
Caused by defective protein in plasma membrane.

5. CYSTIC FIBROSIS:CF
3. Controlled by physical therapy, diet, drug therapy 4. Life expectancy improving annually 5. Person must have 2 recessive alleles to suffer from CF. 1 allele carrier but shows no symptoms

7. PHENYLKETOURIA (PKU) Phenylketouria:
1. Caused by the absence of an enzyme that converts the amino acid phenylalanine to tyrosine.
2. Accumulation of phenylalanine leads to mental retardation and CNS damage

8. PHENYLKETOURIA (PKU)
3. Newborns are given a blood test to check for the absence of the enzyme 4. Milk products are high in phenylalanine 5. Disorder is treatable by controlling diet from birth

10. OTHER RECESSIVE TRAITS
TAY-SACHS
ATTACHED EAR LOBES

11. SIMPLE DOMINANT TRAITS
HUNTINGTON’S DISEASE:
Lethal disorder, no treatment
Certain areas of the brain breakdown
Symptoms; neurological and muscular show at the age of 30+
Genetic testing is available before symptoms show

12. HUNTINGTON’S DISEASE:
5. Ethical issues
6. Every child of an affected person has a /50 chance of inheriting the disease
7. Only 1 defective allelle required for person to show disease

13. OTHER DOMINANT TRAITS Unattached ear lobes Tongue rolling Hapsburg lip
Hitchhiker’s thumb
Hairy fingers
Almond shaped eyes
Thick lips
Widow’s peak

15. INCOMPLETE DOMINANCE

16. INCOMPLETE DOMINANCE
Heterozygous phenotype is intermediate between those of the two homozygotes
Red flower x white flower
Intermediate phenotype is pink F1 F2 R’ R’ R R’ R R
R’R
R’R RR
R’R R R’
R’R
R’R
R’R
R’R’

17. CODOMINANCE
CODOMINANT ALLELES CAUSE THE PHENOTYPE OF BOTH HOMOZYGOTES TO BE PRODUCED IN THE HETEROZYGOTE INDIVIDUALS. BOTH ALLELES ARE EXPRESSED EQUALLY
B = black feathers in chickens
W = white feathers in chickens
BB = black chicken
BW = checkered chicken
WW = white chicken B W BB BW B BW WW W

18. CODOMINANT TRAITS SICKLE-CELL ANEMIA:
Common among African Americans 1:12
Homozygous people for trait differ by 1 amino acid coding for hemoglobin compared to normal people

19. SICKLE-CELL ANEMIA: 3. Abnormal hemoglobin is sickle celled
4. Sickle shaped cells block blood vessels reducing the amount of oxygen reaching the tissues 5. Shortened life span

21. HETEROZYGOUS ADVANTAGE
People who are heterozygote for the trait produce both normal and abnormal hemoglobin
Show no symptoms of sickle- cell anemia
Less likely to suffer from malaria
This explains why African’s suffer more from sickle-cell anemia

22. MULTIPLE PHENOTYPES FROM MULTIPLE ALLELES
Traits controlled by more than two alleles have multiple alleles

23. POLYGENTIC INHERITANCE
A trait is controlled by two or more genes.
Inheritance of eye color, height, stem length, skin color.

25. BLOOD GROUPS ABO blood group
Single gene (represented as “I”) has 3 different alleles
Blood type A genotype IA IA IA i
Blood type B genotype IB IB IB i
Blood type AB genotype IA IB (codominant)
Blood type O genotype ii (recessive)
Important in blood transfusions and paternity suits

26. SEX DETERMINATION Autosomes 22 pairs of homologous chromosomes
23rd pair of chromosomes are sex chromosomes X and Y
Female XX chromosomes
Male XY chromosomes

27. Gametes carry either an X or Y chromosome
Fertilization results in offspring having either XX or XY chromosomes
There is a 50:50 chance of producing a male or female each time an offspring is produced.

28. SEX-LINKED INHERITANCE
Experiments conducted by Morgan
Observed males had white eyes more often than females
Suggested gene for eye color was carried on the X chromosome and Y chromosome has no corresponding gene for eye color

29. INHERITANCE OF EYE COLOR IN DROSOPHILA

31. COLOR BLINDNESS X-linked disorder
Inability to differentiate between two colors such as red and green
Males are more susceptible because they have to inherit 1 defective X chromosome to suffer from the disorder; females needed to inherit 2 defective chromosomes.
Most serious problem is the inability to detect traffic light colors

33. HEMOPHILIA X-linked disorder
Caused by a lack of factor VIII a blood clotting enzyme
Inability to clot the blood

35. Males are more susceptible because they have to inherit 1 defective X chromosome to suffer from the disorder; females needed to inherit 2 defective chromosomes.
Treated by blood transfusions and injections of factor VIII.
Treatments are expensive and some people have contracted AIDS.

36. WHO IS RYAN WHITE???

37. CHANGES IN CHROMOSOME NUMBERS
Nondisjunction: paired chromosomes fail to separate properly during meiosis
TRISOMY: person has 47 chromosomes total
Down’s syndrome: chromosome 21 3 copies inside of 2. Mental retardation etc, higher incidence in women over 40.

39. Klinfelter’s syndrome: males, extra X or Y chromosome.
MONOSOMY: 45 chromosomes
Turner’s syndrome: females, missing X chromosome, mental retardation, sterile.

40. KARYOTYPE
Chart of chromosome pairs used to evaluate unusual chromosome numbers in cells.
Amniocentesis is the procedure by which the cell are collected for analysis and production of the karyotype.