1. Beyond Mendelian Inheritance

2. INCOMPLETE DOMINANCE NEITHER ALLELE IS COMPLETELY DOMINANT
OVER THE OTHER
THE HETEROZYGOUS PHENOTYPE IS
A BLENDING OF THE TWO
HOMOZYGOUS PHENOTYPES
Red flower = RR
Pink flower = Rr
White flower = rr

3. A trait exhibits incomplete dominance is the pitch of human male voices:
-Lowest pitch (LL) and highest pitch (ll), but the intermediate range baritones are (Ll)
Guess the genotypes:
______ ______

4. Sample problem:
Red snapdragon flowers (R) are incompletely dominant to white snapdragon flowers (r).
A heterozygous flower is crossed with a white flower.
What is the genotypic and phenotypic ratios of the offspring?

5. CODOMINANCE
-BOTH THE DOMINANT ALLELES ARE EXPRESSED IN THE HETEROZYGOUS INDIVIDUAL.
-USE 2 DIFFERENT CAPITAL LETTERS TO RERESENT THE DOMINANT ALLELES

6. Cattle:
A homozygous red bull and a homozygous white cow will produce a heterozygous roan (spotted) offspring
Red cow ______
White cow ______
Roan cow ______

7. Sample problem:
Red and white coat color are co-dominant in cattle. Two heterozygous cows are crossed. What is the genotypic and phenotypic ratio of the offspring?

8. MULTIPLE ALLELES
Several dominant alleles and/or recessive alleles can be combined to create multiple phenotypes.

9. Blood Type
In human blood, type A blood and type B blood are codominant. However, there is a recessive allele for type O.
Type A and B show regular dominance over this recessive allele. Thus, the only way to be type O is to be homozygous recessive.

10. BLOOD TYPE
CAN RECEIVE FROM:
CAN DONATE TO:
Type A
Type B
Type AB
Type O

11. Sample Problem #1: Adam Sandler is homozygous for type A blood
Sample Problem #1: Adam Sandler is homozygous for type A blood. Megan Fox is heterozygous for type B. If they have kids what will be the genotypic and phenotypic ratios of the possible kids?

12. Human Blood Genotypes and Phenotypes
Phenotype Genotype(s) 1. 2. 3. 4.

13. Sample Problem #2: Jimmy Fallon has type O blood
Sample Problem #2: Jimmy Fallon has type O blood. Jennifer Aniston has type AB blood. If they have kids what will be the genotypic and phenotypic ratios of the possible kids?

14. Sample Problem #3: Channing Tatum has type A blood. Ms
Sample Problem #3: Channing Tatum has type A blood. Ms. Palmeri has type B blood. They have a baby with type O blood. How is this possible? Show your work!

15. Polygenic Traits
Most of your traits are controlled by the interaction of many genes.
Multiple genes working together produce a continuous distribution in a “Bell Shape” curve of degrees.

16. Examples of Polygenic Traits
Body Type
Height
Skin Color
Hair color
Eye color
Intelligence
We often see the famous “Bell Curve”
Individual genes of a polygenic trait follow Mendel's laws but together do not produce Mendelian ratios.

19. The Environment Heavily Influences Polygenic traits

20. …..have some genetic link but also environmental explanation.
Recent studies show …
Hypertension
Diabetes
Cancers
Allergies
Cardiovascular diseases
Behavioral traits (alcoholism and phobias)
…..have some genetic link but also environmental explanation.

21. Autosomal Dominant, Autosomal Recessive, and Sex-Linked
Genetic Diseases
Autosomal Dominant, Autosomal Recessive, and Sex-Linked

22. Autosomes = first 22 pairs ofchromosomes Sex Chromosomes = 23rd pair of chromosmes (X and Y)

23. Autosomal Dominant
Autosomal dominant is one of several ways that a trait or disorder can be passed down through families.
Caused by the presence of a dominant allele.
If a disease is autosomal dominant, it means you only need to get the abnormal gene from one parent in order for you to inherit the disease. One of the parents may often have the disease.

24. Huntington’s Disease
a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems
It typically becomes noticeable in mid-adult life.
HD is the most common genetic cause of abnormal involuntary writhing movements
HH or Hh = Huntington’s disease
hh= normal

25. Neurofibromatosis NN or Nn = Neurofibromatosis nn= normal
a genetic disorder characterized by a number of remarkable skin findings including multiple cafe au lait (coffee with milk) spots, multiple benign tumors on the skin, thick and misshapen nerves, and freckles in the armpit and groin.
The cafe au lait spots increase in number and size with age.
increased risk of scoliosis, optic gliomas (benign tumors on the optic nerve), epilepsy, and learning disability
inherited in an autosomal dominant manner and is due to mutation of the NF1 gene (in chromosome band 17q11) that encodes a protein called neurofibromin.
Half of cases are due to new mutations in the NF1 gene. Prenatal testing is available. Also called von Recklinghausen disease.
NN or Nn = Neurofibromatosis
nn= normal

26. Autosomal Recessive Caused by inheriting 2 recessive alleles.
An autosomal recessive disorder means two copies of an abnormal gene must be present in order for the disease or trait to develop (aa).
A person who is heterozygous (Aa) is considered a “carrier” of the gene.

27. Albinism
a defect of melanin production that results in little or no color (pigment) in the skin, hair, and eyes.
AA = normal
Aa = carrier
aa = albino

28. Tay-Sach’s Disease Deadly disease of the nervous system
body lacks a protein that helps break down a chemical found in nerve tissue
Without this protein, the chemical build up in cells, especially nerve cells in the brain.
Symptoms appear at 3-6 months old
Death in early childhood 3-5 years old
Common among the Ashkenazi Jewish population
About 1 in every 27 members of the Ashkenazi Jewish population carries the Tay-Sachs gene
TT= normal
Tt= carrier
tt= Tay Sach’s

29. Cystic Fibrosis
Causes thick, sticky mucus to build up in the lungs, digestive tract, and other areas of the body.
It is one of the most common chronic lung diseases in children and young adults.
An estimated 1 in 29 Caucasian Americans have the CF gene.
The disease is the most common, deadly, inherited disorder affecting Caucasians in the United States. It's more common among those of Northern or Central European descent.
Most children with CF are diagnosed by age 2.
A small number, however, are not diagnosed until age 18 or older. These patients usually have a milder form of the disease and live until their mid- 30’s.
CC= normal
Cc= carrier
cc= cystic fibrosis

30. Sample Problem #1. Albinism is a recessive disorder. Mr
Sample Problem #1.Albinism is a recessive disorder. Mr. Ward is and his wife are both heterozygous, making them carriers of the albinism gene. What’s the chance their next child will be albino?
50%
25% 0%
75%

31. Sample Problem #2. Tay Sach’s is a recessive disorder
Sample Problem #2. Tay Sach’s is a recessive disorder. A normal person marries a carrier of Tay Sach’s disease. What is the percent chance of them having a child that is a carrier? 0%
25%
50%
75%

32. Huntington’s disease is autosomal dominant
Huntington’s disease is autosomal dominant. Olivia Wilde has Huntington’s disease. What is her genotype? HH Hh
HH or Hh

33. Sex-Linked Inheritance
Follows Mendel’s principle of dominance however the genes that are located on the X chromosome
Sex chromosomes (X and Y)
Female = XX Male = XY
XH = dominant allele
Xh = recessive allele
Because the allele is located on the X chromosome, sex-linked genetic disorders are more common in males!

34. Sex-Linked Recessive Disorders
Hemophilia
Duchenne’s Muscular Dystrophy
Red-Green Colorblindness
Male Pattern Baldness

35. Sex-Linked Example Hemophilia (Xh)is a sex linked recessive disorder.
Female Genotypes
Phenotype 1. 2. 3.
Male Genotypes
Phenotype 1. 2.

36. Sample Problem #1
Hemophilia is a sex-linked recessive condition. Beyonce is a carrier of hemophilia and Jay-Z is normal. What are the chances of them having a child with hemophilia?

37. Sex Linked Formative
Jimmy Fallon is colorblind and Tina Fey is a carrier. What are the chances of them having a color blind child? Circle the color blind children. Xb Y
XbY
XBXb XB
XbXb
XBY
XBXb , XbXb , XBY , XbY
50% Chance of colorblindness
1 Colorblind : 1 Normal Vision
Genotypes
Phenotypes X

38. Sample Problem #3
Will Smith is normal for male-pattern baldness, but Jada Pinkett Smith is a carrier. What are the chances of their daughter, Willow, being a carrier? Is it possible for their son, Jaden, to have inherited male pattern baldness?

39. Sex-Linked Dominant Disorders
Fragile X Syndrome
Rett Syndrome
Charcot–Marie–Tooth disease
Vitamin D resistance Rickets