Answers
Question: Definition of Natural Selection
Correct Answer: A process in which individuals that have certain inherited traits tend to survive and
reproduce at higher rates than other individuals because of those traits.
Question: Descent with Modification
Correct Answer: Principle that each living species has descended, with changes, from other species over
time
Question: Artificial Selection
Correct Answer: Breeding organisms with specific traits in order to produce offspring with identical traits
Question: Effect of Natural Selection
Correct Answer: Over time, natural selection can increase the frequency of adaptations that are favorable
in a given environment
Question: Effect of Environment on Natural Selection
Correct Answer: If an environment changes, or if individuals move to a new environment, natural
selection may result in adaptation to these new conditions, sometimes giving rise to new species
Question: Homologous Structure
Correct Answer: Structures in different species that are similar because of common ancestry.
Question: Analagous Structures
Correct Answer: Similar function but different structure - does not show common ancestry
Question: Vestigal Structure
Correct Answer: Parts of an organism that are no longer functioning and do not affect survival
Question: Hardy-Weinberg Equation
Correct Answer: p^2 + 2pq + q^2 = 1 P=Dominant Allele Frequency 2PQ is Heterozygous Frequency
Q=Recessive Allele Frequency Determines if a population is evolving or not
Question: Genetic Drift
Correct Answer: A change in the allele frequency of a population as a result of chance events rather than
natural selection. Tend to reduce genetic variation
Question: Gene Flow
Correct Answer: The transfer of alleles between populations, tends to reduce genetic differences between
populations over time
Question: Genetic Variation
Correct Answer: Genetic differences among individuals within a population
Question: Gene Pool
Correct Answer: Combined genetic information of all the members of a particular population
, Question: Directional Selection
Correct Answer: Form of natural selection in which the entire curve moves; occurs when individuals at
one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the
curve
Question: Disruptive Selection
Correct Answer: Form of natural selection in which a single curve splits into two; occurs when individuals
at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle
Question: Stabilizing Selection
Correct Answer: Natural selection that favors intermediate variants by acting against extreme phenotypes.
Curve becomes higher and tighter in the middle.
Question: Sexual Selection
Correct Answer: A form of natural selection in which individuals with certain inherited characteristics are
more likely than other individuals to obtain mates through secondary sex characteristics.
Question: Balancing Selection
Correct Answer: Natural selection that maintains two or more phenotypic forms in a population
Question: Inbreeding Depression
Correct Answer: When individuals with similar genotypes - typically relatives - breed with each other and
produce offspring that have an impaired ability to survive and reproduce
Question: Mutation
Correct Answer: A change in a gene or chromosome
Question: Species
Correct Answer: A group of populations whose individuals may interbreed and produce viable, fertile
offspring with each other but not with members of other species
Question: Reproductive Isolation
Correct Answer: Separation of species or populations so that they cannot interbreed and produce fertile
offspring
Question: Prezygotic Barriers
Correct Answer: Barriers that impede mating or hinder fertilization
Question: Postzygotic Barriers
Correct Answer: Barriers that prevent the hybrid zygote from becoming a fertile adult.
Question: Allopatric Speciation
Correct Answer: The formation of new species in populations that are geographically isolated from one
another
Question: Sympatric Speciation
Correct Answer: The formation of new species in populations that live in the same geographic area
Question: Polyploidy