Module 3 Unit 2: Variations in Gene Expression Flashcards
The Traits that we have learned from the previous units are considered?
qualitative traits
These traits are controlled by genes with a cumulative effect such that the phenotypes show small, gradual differences.
quantitative traits
Is an interplay between genetic makeup and environmental factors.
phenotypic variations
They are influenced by the type, number, and inheritance pattern of the gene/s.
phenotypic variations
Refers to the proportion of a population that will exhibit a particular trait if the allele is found in their genotype.
Penetrance or Quantitative Concept
100% of all individuals with the same allele in their genotype expresses the trait
Complete Penetrance
Not all individuals with the same allele in their genotype expresses the trait.
This is the type of penetrance exhibited by incomplete dominance, codominance, gene interaction, and epistasis.
Incomplete / Reduced Penetrance
Refers to the degree of expression of a penetrant gene
Expressivity / Qualitative Concept
Expressivity is dependent on?
penetrance
A trait must be __________ for expressivity to be assessed.
penetrant
Is a trait that is non- genetic
Phenocopy
Is due to an environmental factor but mimics a phenotype.
Phenocopy
These two terms refer to the expression of traits by members of monozygotic twins
Concordance and Discordance
If both monozygotic twins exhibit a trait, the trait is called?
concordant
It means that the trait has a genetic basis
Concordance
True or False:
Since monozygotic twins have exactly the same genetic composition, a genetic trait present in one member is also present in the other.
True
If a trait is exhibited by one member of a monozygotic twin but is not exhibited by the other member, the trait is?
discordant
If both members of a monozygotic twin were born deaf, then the trait most likely has a genetic basis, thus?
concordant
If only one member of the monozygotic twin is deaf, the condition cannot be genetic, thus considered?
discordant
Quantitative traits are governed by multiple genes thus referred to as?
polygenic traits
Each allele of each gene interacts ______ and contribute to the expression of that particular trait
Additively
Regions of the DNA that contribute to a quantitative trait are collectively referred to as ________ and located in different chromosomes
quantitative trait loci (QTL)
Most regions are protein-coding regions called ______, while some are __________ (thus not called genes) but still contribute to the trait
- genes
- regulatory regions
Quantitative traits are affected by both the DNA and the environment, thus called?
multifactorial
Is considerably variable because of the small continuous differences
polygenic trait
Is determined by the genes of an individual and the environment
Phenotypic Variance
Phenotypic Variance Formula
VP = VG + VE