Module 3 Flashcards
What are intra allelic effects?
The effect of an allele on a protein
What are inter allelic effects?
The affect of other genes influencing it
What is gene action?
From genotype to phenotype
What is the agouti gene?
Encodes to signal peptide for colour and lipid metabolism
Lethal gene example
The agouti gene
Are mutations of haplosufficient genes recessive or dominant?
Recessive
What is an allelic series?
Most common allele for a locus in nature arbitrarily referred to as wild-type, often dominant
If an allele is not wild-type, what is it considered?
Considered a mutant
What does an allelic series describe?
Dominance hierarchy of multiple alleles
What is the function of a null allele?
It does not have a function
What is hypomorphic allele function?
It has a partial function
What is incomplete dominance?
Appearance of third phenotype that blends two parental ones, no clear dominance in heterozygote, blending
What is codominance?
More than one allele is dominant, heterozygote displays both parental phenotypes, shows both
What kind of relationships are codominance and incomplete dominance?
Non- Mendelian relationships
Incomplete dominance example in humans
Skin pigmentation
Codominance example in humans
ABO blood type
What kind of gene causes blood type in humans?
I gene
What is variable/incomplete penetrance?
The proportion of individuals of the same genotype that will either express determined phenotype or not express it at all, only some percentage of people show the trait
Example of variable penetrance in humans
Retinoblastoma and polydactylyl
What is variable expressivity?
Degree or intensity with which a genotype is expressed, all show the consequences but not to full extent just to a degree of severity
Examples of variable expressivity in humans
Marfan syndrome
Is it possible to have both variable penetrance and variable expressivity?
Yes
What is an example of variable penetrance and variable expressivity in humans?
Neurofibromatosis
What is pleiotropy?
One allele, affecting two or more phenotypes
What is polygenic inheritance?
Many genes and alleles, affecting the same phenotype
What are some qualitative phenotypes?
Height, skin colour, weight, intelligence, behavioural phenotypes
What are complementation tests?
Based on that wild-type alleles will make up for mutated ones of a given gene
What is allelism?
When mutations are alleles of same gene