1. Other patterns of inheritance.

2. I. Beyond Dominant and Recessive Alleles

3. A. Incomplete dominance – neither allele is dominant or recessive
Use two different letters for genotypes
heterozygous condition = blended phenotype
Examples:
a. Red Snapdragon x White Snapdragon = Pink Snapdragon

4. Incomplete dominance
The condition that arises when neither allele controlling a characteristic is dominant 
Mixture of the traits

5. Aa – normal blood with some sickle cells
Sickle Cell Anemia
a single DNA base change causes an incorrect amino acid
RBC in shape of a sickle
low O2
blood clots/damaged organs
carriers resistant to malaria
AA – normal blood
aa – sickle cell
Aa – normal blood with some sickle cells
Incomplete Dominance

6. b. Oompah Loompas can have red, blue or purple hair.
Alleles: RR =
BB =
RB = P:
F1 geno:
F1 pheno:
Probability:

7. B. Codominance both alleles are dominant
use capital of same letter with a prime (R’)
heterozygous condition = both phenotypes “show”
Examples:
a. Horses with both brown and white hairs
R= Brown hair
R’= White hair

8. CoDominance
Alleles of a gene pair in a heterozygote are fully expressed, you see both phenotypes.

9. Codominant vs incomplete

10. b. Orange and white fish are codominant.
Alleles: P:
F1 Geno:
F1 Pheno:
Probability:

11. C. Multiple Alleles
Many genes have several (more than 2) different forms
Examples:
Rabbit Coat Color – one gene gives 4 alleles, thus 4 phenotypes
Human Blood Groups – one gene gives 3 alleles and 4 phenotypes

12. The gene for blood type has 3 possible alleles.
Multiple Alleles/Co-Dominance
In traits with multiple alleles, each individual can carry any two of the several possible alleles.
Ex. BLOOD TYPE
The gene for blood type has 3 possible alleles.
A B O

13. i. ABO Blood Group 3 alleles: IA, IB, i
Alleles IA and IB are codominant
Allele ‘i’ is recessive
Phenotype
(Blood Type)
Safe Transfusions
Genotype
Antigen on
Red Blood Cell To
From

14. ABO blood groups: based on the presence of two major protein antigens:
Antigens: molecules on the surface of RBC’s that stimulates cells to produce antibodies.
Antibodies: protein that cells of the immune system produce in response to the presence of a nonself antigen
ABO blood groups: based on the presence of two major protein antigens:
A and B

15. Current Blood types

16. ii. Rh Blood Groups 2 alleles: Rh+ and Rh- positive and negative
Rh+ = dominant
Rh- = recessive
Follows simple dominance rules

17. iii. Examples
What blood types would expect the children to have if their parents are type A and type B with genotypes of IAi and IBi?
If this couple is heterozygous for Rh+ blood, could they have a child Rh- blood?

18. D. Polygenic Our most common traits are polygenic
examples:
hair color (2 genes)
eye color (16 genes)
height (50 genes)
skin color (100 genes)
The more genes for one trait allows for more variation (differences) of phenotypes

19. AABBCC = darkest level of pigmentation
Skin color is controlled by three genes that interact additively to influence the amount of melanin produced by cells.
The more melanin that is produced, the darker the pigmentation of the skin.
It is also called quantitative inheritance, because each gene “adds” to the amount of melanin.
AABBCC = darkest level of pigmentation
aabbcc = lightest level of pigmentation
3. What color skin would a person with AaBbCc genotype have?

20. If skin color is controlled by 3 genes, these are the possible phenotypes.
4. Examine the genotypes shown, there is a pattern that explains why polygenes are also called “ADDITIVE.” What is the pattern?
AABBCC =
AaBBCC AABbCC AABBCc
AAbbCC AABBcc
AABbCc AaBBCc
Dark brown
Medium browns
Light browns
Count the number of dominant letters, the more you have, the darker the pigment.
Dark tans

21. More phenotypes... AABBCC AaBBCC AABbCC AABBCc AAbbCC AABBcc
Dark brown
AAbbcc aaBBcc aabbCC aaBbCc AaBbcc AabbCc
Aabbcc aaBbcc aabbCc
aabbcc Pale (albino)
Light tans
Medium browns
Light browns
Fair
Dark tans
5. What genotypes would you assign to Jonah and Sophia?
Medium tans

22. Skin color

24. Colorblind Female: XaXa
Sex-Linked Traits: is a trait in which a gene is located on a sex chromosome
Women have two X chromosomes. Therefore, women have two copies of information - one on each homologous chromosome – just like with autosomes.
Normal Female: XAXA
Carrier Female: XAXa
Colorblind Female: XaXa
Note: A carrier is not affected by a trait, but can pass it on to her offspring
Normal Male: XAY
Colorblind Male: XaY

25. SEX-LINKED INHERITANCE
Traits controlled by genes located on sex chromosomes.
XAXa x XAY

26. Cross a male that has hemophilia with a female that is homozygous dominant for normal blood.

27. Are you colorblind?

28.  Normal Vision
Color Blind 

31. II. Genes & Environment
Phenotypes are only partly determined by genotypes (alleles) given to offspring by parents
The environment can change/alter the genes that code for the expected phenotype
An individuals actual phenotype is determined by its environment and inheritance
Examples:
Fruit Flies - # bristles changes with temperature
Plants – altitude changes height
Humans with PKU – change diet to avoid chemical, no longer have disorder