BIO 182 Exam 2| With Well-Structured
Questions And 100% Correct Answers|
Verified By Expert| 2025 Latest Update.
Directional selection - ANSWER ✔✔ A population's genetic variance shifts towards a new
phenotype when exposed to environmental changes (when a single phenotype is favored)
Line and equation of directional selection - ANSWER ✔✔ linear line y=mx+c
Stabilizing selection - ANSWER ✔✔ a decrease of a population's genetic variance when natural
selection favors an average phenotype and selects against extreme variation (intermediate
phenotypes are more fit than extreme ones)
Line and equation of stabilizing selection - ANSWER ✔✔ quadratic (n-shaped) y=ax^2+bx+c
How do we know which selection (directional or stabilizing) is occuring? - ANSWER ✔✔ the
r^2 of a trendline (the highest number is the one with the best fit)
Heritability definition - ANSWER ✔✔ a measure of how well differences in people's genes
account for differences in their traits
How might heritability change over time? - ANSWER ✔✔ due to the possibility of the variance
in genetic values can change
Allopatric speciation - ANSWER ✔✔ the physical isolation of a biological population by an
extrinsic barrier (geographic isolation)
Major differentiation mechanism by allopatric speciation - ANSWER ✔✔ natural selection
Example of allopatric speciation - ANSWER ✔✔ squirrels in the grand canyon
Sympatric speciation - ANSWER ✔✔ evolution of new species from a single ancestral species
while living in the same habitat
Major differentiation mechanism of sympatric speciation - ANSWER ✔✔ polyploidy
Examples of sympatric speciation - ANSWER ✔✔ cultivated corn
Genetic drift - ANSWER ✔✔ change in allele frequencies in a population from generation to
generation that occurs due to chance events
Questions And 100% Correct Answers|
Verified By Expert| 2025 Latest Update.
Directional selection - ANSWER ✔✔ A population's genetic variance shifts towards a new
phenotype when exposed to environmental changes (when a single phenotype is favored)
Line and equation of directional selection - ANSWER ✔✔ linear line y=mx+c
Stabilizing selection - ANSWER ✔✔ a decrease of a population's genetic variance when natural
selection favors an average phenotype and selects against extreme variation (intermediate
phenotypes are more fit than extreme ones)
Line and equation of stabilizing selection - ANSWER ✔✔ quadratic (n-shaped) y=ax^2+bx+c
How do we know which selection (directional or stabilizing) is occuring? - ANSWER ✔✔ the
r^2 of a trendline (the highest number is the one with the best fit)
Heritability definition - ANSWER ✔✔ a measure of how well differences in people's genes
account for differences in their traits
How might heritability change over time? - ANSWER ✔✔ due to the possibility of the variance
in genetic values can change
Allopatric speciation - ANSWER ✔✔ the physical isolation of a biological population by an
extrinsic barrier (geographic isolation)
Major differentiation mechanism by allopatric speciation - ANSWER ✔✔ natural selection
Example of allopatric speciation - ANSWER ✔✔ squirrels in the grand canyon
Sympatric speciation - ANSWER ✔✔ evolution of new species from a single ancestral species
while living in the same habitat
Major differentiation mechanism of sympatric speciation - ANSWER ✔✔ polyploidy
Examples of sympatric speciation - ANSWER ✔✔ cultivated corn
Genetic drift - ANSWER ✔✔ change in allele frequencies in a population from generation to
generation that occurs due to chance events
