BIOL 180 Exam 2 chp 4 mod 003 Q and A attested
and verified
Discrete trait correct answers *Inherited trait* that exhibits *distinct phenotypes*
Quantitative traits correct answers A trait that exhibits *continuous phenotypic variation*
Asexual reproduction correct answers *Reproduction* where offspring inherit DNA from only *one
parent*
E.g. binary fission, budding and parthenogenesis
Sexual reproduction correct answers Any form of reproduction in which *genes* from *two parents*
are combined via *fusion of gametes*, producing offspring that are *genetically distinct* from both
parents
Genetic variation correct answers Number and relative *frequency* of *alleles* present in a particular
population
Proportion of *phenotypic variation* in a trait due to *genetic* influences in a certain population in a
certain environment
Directional selection correct answers *Natural selection* that favors one *extreme phenotype*
Average phenotype of a population *changes* in *one direction*
*Reduces* overall *genetic variation*
Purifying selection correct answers *Selection* that *lowers* the *frequency* or even eliminates
*deleterious alleles*
Stabilizing selection correct answers *Natural selection* that favors *phenotypes* near the *middle* of
the *range* of *phenotypic variation*
*Reduces* overall *genetic variation* in a population
, Disruptive selection correct answers *Natural selection* that favors *extreme phenotypes* at *both
ends* of the variation range
*Genetic variation* is *maintained*
Balancing selection correct answers *Natural selection* where *no single allele* is favored in all
populations of a species at all times
*Balance* among alleles' *fitness* and *frequency*
Heterozygote advantage correct answers Pattern of *natural selection* that favors *heterozygous*
individuals compared with homozygotes
Maintains *genetic variation* in a population; a form of *balancing selection*
Frequency-dependent selection correct answers Pattern of selection in which certain *alleles* are
*favored* only when they are *rare*
A form of *balancing selection*
Acclimatization correct answers A change in an individual's *phenotype* in response to a change in
*natural environmental* conditions
Genetic correlation correct answers Evolutionary constraint in which *selection* on *one* trait causes a
*change* in *another* trait as well
May occur when the same gene(s) affects both traits
Sampling error correct answers Selection of a *non-representative* sample from some larger
population, due to *chance*
Genetic marker correct answers *Genetic locus* that can be *identified* and *traced* in populations by
lab techniques or a distinctive visible phenotype
Founder effect correct answers Change in *allele frequencies* that often occurs when a *new
population* is established from a *small group* of individuals due to *sampling error*
and verified
Discrete trait correct answers *Inherited trait* that exhibits *distinct phenotypes*
Quantitative traits correct answers A trait that exhibits *continuous phenotypic variation*
Asexual reproduction correct answers *Reproduction* where offspring inherit DNA from only *one
parent*
E.g. binary fission, budding and parthenogenesis
Sexual reproduction correct answers Any form of reproduction in which *genes* from *two parents*
are combined via *fusion of gametes*, producing offspring that are *genetically distinct* from both
parents
Genetic variation correct answers Number and relative *frequency* of *alleles* present in a particular
population
Proportion of *phenotypic variation* in a trait due to *genetic* influences in a certain population in a
certain environment
Directional selection correct answers *Natural selection* that favors one *extreme phenotype*
Average phenotype of a population *changes* in *one direction*
*Reduces* overall *genetic variation*
Purifying selection correct answers *Selection* that *lowers* the *frequency* or even eliminates
*deleterious alleles*
Stabilizing selection correct answers *Natural selection* that favors *phenotypes* near the *middle* of
the *range* of *phenotypic variation*
*Reduces* overall *genetic variation* in a population
, Disruptive selection correct answers *Natural selection* that favors *extreme phenotypes* at *both
ends* of the variation range
*Genetic variation* is *maintained*
Balancing selection correct answers *Natural selection* where *no single allele* is favored in all
populations of a species at all times
*Balance* among alleles' *fitness* and *frequency*
Heterozygote advantage correct answers Pattern of *natural selection* that favors *heterozygous*
individuals compared with homozygotes
Maintains *genetic variation* in a population; a form of *balancing selection*
Frequency-dependent selection correct answers Pattern of selection in which certain *alleles* are
*favored* only when they are *rare*
A form of *balancing selection*
Acclimatization correct answers A change in an individual's *phenotype* in response to a change in
*natural environmental* conditions
Genetic correlation correct answers Evolutionary constraint in which *selection* on *one* trait causes a
*change* in *another* trait as well
May occur when the same gene(s) affects both traits
Sampling error correct answers Selection of a *non-representative* sample from some larger
population, due to *chance*
Genetic marker correct answers *Genetic locus* that can be *identified* and *traced* in populations by
lab techniques or a distinctive visible phenotype
Founder effect correct answers Change in *allele frequencies* that often occurs when a *new
population* is established from a *small group* of individuals due to *sampling error*
