BIOLOGY 151 FINAL EXAM QUESTIONS
AND ANSWERS 2026 VERIFIED.
What are Darwin's four observations/inferences that lead to natural selection? -
ANS Variation exists; traits are heritable; more offspring are produced than survive;
individuals with advantageous traits leave more offspring.
Does natural selection act on individuals or populations? - ANS Individuals are selected;
populations evolve.
What is evolution in population genetics terms? - ANS A change in allele frequencies over
time.
What are the three major sources of genetic variation? - ANS Mutation, recombination,
sexual reproduction.
What does p represent in Hardy-Weinberg? - ANS Frequency of the dominant allele.
What does q represent in Hardy-Weinberg? - ANS Frequency of the recessive allele.
What does p + q equal? - ANS 1
What does p² + 2pq + q² equal? - ANS 1
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, What does p² represent? - ANS Homozygous dominant genotype frequency.
What does 2pq represent? - ANS Heterozygous genotype frequency.
What does q² represent? - ANS Homozygous recessive genotype frequency.
What are the five Hardy-Weinberg conditions? - ANS No mutation; random mating; no gene
flow; very large population; no natural selection.
What is genetic drift? - ANS Random change in allele frequencies due to chance.
Why is genetic drift stronger in small populations? - ANS Random events have a larger
proportional effect.
What is the founder effect? - ANS A new population starts from a small group, reducing
genetic variation.
What is the bottleneck effect? - ANS A sharp reduction in population size that changes allele
frequencies by chance.
What is gene flow? - ANS Movement of alleles between populations.
What is directional selection? - ANS Selection favors one extreme phenotype.
What is stabilizing selection? - ANS Selection favors intermediate phenotypes.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 10
AND ANSWERS 2026 VERIFIED.
What are Darwin's four observations/inferences that lead to natural selection? -
ANS Variation exists; traits are heritable; more offspring are produced than survive;
individuals with advantageous traits leave more offspring.
Does natural selection act on individuals or populations? - ANS Individuals are selected;
populations evolve.
What is evolution in population genetics terms? - ANS A change in allele frequencies over
time.
What are the three major sources of genetic variation? - ANS Mutation, recombination,
sexual reproduction.
What does p represent in Hardy-Weinberg? - ANS Frequency of the dominant allele.
What does q represent in Hardy-Weinberg? - ANS Frequency of the recessive allele.
What does p + q equal? - ANS 1
What does p² + 2pq + q² equal? - ANS 1
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 10
, What does p² represent? - ANS Homozygous dominant genotype frequency.
What does 2pq represent? - ANS Heterozygous genotype frequency.
What does q² represent? - ANS Homozygous recessive genotype frequency.
What are the five Hardy-Weinberg conditions? - ANS No mutation; random mating; no gene
flow; very large population; no natural selection.
What is genetic drift? - ANS Random change in allele frequencies due to chance.
Why is genetic drift stronger in small populations? - ANS Random events have a larger
proportional effect.
What is the founder effect? - ANS A new population starts from a small group, reducing
genetic variation.
What is the bottleneck effect? - ANS A sharp reduction in population size that changes allele
frequencies by chance.
What is gene flow? - ANS Movement of alleles between populations.
What is directional selection? - ANS Selection favors one extreme phenotype.
What is stabilizing selection? - ANS Selection favors intermediate phenotypes.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 10
