NAME ______DATE ______PER_____
Chapter 9 Lesson 2: Different Ways Alleles Cooperate
Some patterns of inheritance do not follow Mendel’s laws, and are more complex. Below are some examples of these other types of inheritance.
A. ______: One allele is not completely dominant over another, therefore the heterozygous phenotype lies somewhere between the two homozygous phenotypes- A BLEND.
EX/ Japanese four o’clock plants RR = red; WW = white; RW = pink
B. ______: A gene that exists in several different forms (more than two)
C. ______: Phenotypes produced by both alleles are clearly expressed
EX/ RR = red; WW = white; RW = red and white spots
EX/ BLOOD-TYPES: ______
- For Human blood, there are _____ alleles for blood type, _____, ______, and ______
- For Human blood, ____ is codominant to the ____ allele both ____ and ____ alleles are dominant to the _____ allele
The result of the above is the possibility of 4 phenotypes:
Phenotypes / GenotypesPractice Problem #1: A type AB person is crossed with a type O person. What are the genotypic and phenotypic ratios of this cross?
Parent Genotypes: ______X ______
Square: Genotypic Ratio: Phenotypic Ratio:
Practice Problem #2: What two genotypes will produce all four phenotypes of blood?
Parent Genotypes: ______X ______
Square: Genotypic Ratio: Phenotypic Ratio:
D. ______: traits that are produced by the interaction of several genes.
Phenotype is result of the additive effects of two or more genes, produces a continuum of phenotypes.
EX/Skin color, height, IQ
Chapter 9 Lesson 3: The Importance of Sex Chromosomes
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.
EX/Hemophilia:A disorder when a person’s ______
□The X chromosome can carry either a:
- ______allele, written as ______, which codes for ______blood clotting
- ______allele, written as ______which codes for ______blood clotting (the hemophilia gene)
Female Genotypes Female Phenotypes Male Genotypes Male Phenotypes
EX/Color Blindness: A disorder where a person ______
Female Genotypes Female Phenotypes Male Genotypes Male Phenotypes
□Therefore, in order for ______to have hemophilia or color blindness, they only need ______recessive allele. (b/c they only have ______chromosome)
□Females need ______recessive alleles to show these traits (b/c they have ______chromosomes).
□Therefore, more ______tend to show sex-linked traits.
Practice Problem: 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: Cross a woman that is color blind with a man with normal vision.
Parental Genotypes: Mom : ______Dad: ______
Cross: Genotypic Ratio Phenotypic Ratio
2. PEDIGREES: Chart that shows the relationships within a family – shows the presence or absence of a trait according to the relationships between parents, siblings, and offspring.