What are the elements of scientific inquiry? correct answers Observation
Question
Hypothesis
Predictions
Experimental/Observational Study
Analyze Results
Conclusion
Control group correct answers Must be in the same environment as the experimental group
Matched with the experimental group ...
Bio 152 Final Exam || A Verified A+ Pass.
What are the elements of scientific inquiry? correct answers Observation
Question
Hypothesis
Predictions
Experimental/Observational Study
Analyze Results
Conclusion
Control group correct answers Must be in the same environment as the experimental group
Matched with the experimental group except for one experimental variable
Evolution correct answers life on Earth changing over time
change in allele frequencies in a population over time
What mechanisms can cause evolutionary change? correct answers Mutation: not significant for
changing allele frequencies; highly significant for creating new genetic variation
Gene flow(migration): movement of individuals among populations; frequencies change because
loss or addition of alleles
Genetic drift (within a population): change by chance
Natural selection: change because phenotype confers (dis)advantage in a particular environment
Assumptions of Hardy-Weinberg Equilibrium correct answers random mating
no mutation
no gene flow
no genetic drift (infinite population size)
no natural selection
Purpose of Hardy-Weinberg equilibrium correct answers Null hypothesis of no evolution: if no
evolutionary mechanism is operating, then genotype frequencies should be in H-W equilibrium.
If they are in equilibrium, then evolutionary mechanisms are not acting in a significant way.
If frequencies are out of equilibrium, then at least one of the assumptions is violated, and
scientists can investigate what is causing the change.
Null hypothesis correct answers "default" hypothesis stating that there is no relationship among
experimental variables
Mutation correct answers weak agent of evolutionary change on its own, but an important source
by increasing genetic variation
raw material for other mechanisms
germ-line mutations are key because they get passed down through generations
random with regard to fitness effects
alleles don't mutate specifically into new beneficial alleles
new alleles may be deleterious, neutral, or beneficial
,mutation rate can evolve and vary among organisms (species), environments, and genes within
an organism
Requirements for evolution by natural selection to occur correct answers a trait is
variable/individuals differ in the way a particular trait is expressed
this variation is heritable/ the characteristic is passed on from parent to offspring, at least to some
degree
individual differences exist in reproductive success and survival/ some individuals leave more
offspring than others
differences in reproductive success are due to differences in the expression of the trait/ they are
dependent on the environment
---only natural selection leads to adaptations
Fitness correct answers lifetime reproductive success
can often not be measured as such, so scientists use variables like # of eggs produced in a single
breeding event to estimate fitness
Phenotypic plasticity correct answers flexible response to cues from the environment
(acclimatization); the ability to be flexible has evolved (adaptation)
Gene flow (migration) correct answers movement of individuals among populations; frequencies
change because of loss or addition of alleles
can introduce new alleles to a population
can change the allele frequency of existing alleles in a population
can counteract natural selection
Genetic drift (within a population) correct answers Change by chance; change in allele
frequencies that just happens
Sampling error in "drawing" of gametes to make zygotes
Always happens, especially in small populations
Random fluctuations in allele frequency
Natural Selection correct answers Change because phenotype confers (dis)advantage in a
particular environment
Only natural selection leads to adaptations
Differential reproductive success that happens for an environmental reason
To show that selection is operating, you need to show that the associated phenotypes help
individuals to survive and/or reproduce.
Evolution correct answers Change in allele frequencies in a population over time
Consequences of genetic drift over time correct answers loss of alleles
one allele will become fixed in the populations (fixed means frequency=1.0) until new alleles
arise through mutation
, probability that an allele will be fixed corresponds to its frequency in the population-more likely
to be fixed if higher frequency
Suppose you know the frequency of the alcohol dehydrogenase 1A(ADH1a) alleles in a human
population: allele ADH1a-4=0.21; allele ADH1a-6=0.37, allele ADH1a-7=0.422. The
probability that allele a-6 , is . correct answers lost; 0.63 (more likely to be lost than fixed)
fixed; 0.37
Genetic drift: founder effect correct answers A founding population starts with few individuals.
Small population=strong effects of genetic drift
Genetic Bottleneck correct answers Great reduction in population size; alleles lost
This is a particular case, in which genetic drift is especially strong
Genetically diverse original population--> genetically simplified population
ex: genetic bottleneck of the African cheetah. 10-12000 years ago the population decreased;
cheetahs became genetically similar.
After surviving a bottleneck, a population recovers to the point where it consists of as many
individuals as it did prior to the bottleneck. Which is most likely to apply to this population? The
post-bottleneck population... correct answers exhibits less genetic variation than before
Natural Selection in Oldfield Mice correct answers Recent adaptation-beaches and barrier islands
only 4000-6000 years old
Some mice produce more offspring than others
Coat color varies and the variation is heritable
Color of coat/background and proportion of attacks graph shows that camoflage matters
Hopi Hoekstra studies the genes involved-Mc1r and agouti
Does survival and reproduction depend on beak size? correct answers Survival was related to
beak size and seed availability in the medium ground finch, Geospitza fortis (drought in 1977)
Change in beak depth (phenotype) in the population has responded to selection--> evolution
Mark documented considerable variation in beak length in a population of owls. The frequency
of alleles changed over 20 years. He conclusively demonstrated beak length in this population is
evolving by natural selection. True or false? correct answers False
How can populations respond to selection? correct answers directional selection
stabilizing selection
disruptive seleciton
Directional Selection correct answers
Stabilizing Selection correct answers
Disruptive Selection correct answers
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