UW Madison Bio 101 Exam 4 |164 Questions and answers
What is biological evolution? - -Heritable change in a population across many generations.
-What is the difference between microevolution and macroevolution? - -Microevolution is
on a small scale. It is a change in a single gene. Macroevolution is on a large scale and
results in the formation of a new species.
-What is a scientific theory (definition)? - -A well-tested concept that explains a wide
range of observations.
-What is catastrophism? - -The idea presented by Georges Cuvier that major disturbances
cause change (in strata fossil record).
-What is uniformitarianism? - -The idea of Charles Lyell that gradual changes occur over
time due to natural processes (in the strata fossil record).
-What is the mechanism responsible for change in a species over time? - -Natural Selection
-Describe fitness. - -The ability of an organism to pass its genes to the next generation.
Includes surviving, finding a mate, and reproducing a new generation of offspring. Fitness
depends on the environment in which an organism lives.
-What are homologous structures? - -Functionally different features with similar
construction due to common ancestry.
-What are vestigial structures? - -Anatomical features with no apparent function, but
resemble structures of presumed ancestors.
-What are hox genes? - -Pattern-forming genes that guide body plans.
-What are analogous structures? - -Perform the same or similar function, but evolved
separately.
-What is convergent evolution? - -Evolution of similar structures in distantly related
organisms that occupy similar environments.
-What is the fossil record? - -The ordered array in which fossils appear in the strata.
-T/F: All genetic variation makes an organism more fit. - -False. Ex= albinism
-T/F: Populations are the units of evolution. - -True, not individuals.
-What is a gene pool? - -A sum of all the alleles in a population.
, -T/F: A population evolves when individuals with different genotypes survive and
reproduce at different rates. - -True. So you can see a change in gene frequency.
-What are sources of genetic variation? - -Mutation and sexual reproduction.
-What are the mechanisms of microevolution? - -Genetic drift, gene flow, mutation, and
natural selection.
-What is genetic drift? - -A process in which chance events cause unpredictable
fluctuations in allele frequencies from generation to generation. Two types: bottleneck and
founder effect.
-What is the bottleneck effect? - -When a population goes through a period in which its
size decreases. Lots of individuals and their alleles are lost. Population size later increases
but genetic diversity is still low (decrease in fitness).
-What is the Founder Effect? - -Occurs when a few individuals become isolated from a
larger population. Gene pool of new population not reflective of original population. Rare
alleles can be over-represented.
-What is gene flow? - -Genetic exchange due to the migration of fertile individuals or
gametes between populations. It tends to reduce differences between populations that
have accumulated because of natural selection or genetic drift.
-T/F: Gene flow can both increase and decrease the fitness of a population. - -True
-What is natural selection? - -Accumulates and maintains favorable genotypes in a
population. Must have genetic variation to occur.
-What is directional selection? - -A form of natural selection that favors individuals at one
extreme of a phenotypic distribution.
-What is stabilizing selection? - -A form of natural selection that favors individuals with
intermediate phenotypes. Average is good, extreme is bad.
-What is disruptive selection? - -A form of natural selection that favors extreme
phenotypes. Increases variation.
-What is balancing selection? - -A form of natural selection where multiple alleles are
maintained in the gene pool of a population at frequencies higher than expected from
genetic drift alone. The fitness of a phenotype depends on its frequency relative to other
phenotypes in a given population.
-What is the heterozygote advantage? - -The heterozygote genotype has a higher relative
fitness than either the homozygote dominant or homozygote recessive genotype.
What is biological evolution? - -Heritable change in a population across many generations.
-What is the difference between microevolution and macroevolution? - -Microevolution is
on a small scale. It is a change in a single gene. Macroevolution is on a large scale and
results in the formation of a new species.
-What is a scientific theory (definition)? - -A well-tested concept that explains a wide
range of observations.
-What is catastrophism? - -The idea presented by Georges Cuvier that major disturbances
cause change (in strata fossil record).
-What is uniformitarianism? - -The idea of Charles Lyell that gradual changes occur over
time due to natural processes (in the strata fossil record).
-What is the mechanism responsible for change in a species over time? - -Natural Selection
-Describe fitness. - -The ability of an organism to pass its genes to the next generation.
Includes surviving, finding a mate, and reproducing a new generation of offspring. Fitness
depends on the environment in which an organism lives.
-What are homologous structures? - -Functionally different features with similar
construction due to common ancestry.
-What are vestigial structures? - -Anatomical features with no apparent function, but
resemble structures of presumed ancestors.
-What are hox genes? - -Pattern-forming genes that guide body plans.
-What are analogous structures? - -Perform the same or similar function, but evolved
separately.
-What is convergent evolution? - -Evolution of similar structures in distantly related
organisms that occupy similar environments.
-What is the fossil record? - -The ordered array in which fossils appear in the strata.
-T/F: All genetic variation makes an organism more fit. - -False. Ex= albinism
-T/F: Populations are the units of evolution. - -True, not individuals.
-What is a gene pool? - -A sum of all the alleles in a population.
, -T/F: A population evolves when individuals with different genotypes survive and
reproduce at different rates. - -True. So you can see a change in gene frequency.
-What are sources of genetic variation? - -Mutation and sexual reproduction.
-What are the mechanisms of microevolution? - -Genetic drift, gene flow, mutation, and
natural selection.
-What is genetic drift? - -A process in which chance events cause unpredictable
fluctuations in allele frequencies from generation to generation. Two types: bottleneck and
founder effect.
-What is the bottleneck effect? - -When a population goes through a period in which its
size decreases. Lots of individuals and their alleles are lost. Population size later increases
but genetic diversity is still low (decrease in fitness).
-What is the Founder Effect? - -Occurs when a few individuals become isolated from a
larger population. Gene pool of new population not reflective of original population. Rare
alleles can be over-represented.
-What is gene flow? - -Genetic exchange due to the migration of fertile individuals or
gametes between populations. It tends to reduce differences between populations that
have accumulated because of natural selection or genetic drift.
-T/F: Gene flow can both increase and decrease the fitness of a population. - -True
-What is natural selection? - -Accumulates and maintains favorable genotypes in a
population. Must have genetic variation to occur.
-What is directional selection? - -A form of natural selection that favors individuals at one
extreme of a phenotypic distribution.
-What is stabilizing selection? - -A form of natural selection that favors individuals with
intermediate phenotypes. Average is good, extreme is bad.
-What is disruptive selection? - -A form of natural selection that favors extreme
phenotypes. Increases variation.
-What is balancing selection? - -A form of natural selection where multiple alleles are
maintained in the gene pool of a population at frequencies higher than expected from
genetic drift alone. The fitness of a phenotype depends on its frequency relative to other
phenotypes in a given population.
-What is the heterozygote advantage? - -The heterozygote genotype has a higher relative
fitness than either the homozygote dominant or homozygote recessive genotype.
