IB 150 Exam 3 Study Set Exam Questions and Answers Already Passed
artificial selection - Answers deliberate manipulation by humans, as in animal and plant
breeding, of the genetic composition of a population by allowing only individuals with desirable
traits reproduce
natural selection - Answers the process by which individuals with certain heritable traits tend to
produce more surviving offspring than do individuals without those traits, often leading to a
change in makeup of the population
1) heritable variation leads to 2) differential reproductive success - Answers evolution by natural
selection occurs when...
fitness - Answers the ability of an individual to produce viable offspring relative to others of the
same species
adaptation - Answers any heritable trait that increases the fitness of an individual with that trait,
compared with individuals without that trait, in a particular environment
natural selection, genetic drift, gene flow, mutation - Answers what are the four processes that
change allele frequencies?
hardy-weinberg principle - Answers a principle of population genetics stating that genotype
frequencies in a large population do not change from generation to generation in the absence of
evolutionary processes (e.g. mutation, gene flow, selection) and non random mating
gene pool - Answers all of the alleles of all the genes in a certain population
1) random mating 2) no natural selection 3) no genetic drift (random allele frequency changes)
4) no gene flow 5) no mutation - Answers what are the five assumptions of the hardy weinberg
principle?
inbreeding - Answers mating between closely related individuals; increases homozygosity of a
population and often leads to a decline in the average fitness via selection (inbreeding
depression)
inbreeding depression - Answers in inbred offspring, fitness declines due to deleterious
recessive alleles that are homozygous, thus exposed to selection
no, b/c non random mating only changes genotype frequencies, not allele frequencies - Answers
is non random mating an evolutionary process?
deleterious - Answers in genetics, referring to any mutation, allele, or trait that reduces an
individual's fitness
sexual selection - Answers a type of natural selection that favors individuals with traits that
increase their ability to obtain mates; acts more strongly on males than females
, genetic variation - Answers the number and relative frequency of alleles present in a particular
population; also the proportion of phenotypic variation in a trait that is due to genetic rather than
environmental influences in a certain population in a certain environment
directional selection - Answers a mode of natural selection that favors one extreme phenotype
with the result that the average phenotype of a population changes in one direction; usually
reduces genetic variation in a population
purifying selection - Answers selection that lowers the frequency of or even eliminates
deleterious alleles
stabilizing selection - Answers a mode of natural selection that favors phenotypes near the
middle of the range of phenotypic variation; reduces overall genetic variation in a population
disruptive selection - Answers a mode of natural selection that favors extreme phenotypes at
both ends of the range of phenotypic variation; maintains overall genetic variation in a
population
balancing selection - Answers a mode of natural selection in which no single allele is favored in
all populations of a species at all times; instead there is a balance among alleles in terms of
frequency and fitness
heterozygote advantage - Answers a pattern of natural selection that favors heterozygous
individuals compared with homozygotes; maintains genetic variation in a population, thus is a
form of balancing selection
frequency dependent selection - Answers a pattern of selection in which certain alleles are
favored only when they are rare; a form of balancing selection
INTERsexual selection - Answers the sexual selection of an individual of one gender for mating
by an individual of the other gender (usually by female choice)
INTRAsexual selection - Answers competition among members of one gender for an
opportunity to mate (usually male-male competition)
sexual dimorphism - Answers any trait that differs between males and females
ecological/environmental selection - Answers a type of natural selection that favors individuals
with heritable traits that enhance their ability to survive and reproduce in a certain physical
and/or biological environment, excluding their ability to obtain a mate
genetic drift - Answers any change in allele frequencies due to random events; causes allele
frequencies to drift up and down randomly over time, and eventually can lead to the fixation or
loss of alleles
sampling error - Answers the selection of a non-representative sample from some larger
artificial selection - Answers deliberate manipulation by humans, as in animal and plant
breeding, of the genetic composition of a population by allowing only individuals with desirable
traits reproduce
natural selection - Answers the process by which individuals with certain heritable traits tend to
produce more surviving offspring than do individuals without those traits, often leading to a
change in makeup of the population
1) heritable variation leads to 2) differential reproductive success - Answers evolution by natural
selection occurs when...
fitness - Answers the ability of an individual to produce viable offspring relative to others of the
same species
adaptation - Answers any heritable trait that increases the fitness of an individual with that trait,
compared with individuals without that trait, in a particular environment
natural selection, genetic drift, gene flow, mutation - Answers what are the four processes that
change allele frequencies?
hardy-weinberg principle - Answers a principle of population genetics stating that genotype
frequencies in a large population do not change from generation to generation in the absence of
evolutionary processes (e.g. mutation, gene flow, selection) and non random mating
gene pool - Answers all of the alleles of all the genes in a certain population
1) random mating 2) no natural selection 3) no genetic drift (random allele frequency changes)
4) no gene flow 5) no mutation - Answers what are the five assumptions of the hardy weinberg
principle?
inbreeding - Answers mating between closely related individuals; increases homozygosity of a
population and often leads to a decline in the average fitness via selection (inbreeding
depression)
inbreeding depression - Answers in inbred offspring, fitness declines due to deleterious
recessive alleles that are homozygous, thus exposed to selection
no, b/c non random mating only changes genotype frequencies, not allele frequencies - Answers
is non random mating an evolutionary process?
deleterious - Answers in genetics, referring to any mutation, allele, or trait that reduces an
individual's fitness
sexual selection - Answers a type of natural selection that favors individuals with traits that
increase their ability to obtain mates; acts more strongly on males than females
, genetic variation - Answers the number and relative frequency of alleles present in a particular
population; also the proportion of phenotypic variation in a trait that is due to genetic rather than
environmental influences in a certain population in a certain environment
directional selection - Answers a mode of natural selection that favors one extreme phenotype
with the result that the average phenotype of a population changes in one direction; usually
reduces genetic variation in a population
purifying selection - Answers selection that lowers the frequency of or even eliminates
deleterious alleles
stabilizing selection - Answers a mode of natural selection that favors phenotypes near the
middle of the range of phenotypic variation; reduces overall genetic variation in a population
disruptive selection - Answers a mode of natural selection that favors extreme phenotypes at
both ends of the range of phenotypic variation; maintains overall genetic variation in a
population
balancing selection - Answers a mode of natural selection in which no single allele is favored in
all populations of a species at all times; instead there is a balance among alleles in terms of
frequency and fitness
heterozygote advantage - Answers a pattern of natural selection that favors heterozygous
individuals compared with homozygotes; maintains genetic variation in a population, thus is a
form of balancing selection
frequency dependent selection - Answers a pattern of selection in which certain alleles are
favored only when they are rare; a form of balancing selection
INTERsexual selection - Answers the sexual selection of an individual of one gender for mating
by an individual of the other gender (usually by female choice)
INTRAsexual selection - Answers competition among members of one gender for an
opportunity to mate (usually male-male competition)
sexual dimorphism - Answers any trait that differs between males and females
ecological/environmental selection - Answers a type of natural selection that favors individuals
with heritable traits that enhance their ability to survive and reproduce in a certain physical
and/or biological environment, excluding their ability to obtain a mate
genetic drift - Answers any change in allele frequencies due to random events; causes allele
frequencies to drift up and down randomly over time, and eventually can lead to the fixation or
loss of alleles
sampling error - Answers the selection of a non-representative sample from some larger
