Genetics
a genetic phenomenon where one or more genes modify the expression of another gene
epistasis
Genetic drift is a powerful mechanism of evolution, especially in _____ populations
small
common phenotypes are selected against, and rare phenotypes are favored
Negative frequency-dependent selection
What does q represent in HWE?
frequency of the recessive allele
where does transcription occur?
nucleus
What does VE represent in the phenotypic variation equation?
variance due to environmental differences
a type of bottleneck resulting from a small number of individuals colonizing a new, isolated habitat
founder effect
homozygous condition yields twice the phenotypic effect for the gene as compared with heterozygotes
additive alleles
what does p2 represent in HWE?
frequency of the homozygous dominant genotype
number of copies of unique chromosomes in a cell
ploidy
The depth of root growth in response to soil moisture is an example of ________ _________.
phenotypic plasticity
an allele that is the only variant present for a specific gene within a population
fixed allele
How does high inbreeding within a population affect infant survival rates?
lowers them
If a population is in HWE, then how will the ratios of every subsequent generation compare?
they will be the same
molecular signals that flows through the body and can alter the expression of genes
hormones
neither allele of a gene is completely dominant, resulting in an intermediate phenotype
incomplete dominance
mutation in a single gene affects more than one phenotypic trait
pleiotropy
In a population of people where sickle cell anemia and malaria are both present, those with one copy of the S allele are more likely to survive malaria than people who are AA homozygotes. This is an example of _______ _________.
heterozygote advantage
type of evolution in which there is a change in allele frequencies from one generation to the next
microevolution
an upstream section of DNA that includes the promoter region as well as other regulatory sequences that influence the transcription of DNA
gene control region
What are the 3 major types of selection, often portrayed on graphs?
directional, stabilizing, disruptive
contribution of individuals with one genotype compared with the average contribution of all individuals in the population
relative fitness (w)
Equilibrium frequency reached through “tug-of-war” between negative selection on deleterious alleles and new mutations
Mutation-selection balance
List all 5 of the HW conditions.
1. no mutations
2. random mating
3. no selection
4. infinite population size
5. no gene flow
a short sequence of DNA within the gene control region where activator proteins bind to initiate gene expression
enhancer