1. Mendelian Exceptions

2. Mendel’s Principles Revisited
Inheritance of biological _____________ is determined by individual units known as ______.
During sexual reproduction, genes are passed from parents to _________.
Two or more forms of the gene for a single _____ exist, some forms of the gene may be _________ and others may be recessive.
characteristics
genes
offspring
trait
dominant

3. Mendel’s Principles Revisited
Organisms typically have ____copies of each gene, (one from each _______)
An organism’s _____ of genes (2 alleles) are segregated from each other when ________ are formed.
Alleles for different ______ usually segregate _____________ of one another. (through meiosis)
(Law of Independent Assortment)
two
parent
pair
gametes
genes
independently

4. Independent Assortment in Peas
__ Round yellow
__ Round green
__ Wrinkled yellow
__ Wrinkled green 9 3 3 1

5. Incomplete Dominance dominant traits heterozygous red pink white
In incomplete dominance, neither allele is __________ so there is a blending of ______ when two different alleles for the same trait occur together.
Colors blend together
(______________ individuals = rd phenotype)
dominant
traits
heterozygous
red
pink
white

6. Incomplete Dominance RR WW RW
In Four O’ Clocks, if you cross a red _____ (which is always pure) with a white _____ (that is also always pure) , you get a pink _____ (which is always hybrid / heterozygous RR WW RW RW RW RW RW

7. Incomplete Dominance RR BB RB
In another flower, if red ____ and blue ____ flowers are crossed, they produce a 3rd purple ____ flower
What would be the genotype ratio and phenotype ratio if you crossed two purple flowers? BB RB

8. Incomplete Dominance Cross of two purple flowers ____ X ____
What are gamete possibilities?
genotype ratio
1RR : 2RB : 1BB
phenotype ratio
1red : 2 purple : 1 blue
Can you have a heterozygous red or hybrid blue flower? ___ RB RB R B RR RB R
red
purple BB RB B
purple
blue no

9. Familial Hypercholesterolemia
FF = cholesterol about 200 mg/dL
Ff = cholesterol about 400 mg/dL
ff = cholesterol about 800 mg/dL
Ff have heart attacks in 20’s
ff have heart attacks as children
What type of inheritance is this?

10. Familial Hypercholesterolemia
F is allele for receptors in the liver that remove excess cholesterol from the blood
FF makes enough receptors removes the right amount of cholesterol
Ff only makes half the needed receptors
ff makes no receptors
This trait represents incomplete dominance

11. Problem
Tom is a 21 year old college student. His father died of a heart attack at age 25.
Tom is a vegetarian and eats no junk food. He has a fasting cholesterol of 435.
Tom’s wife, Mary, has a fasting cholesterol of 177.
They are contemplating having children
What is the chance they will have a child with abnormal cholesterol?

12. FF = 200
Ff = 400
ff = 800 F F F FF Ff f
50% chance for abnormal cholesterol

13. California Court Case
1946 the California supreme court ruled that Charlie Chaplin was the biological father of child he claimed was not his.
His defense was that the baby had type B blood. He had type A and the woman who sued him had type O (These may not be the actual blood types, but it illustrates the point)
Was the court correct?

14. O A AO OO AA, AO = Type A BB, BO = Type B AB = Type AB OO = Type O O O
The judge should take a course in genetics!

15. Codominance
alleles
Both _______ contribute to the phenotype of the organism by showing up simultaneously (at the same time) in heterozygous
individuals.
In cattle and horses, if you cross a pure ____ (RR) with a pure ______ (WW), you get (RW) which produces the color _____.
red
white
roan

16. Codominance phenotype
These cattle or horses actually have both red and white hairs intermixed, or are spotted. Roan is a third ___________.
If you cross a roan with a white…
phenotype R W RW WW W
roan
white RW WW W
roan
white

17. Codominance Andalusian chickens also show this pattern of inheritance.
If you cross a black (BB) chicken
With a white (WW) chicken
You get black+white speckled (BW) chicken

18. Multiple Alleles two two two trait
In this pattern of inheritance, the genes have more than _____ alleles controlling them and are therefore said to have multiple alleles. No individual has more than _____ alleles, but there are more than _____ possible alleles in a population, so a ______ will be expressed in more than two forms.
two
two
two
trait

19. Multiple Alleles
Blood type in humans is an example of this inheritance pattern.
The ______ different blood groups:
A, B, O, and AB
Are produced by ______ different alleles:
A, B, and O
Phenotype
Genotype A
AA or AO B
BB or BO AB
AB only O
OO only
four
three

20. Multiple Alleles
Examples of Blood type crosses

21. Multiple Alleles Blood Groups Antigen on Red Blood Cell
Safe Transfusions
Phenotype
(Blood Type
Genotype To
From

22. Multiple Alleles rabbit
The example of _______ hair color, which has at least four different alleles, is seen in these different Rex rabbits.
rabbit

23. Polygenic Traits Traits controlled by two or more genes
Show a wide range of phenotypes
The phenotype is produced by the interaction of more than ________ of genes.
1 pair

24. Polygenic Traits polygenic many eye skin
These are called ___________ traits, which means “having _______ genes”.
In humans, _____ color,
_____ color,
many
eye
skin

25. Polygenic Traits polygenic many eye skin hair
These are called ___________ traits, which means “having _______ genes”.
In humans, _____ color,
_____ color,
and _____ color
many
eye
skin
hair

26. Polygenic Traits polygenic many eye skin hair controlled
These are called ___________ traits, which means “having _______ genes”.
In humans, _____ color,
_____ color,
and _____ color
are just a few of the many traits __________ by many genes.
many
eye
skin
hair
controlled

27. James Bond Height Chart
Polygenic Traits
Sometimes the combination of the different genes results in continuous __________ of these traits.
The combined size of all the ______ parts from head to foot, determines the _______ of the person.
variation
body
height

28. Epistasis One gene affects the expression of another H allele h allele
Produces protein for A and B antigens to attach to red blood cells
h allele
Protein has wrong shape and cannot attach to A and B antigens
A and or B antigens will fall off.
hh genotype + genotype for A,B or AB blood will have type O blood
Recessive epistasis in Labrador Retrievers

29. Penetrance 100% Less than 100%
Everyone with the allele for a trait will have the trait
Less than 100%
Some individuals with the allele will not express the trait
Due to interactions of other genes

30. Incomplete Penetrance for Polydactylism
Adam
Polydactyle
Normal
Ben
Joe
Bill
Don
Bill did not express polydactylism
Frank
Mark
John
Tony

31. Expressivity Symptoms vary in intensity in different people
Due to gene interaction
Number of extra digits varies in people with polydactylism

32. Phenocopy
Trait caused by the environment that is similar to an inherited trait
Thalidomide causes symptoms of inherited phocomelia

33. Deafness May be caused by 132 different recessive genes
Man has aa for deafness on chromosome 1 & BB for normal hearing on chromosome 5
Woman has bb for deafness on chromosome 5 & AA for normal hearing on chromosome 1
What is the chance their children will inherit deafness?

34. a b Bb A Aa B AA = Normal BB = Normal Aa = normal Bb = normal
aa = deaf
BB = Normal
Bb = normal
bb = deaf a a b b Bb A Aa B A B
0% chance for deafness

35. Mitochondria Release energy from food Have their own DNA
Mitochondrial DNA
Many copies in each motochondrion
Mutate faster than nuclear DNA
Exposed to oxygen free radicals
No DNA repair enzymes

36. Mitochondria Similar to DNA of prokaryotic cells Prokaryotic cells
Engulfed into eukaryotic cells in ancient times
Have enzymes to release much more energy from food

37. Only nucleus of sperm enters oocyte
Only nucleus of sperm enters oocyte. The baby will get all mitochondia from his mother.
Mitochonria
Oocyte

38. Only inherited from mother
Mitochondrial Traits
Only inherited from mother

39. Mitochondrial DNA 37 genes
Used for metabolic reactions that release energy from food
Mitochondrial myopathies
Weak muscles
Cannot produce enough energy