Dominance Lect.
1/29/24
Chi- square statistic used to quantify data and determine whether or not a sample is following simple Mendelian inheritance patterns. (P< 0.05, we reject the null hypothesis (simple mendelian) ; P>0.05 not significant, we accept null hypothesis)
The P value is the probability of observing your result or something at least as extreme given that your expectation (null model) is correct
Degrees of Freedom- equal to the number of independent variables in an experiment, it will typically be the number of phenotypic classes (n) minus 1.
Genes are regions of DNA that encode a function product- typically a protein
Alleles are versions of a gene that have differences in the code resulting in different forms if the protein; Alleles can have functional effects due to different protein shapes (full, partial, or no function) or different amounts
Types of Alleles
Null- An allele that produces no functional product
Hypomorphic- an allele with function similar to but less than the wild-type allele. Some product may be produced or a small amount of function maintained despite a change in shape
Dominant negative- an abnormal product produced by one allele interferes with the overall function of the protein, even if the other is functional
Hypermorphic- an allele that results in too much expression of the product- leading to a deleterious effect
Neomorphic- the allele changes the function to something different from the wild type
The type of dominance depends in the specific pair of alleles and what happens when two different versions of the same gene are present in the heterozygote
Types of Proteins
Enzymes are proteins that catalyze a specific biochemical reaction
Example: Snapdragon Colors
In snapdragons, the ANS gene codes for color→ An1 and An2 are two different versions (alleles) of the ANS gene that determines the phenotype of
the flower color trait.
The allele that when homozygous results in the white phenotype is actually a loss of function null allele that results in a completely inactive enzyme.
Incomplete Dominance: ON
Hypomorphic alleles produces less function proteins and are typically recessive.
1/29/24
Chi- square statistic used to quantify data and determine whether or not a sample is following simple Mendelian inheritance patterns. (P< 0.05, we reject the null hypothesis (simple mendelian) ; P>0.05 not significant, we accept null hypothesis)
The P value is the probability of observing your result or something at least as extreme given that your expectation (null model) is correct
Degrees of Freedom- equal to the number of independent variables in an experiment, it will typically be the number of phenotypic classes (n) minus 1.
Genes are regions of DNA that encode a function product- typically a protein
Alleles are versions of a gene that have differences in the code resulting in different forms if the protein; Alleles can have functional effects due to different protein shapes (full, partial, or no function) or different amounts
Types of Alleles
Null- An allele that produces no functional product
Hypomorphic- an allele with function similar to but less than the wild-type allele. Some product may be produced or a small amount of function maintained despite a change in shape
Dominant negative- an abnormal product produced by one allele interferes with the overall function of the protein, even if the other is functional
Hypermorphic- an allele that results in too much expression of the product- leading to a deleterious effect
Neomorphic- the allele changes the function to something different from the wild type
The type of dominance depends in the specific pair of alleles and what happens when two different versions of the same gene are present in the heterozygote
Types of Proteins
Enzymes are proteins that catalyze a specific biochemical reaction
Example: Snapdragon Colors
In snapdragons, the ANS gene codes for color→ An1 and An2 are two different versions (alleles) of the ANS gene that determines the phenotype of
the flower color trait.
The allele that when homozygous results in the white phenotype is actually a loss of function null allele that results in a completely inactive enzyme.
Incomplete Dominance: ON
Hypomorphic alleles produces less function proteins and are typically recessive.
