BSC 2011 Exam 1 | University of South Florida |
UPDATED Questions with 100% Verified Answers
Q1: Fitness
A: the ability of an organism to produce viable offspring
Q2: Adaptation
A: a heritable trait that is associated with high fitness - promotes a population's survival and
reproduction in a particular environment
Q3: Theory
A: an explanation or set of hypotheses that attempt to explain a large and pervasive
phenomenon
Q4: Directional Selection
A: occurs on a trait when one extreme phenotype is favored - causes the frequency curve
to shift to either the left or right
Q5: Impacts of Directional Selection on Traits
A: 1. The average changes, because individuals with one extreme have higher fitness while
individuals with another extreme have lower fitness
2. The amount of overall variation decreases, because alleles associated with one
extreme are being eliminated
Q6: Stabilizing Selection
A: occurs on a trait when individuals with the average value have highest fitness and
individuals with both extreme phenotypes have lower fitness - causes the frequency
curve to become narrower around the average phenotype
, Q7: Impacts of Stabilizing Selection on Traits
A: 1. The average does not change, because individuals with intermediate values of the trait
have the highest fitness
2. The amount of overall variation decreases, because alleles associated with both
extremes are being eliminated
Q8: Genetic Drift
A: any change in allele frequencies that is due to chance - can lead to allele fixation or loss,
and has a much larger effect on allele frequencies in small populations versus large
populations
Q9: Founder events
A: occur when a relatively small number of individuals disperse to a new habitat and found,
or establish, a completely new population - causes genetic drift and reduces genetic
variation in the affected population
Q10: Bottleneck events
A: occur when a species undergoes a large and rapid decrease in population size due to a
disease epidemic, catastrophic storm, or other change - alleles that survive do so largely
by chance. Causes genetic drift and reduces genetic variation in the affected population
Q11: Gene Flow
A: causes allele frequencies to change when individuals and their alleles move from one
population to join another population - makes allele frequencies in two populations more
similar (homogenizes allele frequencies among populations). This change can be
maladaptive in a new environment
Q12: Evolution
A: a change in allele frequencies over time - can be adaptive or random
Q13: Mutation
A: any change in the nucleotide sequence in DNA - the only process that creates entirely
new alleles, and thus, genetic variation
UPDATED Questions with 100% Verified Answers
Q1: Fitness
A: the ability of an organism to produce viable offspring
Q2: Adaptation
A: a heritable trait that is associated with high fitness - promotes a population's survival and
reproduction in a particular environment
Q3: Theory
A: an explanation or set of hypotheses that attempt to explain a large and pervasive
phenomenon
Q4: Directional Selection
A: occurs on a trait when one extreme phenotype is favored - causes the frequency curve
to shift to either the left or right
Q5: Impacts of Directional Selection on Traits
A: 1. The average changes, because individuals with one extreme have higher fitness while
individuals with another extreme have lower fitness
2. The amount of overall variation decreases, because alleles associated with one
extreme are being eliminated
Q6: Stabilizing Selection
A: occurs on a trait when individuals with the average value have highest fitness and
individuals with both extreme phenotypes have lower fitness - causes the frequency
curve to become narrower around the average phenotype
, Q7: Impacts of Stabilizing Selection on Traits
A: 1. The average does not change, because individuals with intermediate values of the trait
have the highest fitness
2. The amount of overall variation decreases, because alleles associated with both
extremes are being eliminated
Q8: Genetic Drift
A: any change in allele frequencies that is due to chance - can lead to allele fixation or loss,
and has a much larger effect on allele frequencies in small populations versus large
populations
Q9: Founder events
A: occur when a relatively small number of individuals disperse to a new habitat and found,
or establish, a completely new population - causes genetic drift and reduces genetic
variation in the affected population
Q10: Bottleneck events
A: occur when a species undergoes a large and rapid decrease in population size due to a
disease epidemic, catastrophic storm, or other change - alleles that survive do so largely
by chance. Causes genetic drift and reduces genetic variation in the affected population
Q11: Gene Flow
A: causes allele frequencies to change when individuals and their alleles move from one
population to join another population - makes allele frequencies in two populations more
similar (homogenizes allele frequencies among populations). This change can be
maladaptive in a new environment
Q12: Evolution
A: a change in allele frequencies over time - can be adaptive or random
Q13: Mutation
A: any change in the nucleotide sequence in DNA - the only process that creates entirely
new alleles, and thus, genetic variation
