1. Genetics

2. Inheritance Patterns Dominant / Recessive Traits Incomplete Dominance
Co-dominance
Environmentally Influenced
Multiple Alleles
Polygenic
Sex-linked
Sex-Influenced

3. Recognize a variety of intermediate patterns of inheritance (codominance and incomplete dominance).
• Interpret autosomal inheritance patterns: sickle cell anemia including the relationship to malaria (incomplete dominance), cystic fibrosis (recessive heredity), and Huntington’s disease (dominant heredity).
• Solve and interpret codominant crosses involving multiple alleles including blood typing problems. (Blood Types: A, B, AB and O and Alleles: IA, IB, and i). Students should be able to determine if parentage is possible based on blood types.
Recognize that some traits are controlled by more than one pair of genes and that this pattern of inheritance is identified by the presence of a wide range of phenotypes (skin, hair, and eye color). (polygenic)
• Understand human sex chromosomes and interpret crosses involving sex-linked traits (color-blindness and hemophilia). Students should understand why males are more likely to express a sex-linked trait.

4. GENES are more complicated than MENDEL thought
3 Patterns of DOMINANCE
Complete Dominance
Incomplete Dominance
Codominance

6. Incomplete Dominance
When an intermediate phenotype occurs and no allele dominates, incomplete dominance results.
“blending inheritance”

7. Red Flower x White Flower

8. Incomplete dominance: F1 generation
Homozygous R R W R W R W W R W R W
Homozygous

9. Incomplete dominance: F1 generation
100% pink offspring R R W R W R W W R W R W

10. Incomplete dominance: F2 generation
Heterozygous R W R R R R W W R W W W
Heterozygous

11. Incomplete Dominance F2 generation
Heterozygous
A 1:2:1 ratio with 25% red, 50% pink & 25% white offspring R W R R R R W W R W W W
Heterozygous

12. INCOMPLETE DOMINANCE DON’T SEE __________ expected _____ ratio in
F2 generation
_____________ organisms with one dominant and one recessive allele show a _________ in-between trait
3:1
Heterozygous
BLENDED
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13. RR WW RW

14. Type of Dominance?
Incomplete Dominance!

15. In radishes, the gene that controls color exhibits incomplete dominance. Pure-breeding red radishes crossed with pure-breeding white radishes make purple radishes. What are the genotypic and phenotypic ratios when you cross a purple radish with a white radish?
Parents ________ x _________
Genotype Ratio
Phenotype Ratio

16. codominance Not all alleles are dominant and recessive.
Some alleles are equally strong and neither are masked by the other.
Alleles which are equally strong are said to be "codominant“

17. codominance
When both alleles are present, they are both expressed in the phenotype.
When expressing codominant alleles, both alleles are represented by different capitalized letters.

18. A very common phenotype used in questions about codominance is roan fur in cattle.  Cattle can be red (RR = all red hairs), white (WW = all white hairs), or roan (RW = red & white hairs together).  A good example of codominance.

19. What would be the genotype and phenotype ratio if a roan cow and a roan bull were crossed?x

20. co- dominance
EX.

21. co- dominance
EX.

22. GENES are more complicated than Mendel thought
Some traits have ____________ allele __________
= ____________________
EX: blood type
Allele choices ___ ___ ___
choices
MORE than 2
MULTIPLE ALLELE TRAIT A B O

23. The pattern of sugars that is attached is determined by genes
BLOOD TYPES have more than 2 allele choices = _________________________
MULTIPLE ALLELE TRAIT
The pattern of sugars that is attached is determined by genes
Allele choices are:
_____ ____ ____ A B O

24. Multiple Alleles
Multiple Alleles – more than 2 alleles in a population for a trait, but a person can only inherit two. (one from father, one from mother)

25. Codominance: in humans
Blood Type:
A & B are equally strong.
(Co-dominant)
O is recessive.
IAi , IAIA is Type A
IBi, IBIB is Type B
IAIB is Type AB
ii is type O

26. CO-DOMINANCE
Both traits are expressed together (NO BLENDING) in heterozygote
Persons with an A allele AND a B allele have blood type AB

29. Membrane proteins with _______ attached that help cells recognize self
REMEMBER
Membrane proteins with _______ attached that help cells recognize self
= ______________
sugars
GLYCOPROTEINS

30. BLOOD TYPES An A allele tells the cell to put “A” glycoproteins
on its surface

31. BLOOD TYPES A B allele tells the cell to put a
different “B” glycoprotein
on its surface

32. BLOOD TYPES An O allele tells
the cell NOT to put anything on the surface

33. A and B are CO-DOMINANT A cell with BOTH an A and a B allele has BOTH
glycoproteins on its surface

34. A and AB see A as “like me” as Different!
DONOR BLOOD
A and AB see A as “like me”
B and O see A
as Different!
IMMUNE SYSTEM ATTACKS!
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35. B and AB see B as “like me” as Different!
DONOR BLOOD
B and AB see B as “like me”
A and O see B
as Different!
IMMUNE SYSTEM ATTACKS!
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36. O ____ can donate to EVERY BLOOD TYPE = _____________________
DONOR BLOOD O
____ can donate to EVERY BLOOD TYPE
= _____________________
Nothing on surface to
recognize as “NOT SELF”
UNIVERSAL DONOR
YOU DON’T HAVE ANYTHING I DON’T HAVE!
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37. Only AB sees AB as “like me”
DONOR BLOOD
Only AB sees AB as “like me”
A, B, and O see AB as Different!
IMMUNE SYSTEM ATTACKS!
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38. AB can only GIVE to AB BUT . . .
______ can RECEIVE FROM
EVERY BLOOD TYPE
= ________________________
UNIVERSAL RECIPIENT
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39. BLOOD TYPE FREQUENCY IN USA
40% B
10% AB 4% O
46%

40. Codominance: in humans Blood Type: phenotypic ratio 1:1:1:1
1 type A
1 type B
1 type AB
1 type O IA i IB IA IB IB i IO IA i i i

41. ABO SYSTEM is NOT THE ONLY ONE
Rh Rh-

42. OTHER BLOOD TYPES ____________________ IF: NO PROBLEMS
Rh+
MOM is _____ & BABY is ____
Rh+
MOM is _____ & BABY is _____
Rh+
Rh-
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43. Can be a ___________ IF: Mom is _____ Baby is _____
PROBLEM
Can be a ___________ IF: Mom is _____ Baby is _____
Rh+
Rh-
1st baby OK but few baby cells
entering mom’s bloodstream
put mom’s immune system on
alert for + cells.
Next + baby, mom’s immune
system can attack baby as it is
growing
Mom given shot after 1st birth prevents this
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44. Anything that can trigger this immune response is called an antigen
Anything that can trigger this immune response is called an antigen. An antigen can be a microbe such as a virus, or even a part of a microbe. Tissues or cells from another person (except an identical twin) also carry nonself markers and act as antigens. This explains why tissue transplants may be rejected.

45. What are the possible blood types of the offspring between a woman whose blood type is heterozygous A and a man who has blood type 0?

46.
Blood Typing – Remember the antibody will bond to something if it is present

47. Inheritance Patterns Dominant / Recessive Traits Incomplete Dominance
Co-dominance
Environmentally Influenced
Multiple Alleles
Polygenic
Sex-linked
Sex-Influenced

48. Polygenic Inheritance
Two or more genes involved in determining the phenotype of an organism. (wide variations)
In humans:
Height Nose length
Eye color Foot length
Intelligence
Behavior
Skin color

50. Polygenic Inheritance
-does not follow Mendel’s laws