Download GENETICS NOTES PART II – OTHER TYPES OF INHERITANCE

GENETICS NOTES PART II – OTHER TYPES OF INHERITANCE
Some patterns of inheritance do not follow Mendel’s laws, and are more complex. Below are some
examples of these other types of inheritance.
Multiple Alleles = _______________________________________________________________
o
For Human blood, there are ______ alleles for blood type _____, _____, and _____
Codominance = _________________________________________________________________
o Example #1: For Human blood, ______ is codominant to the ______ allele,
and both ______ and ______ alleles are dominant to the ______ allele
The result of the above is the possibility of 4 phenotypes:
Phenotypes
o
Genotypes
Example #2: Cattle hair color
When both the red allele and white allele are present – both red and white hairs will be
seen.
Phenotype
Red
Roan
White
Genotype
Incomplete Dominance = _________________________________________________________
o Example: Snap Dragons (flowers)
o Red flower x White flower = all pink flowers!!!!!
RR =
RW =
WW =
Practice Problem #1: A type AB person is crossed with a type O person. What are the genotypic and
phenotypic ratios of this cross?
Type of Inheritance Pattern: _____________________________________________
Parent Genotypes: ___________ X __________
Square:
Genotypic Ratio:
Phenotypic Ratio:
Practice Problem #2: What two genotypes will produce all four phenotypes of blood?
Type of Inheritance Pattern: _____________________________________________
Parent Genotypes: ____________ X ______________
Square:
Genotypic Ratio:
Phenotypic Ratio:
Practice Problem #3: A white cow is crossed with a roan cow. What are the possible genotypic and
phenotypic ratios?
Type of Inheritance Pattern: _____________________________________________
Parent Genotypes: ___________ X __________
Square:
Genotypic Ratio:
Phenotypic Ratio:
Practice Problem #4: If roan cow is crossed with a roan cow, what are the possible genotypic and
phenotypic ratios?
Type of Inheritance Pattern: _____________________________________________
Parent Genotypes: ___________ X __________
Square:
Genotypic Ratio:
Phenotypic Ratio:
Practice Problem #5: A pink flower is crossed with a pink flower. What are the possible genotypic
and phenotypic ratios?
Type of Inheritance Pattern: _____________________________________________
Parent Genotypes: ___________ X __________
Square:
Genotypic Ratio:
Phenotypic Ratio:
Practice Problem #6: If pink is crossed with a white flower, what are the possible genotypic and
phenotypic ratios?
Type of Inheritance Pattern: _____________________________________________
Parent Genotypes: ___________ X __________
Square:
Genotypic Ratio:
Phenotypic Ratio:
II. SEX-LINKED GENES: ________________________________________________________
 In humans, the 23rd pair of chromosomes are called the ________________________________
 Females are ___________ and males are __________ for this pair.
 If we cross a male and a female:
Genotypic Ratio
Phenotypic Ratio
 Therefore, the _________ determines the sex of the child.
 Some _________ are carried on the _______ chromosome. When writing genotypes they are
written as ___________________.
 Two examples of genes carried on the X chromosome are ______________ & _______________
 Because they are carried on the X chromosome, they are called ____________________ traits.
Hemophilia: A disorder when a persons _________________________________________
The X chromosome can carry a ___________allele, written as ________, which codes
for __________ blood clotting or a ___________ allele, written as _________ which
codes for __________ blood clotting (the hemophilia gene)
Female Genotypes
Female Phenotypes
Male Genotypes
Male Phenotypes
Color Blindness: A disorder where a person ______________________________________
Female Genotypes
Female Phenotypes
Male Genotypes
Male Phenotypes
o
As you can see from the above phenotypes and genotypes, in order for ___________ to have
hemophilia or color blindness, they only need ________ recessive allele.
(b/c they only have _____ ______ chromosome)
o
Females need ______ recessive alleles to show these traits
(b/c they have ____ ____ chromosomes).
Therefore, more _________ tend to show sex-linked traits.
o
Practice Problem #7: Cross a woman that is a carrier (heterozygous) for hemophilia with a male
hemophiliac.
Parental Genotypes: Mom : _________ Dad: _________
Cross:
Genotypic Ratio
Phenotypic Ratio
Practice Problem #8: Cross a woman that is color blind with a man with normal vision.
Parental Genotypes: Mom : ________ Dad: _________
Cross:
Genotypic Ratio
Phenotypic Ratio