Genetics and Evolution Flashcards
[blank] contain genes in a linear sequence
chromosomes
[blank] are alternative forms of a gene
alleles
a [blank] allele requires only one copy to be expressed
dominant
a [blank] allele requires two copies to be expressed
recessive
a [blank] is the combination of alleles one has given genetic locus
genotype
having two of the same allele is termed [blank]
homozygous
having two different alleles is termed [blank]
heterozygous
having only one allele is termed [blank]
hemizygous
a [blank] is the observable manifestation of a genotype
phenotype
[blank] is when the effect of one allele completely masks the effect of another
complete dominance
[blank] has more than one dominant allele
codominance
[blank] has no dominant alleles; heterozygotes have intermediate phenotypes
incomplete dominance
[blank] is the proportion of a population with a given genotype who express the phenotype
penetrance
[blank] refers to the varying phenotypic manifestations of a given genotype
expressivity
mendel’s first law of segregation
states that an organism has two alleles for each gene, which segregate during meiosis, resulting in gametes carrying only one allele for a trait
mendel’s second law of independent assortment
states that the inheritance of one allele does not influence that probability of inheriting an allele for a different trait
[blank] demonstrated the transforming principle, converting non-virulent live bacteria into virulent bacteria by exposure to hear-killed virulent bacteria
the Griffith experiment
the [blank] demonstrated that DNA is the genetic material because degradation of DNA led to a cessation of bacterial transformation
the Avery-MacLeod-McCarty experiment
the [blank] confirmed that DNA is the genetic material because only radiolabled DNA could be found in bacteriophage-infected bacteria
the Hershey-Chase experiment
all of the alleles in a given population constitute the [blank]
gene pool
[blank] are changes in DNA sequence
mutations
nucleotide mutations include [blank] and [blank]
point mutations// frameshift mutations
[blank] is the substituting of one nucleotide for another
point mutations
[blank] is moving the three-letter transcriptional reading frame
frameshift mutations
a [blank] has no effect on the protein
silent mutation
a [blank] results in the substitution on one amino acid for another
missense mutation
a [blank] results in the substitution of a stop codon for an amino acid
nonsense mutation
[blank] and [blank] result in a shift in the reading frame, leading to changes for all downstream amino acids
insertions// deletions
[blank] include larger-scale mutations affecting whole segments of DNA
chromosomal mutations
[blank] occur when a large segment of DNA is lost
deletion mutations
[blank] occur when a segment of DNA is copied multiple times
duplication mutations
[blank] occur when a segment of DNA is reversed
inversion mutations
[blank] occur when a segment of DNA is moved from one chromosome to another
insertion mutations
[blank] occur when a segment of DNA is swapped with a segment of DNA from another chromosome
translocation mutations
genetic [blank] is a flow of genes between species through hybrid offspring
leakage
[blank] occurs when the composition of the gene pool changes as a result of chance
genetic drift
the [blank] results from bottlenecks that suddenly isolate a small population, leading to inbreeding and increased prevalence of certain homozygous genotypes
the founder effect
[blank] visually represent the crossing of gametes from parents to show relative genotypic and phenotypic frequencies
punnett squares
the [blank] is represented by P
the parent generation
[blank] or offspring are represented by F1, F2, etc.
filial generation
a [blank] accounts for one gene
monohybrid cross
a [blank] accounts for two genes
dihybrid cross
in [blank], sex chromosomes are usually used to indicate sex as well as genotype
sex-linked crosses
the [blank] is the likelihood of two alleles being separated during crossing over in meiosis
recombination frequency
[blank] can be made using recombination frequency as the scale in centimorgans
genetic maps
the [blank] states that if a population meets certain criteria, then the allele frequencies will remain constant
Hardy-Weinberg principle
[blank] states that chance variations exist between individuals and that advantageous variations afford the most opportunities for reproductive success
natural selection
the [blank] model accounts for mutation and recombination as mechanisms of variation and considers differential reproduction to be the mechanism for reproductive success
the modern synthesis model
[blank] considers an organism’s success to be based on the number of offspring. success in supporting offspring, and the ability of the offspring to then support others; survival of offspring or relatives ensures appearance of genes in subsequent generations
inclusive fitness
[blank] considers evolution to be a very slow process with intermittent rapid bursts of evolutionary activity
punctuated equilibrium
different types of selection lead to changes in [blank]
phenotypes
[blank] keeps phenotypes in a narrow range, excluding extremes
stabilizing selection
[blank] moves the average phenotype toward one extreme
directional selection
[blank] moves the population toward two different phenotypes at the extremes and can lead to speciation
disruptive selection
[blank] is the rapid emergence of multiple species from a common ancestor, each of which occupies its own ecological niche
adaptive radiation
a [blank] is the largest group of organisms capable of breeding to form fertile offspring
species
species are [blank] from each other by pre- or postzygotic mechanisms
reproductively isolated
[blank] occurs when two species sharing a common ancestor become more different
divergent evolution
[blank] occurs when two species sharing a common ancestor evolve in similar ways due to analogous selection pressures
parallel evolution
[blank] occurs when two species not sharing a recent ancestor evolve to become more similar due to analogous selection pressure
convergent evolution
according to the [blank], the degree of difference in the genome between two species is related to the amount of time since the two species broke off from a common ancestor
molecular clock model
