Chapter 5 Flashcards
What is phylogenetic inheritance ?
More than 1 gene may control 1 characteristic.
What are polyploid genes?
1 gene may hv many alleles sometimes resulting in different phenotypes.
What are pleiotropic genes?
1 gene controls more than one genotype
What is haplosufficiency?
1 single gene is enough for the trait to be presented.
That’s why the dominant trait heterozygous are presented.
What are the cases where the mutant allele is dominant over the wild type allele?
Haploinsufficiency.
Spoiler allele.
Neomorphic alleles (mutation).
What are the cases where no allele is dominant or recessive?
Incomplete dominance.
Co-dominance.
Explain Incomplete dominance.
When red snapdragons are crossed with white ones. The offspring are pink and not white or red in the F1 generation. Meaning there is no dominant allele.
In F2 it’s a a ratio of white: pink: red…. 1:2:1
A test cross has ratio of 1:1…. white/red: pink.
A way to identify is heterozygous offspring will hv a different genotype than parents.
Explain Co-dominance.
Heterozygous individual has phenotype of both homozygous parents….like in blood grps.
Explain Co-dominance in blood grouping.
What are lethal alleles?
Mutation in essential gene causes death.
What are conditional alleles?
Phenotypes expresses order particular conditions.
Conditions where they are expressed are permissive.
Conditions where they are not expressed are restrictive.
Examples of conditional alleles
What is phenotype penetrance?
%of individuals w/a genotype who show the phenotype of said genotype.
What is phenotype expressivity?
The extent to which a phenotype is expressed in an individual.
Example of phenotype expressivity.
Polydactyly ….
