BIO 242 - FINAL EXAM QUESTIONS AND
ANSWERS GRADED A+ 2025/2026
Evolution - ANS Change in allele frequencies in a population over generations (the long-term
outcome)
Natural selection - ANS Process where individuals with heritable traits that increase fitness
leave more offspring
Fitness - ANS Reproductive success; how many viable offspring an individual leaves
Mutation - ANS Random change in DNA; ultimate source of new genetic variation
Variation - ANS Differences in traits among individuals in a population
Heritability - ANS Ability of a trait to be passed from parents to offspring
Directional - ANS selection Selection that favors one extreme trait value, shifting the
population mean
Stabilizing - ANS selection Selection that favors intermediate trait values and removes
extremes
Disruptive - ANS selection Selection that favors both extreme trait values over intermediates
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Sexual selection - ANS Selection for traits that increase mating success rather than survival
Genetic drift - ANS Random changes in allele frequencies, strongest in small populations
Bottleneck effect - ANS Loss of genetic variation after a sudden population reduction
Founder effect - ANS Genetic drift when a small group starts a new population
Gene flow - ANS Movement of alleles between populations via migration
Speciation - ANS Evolution of reproductive isolation between populations
Allopatric speciation - ANS Speciation caused by geographic separation
Sympatric speciation - ANS Speciation occurring without geographic separation
Reproductive isolation - ANS When populations can no longer interbreed successfully
Adaptive radiation - ANS Rapid diversification of one lineage into many species
Ecological opportunity - ANS Availability of new or unoccupied ecological niches
Key innovation - ANS New trait that allows exploitation of new resources or niches
Coevolution - ANS Reciprocal evolutionary change between interacting species
Selective environment - ANS Environmental factors that influence which traits are favored
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
ANSWERS GRADED A+ 2025/2026
Evolution - ANS Change in allele frequencies in a population over generations (the long-term
outcome)
Natural selection - ANS Process where individuals with heritable traits that increase fitness
leave more offspring
Fitness - ANS Reproductive success; how many viable offspring an individual leaves
Mutation - ANS Random change in DNA; ultimate source of new genetic variation
Variation - ANS Differences in traits among individuals in a population
Heritability - ANS Ability of a trait to be passed from parents to offspring
Directional - ANS selection Selection that favors one extreme trait value, shifting the
population mean
Stabilizing - ANS selection Selection that favors intermediate trait values and removes
extremes
Disruptive - ANS selection Selection that favors both extreme trait values over intermediates
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Sexual selection - ANS Selection for traits that increase mating success rather than survival
Genetic drift - ANS Random changes in allele frequencies, strongest in small populations
Bottleneck effect - ANS Loss of genetic variation after a sudden population reduction
Founder effect - ANS Genetic drift when a small group starts a new population
Gene flow - ANS Movement of alleles between populations via migration
Speciation - ANS Evolution of reproductive isolation between populations
Allopatric speciation - ANS Speciation caused by geographic separation
Sympatric speciation - ANS Speciation occurring without geographic separation
Reproductive isolation - ANS When populations can no longer interbreed successfully
Adaptive radiation - ANS Rapid diversification of one lineage into many species
Ecological opportunity - ANS Availability of new or unoccupied ecological niches
Key innovation - ANS New trait that allows exploitation of new resources or niches
Coevolution - ANS Reciprocal evolutionary change between interacting species
Selective environment - ANS Environmental factors that influence which traits are favored
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
