BIOS 242 WEEK 9 FINAL EXAM EXAMS SET
2026 COMPLETE QUESTIONS ANSWERS
GRADED A+
◉ Natural selection. Answer: Process where individuals with
heritable traits that increase fitness leave more offspring
◉ Fitness. Answer: Reproductive success; how many viable offspring
an individual leaves
◉ Mutation. Answer: Random change in DNA; ultimate source of
new genetic variation
◉ Variation. Answer: Differences in traits among individuals in a
population
◉ Heritability. Answer: Ability of a trait to be passed from parents to
offspring
◉ Directional. Answer: selection Selection that favors one extreme
trait value, shifting the population mean
, ◉ Stabilizing. Answer: selection Selection that favors intermediate
trait values and removes extremes
◉ Disruptive. Answer: selection Selection that favors both extreme
trait values over intermediates
◉ Sexual selection. Answer: Selection for traits that increase mating
success rather than survival
◉ Genetic drift. Answer: Random changes in allele frequencies,
strongest in small populations
◉ Bottleneck effect. Answer: Loss of genetic variation after a sudden
population reduction
◉ Founder effect. Answer: Genetic drift when a small group starts a
new population
◉ Gene flow. Answer: Movement of alleles between populations via
migration
◉ Speciation. Answer: Evolution of reproductive isolation between
populations
2026 COMPLETE QUESTIONS ANSWERS
GRADED A+
◉ Natural selection. Answer: Process where individuals with
heritable traits that increase fitness leave more offspring
◉ Fitness. Answer: Reproductive success; how many viable offspring
an individual leaves
◉ Mutation. Answer: Random change in DNA; ultimate source of
new genetic variation
◉ Variation. Answer: Differences in traits among individuals in a
population
◉ Heritability. Answer: Ability of a trait to be passed from parents to
offspring
◉ Directional. Answer: selection Selection that favors one extreme
trait value, shifting the population mean
, ◉ Stabilizing. Answer: selection Selection that favors intermediate
trait values and removes extremes
◉ Disruptive. Answer: selection Selection that favors both extreme
trait values over intermediates
◉ Sexual selection. Answer: Selection for traits that increase mating
success rather than survival
◉ Genetic drift. Answer: Random changes in allele frequencies,
strongest in small populations
◉ Bottleneck effect. Answer: Loss of genetic variation after a sudden
population reduction
◉ Founder effect. Answer: Genetic drift when a small group starts a
new population
◉ Gene flow. Answer: Movement of alleles between populations via
migration
◉ Speciation. Answer: Evolution of reproductive isolation between
populations
