Complexities Relating Genotype to Phenotype Flashcards
What is wild type allele?
Functional protein
What is mutant allele?
Often non-functional or unstable protein
Where can you find wild type and mutant allele?
In diploids
Finish the sentence:
Many wild type alleles are…
Dominant
Finish the sentence:
Many mutant type alleles are…
recessive
What is a problem that can occur with dominant alleles?
They aren’t always complete
Define incomplete dominance:
heterozygotes show an intermediate phenotypes
Give an example of incomplete dominance:
red and white flowers can produce pink flowers
Define co-dominance:
heterzogyotes show phenotype of both allels
Give an example of co-dominance
Blood
Define multiple alleles:
More than two alleles for a gene
What do multiple allele establish?
Dominance hierarchy
Define pleiotropy:
One gene contributes to more than one trait
Give an example of pleiotropy:
Genes involved in cilia and flagella
Define lethal alleles:
Gene which if contains both of lethal gene will produce not be born
What is the problem with lethal alleles?
Cause skewed phenotypic ratios
What is sickle-cell syndrome an example of?
Dominance and pleiotropy
Is sickle-cell physiological levels co-dominance or incomplete dominance?
incomplete dominance
Is sickle-cell biochemical levels co-dominance or incomplete dominance?
co-dominace
What can gene combinations rise?
Novel phenotypes
How many major genes at least determine coat colour in mammals?
5
Define epistasis:
A gene interaction in which the effects of an allele at one gene hide the effects of alleles at another gene
What can complementation tests determine?
Determine if a phenotype arises from mutations in the same or separate genes
What does penetrance measure?
The percentage of individuals with a given genotype who exhibit the phenotype associated with the genotype
What does expressivity measure?
Extent to which given genotype is expressed at the phenotypic level
Main interactions between alleles of a gene:
- Dominance
- Incomplete dominance
- Co-dominance
- Pleitropy
- Lethal alleles
Main interactions between genes:
- Gene combinations
- Epistasis
- Genetic complementation tests
