BIO 3 FINAL EXAM: test questions
with complete solutions
Darwin and Wallace's theory of evolution by natural selection was revolutionary because it
_____. - correct answer ✔✔ emphasized the important of variation and change in populations
Similar gill pouches in embryos of a chick, human, and cat are an example of _____. - correct
answer ✔✔ Developmental homology
Which of the following is not one of Darwins 4 postulates for evolution by natural selection?
a-Phenotype vary in a population
b-Phenotypes are heritable
c-Phenotypes vary in relative fitness
d-Phenotypes more complex have higher fitness - correct answer ✔✔ d-Phenotypes more
complex have higher fitness
If you say that a ground squirrel has greater relative fitness than another ground squirrel in the
same population, you mean that the animal - correct answer ✔✔ has more offspring that
survive and reproduce themselves
A farmer uses triazine herbicide to control ragweed in his field. For the first few years, the
triazine works, but after several years, the farmer sees more and more ragweed. Which of these
explanations best explains what happened? - correct answer ✔✔ Triazine-resistant weeds were
more likely to survive and reproduce
Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have
lost their digestive systems. Whales have lost their hind limbs. How can natural selection
,account for these losses? - correct answer ✔✔ Each of these structures presented greater costs
than benefits in their particular environments
When nonrandom mating occurs in a population so that individuals prefer to mate with similar
individuals, allele frequencies should - correct answer ✔✔ remain the same, but homozygotes
will be overrepresented in the populations
Cystic fibrosis is a genetic disorder in homozygous recessive (ff) humans that typically causes
death in the early thirties. Over time, we would expect the f allele frequency to _____ for this
trait. - correct answer ✔✔ Decrease
In a small population of alpine foxes, an allele that increases ear length over a 10-year period
has become fixed. True or false? Long ears definitely increase the fitness of individuals - correct
answer ✔✔ True
When imbalances occur in the sex ratio of sexual species that have two sexes (i.e., other than a
50:50 ratio), the members of the minority sex often receive a greater proportion of care and
resources from parents than do the offspring of the majority sex. This is most clearly an example
of:
A) disruptive selection
B) frequency-dependent selection
C) sexual selection
D) stabilizing selection - correct answer ✔✔ B-Frequency- Dependent selection
Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more,
than this have reduced fitness. Which of the following terms best describes this situation? -
correct answer ✔✔ Stabilizing selection
, An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The
surviving population happens to have broader stripes, on average, than the initial population. If
broadness of stripes is genetically determined, what effect has the ground-squirrel population
experienced during the earthquake? - correct answer ✔✔ genetic bottleneck
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have
overlapping ranges. Pollen grains from 1 species are unable to germinate and make pollen tubes
to bring the sperm nuclei to the female ovules of the other species. These two Juniper Species
are kept separate by____ - correct answer ✔✔ Gametic isolation
Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian
Islands have different elaborate courtship rituals. These rituals involve fighting other males and
making stylized movements that attract females. What type of reproductive isolation does this
represent? - correct answer ✔✔ Behavioral isolation
Which of the following describes the most likely order of events in allopatric speciation - correct
answer ✔✔ genetic isolation, genetic drift, divergence
Why is speciation by polyploidy so common in plants? - correct answer ✔✔ Plant gametes can
be reproduced by meiosis from cells that have undergone many rounds of mitosis
A certain species of flea feeds only on pronghorn antelopes. In the western US pronghorns and
cattle often associate with one another in the same rangeland. Some of these fleas develop a
strong preference for cattle blood and mate only with other fleas that prefer cattle blood. The
host mammal can be considered as the fleas habitat. If the situation persists, and new species
evolve, this would be an example of___ - correct answer ✔✔ Sympatric speciation and
temporal isolation
Male frogs give calls that attract female frogs to approach and mate. Researchers examined
mating calls of closely related tree frogs in South America. If reinforcement is occurring, what
would you expect if you compare the calls of the two species in zones of sympatry versus zones
of allopatry? - correct answer ✔✔ Calls would be more difference in areas of sympatry
with complete solutions
Darwin and Wallace's theory of evolution by natural selection was revolutionary because it
_____. - correct answer ✔✔ emphasized the important of variation and change in populations
Similar gill pouches in embryos of a chick, human, and cat are an example of _____. - correct
answer ✔✔ Developmental homology
Which of the following is not one of Darwins 4 postulates for evolution by natural selection?
a-Phenotype vary in a population
b-Phenotypes are heritable
c-Phenotypes vary in relative fitness
d-Phenotypes more complex have higher fitness - correct answer ✔✔ d-Phenotypes more
complex have higher fitness
If you say that a ground squirrel has greater relative fitness than another ground squirrel in the
same population, you mean that the animal - correct answer ✔✔ has more offspring that
survive and reproduce themselves
A farmer uses triazine herbicide to control ragweed in his field. For the first few years, the
triazine works, but after several years, the farmer sees more and more ragweed. Which of these
explanations best explains what happened? - correct answer ✔✔ Triazine-resistant weeds were
more likely to survive and reproduce
Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have
lost their digestive systems. Whales have lost their hind limbs. How can natural selection
,account for these losses? - correct answer ✔✔ Each of these structures presented greater costs
than benefits in their particular environments
When nonrandom mating occurs in a population so that individuals prefer to mate with similar
individuals, allele frequencies should - correct answer ✔✔ remain the same, but homozygotes
will be overrepresented in the populations
Cystic fibrosis is a genetic disorder in homozygous recessive (ff) humans that typically causes
death in the early thirties. Over time, we would expect the f allele frequency to _____ for this
trait. - correct answer ✔✔ Decrease
In a small population of alpine foxes, an allele that increases ear length over a 10-year period
has become fixed. True or false? Long ears definitely increase the fitness of individuals - correct
answer ✔✔ True
When imbalances occur in the sex ratio of sexual species that have two sexes (i.e., other than a
50:50 ratio), the members of the minority sex often receive a greater proportion of care and
resources from parents than do the offspring of the majority sex. This is most clearly an example
of:
A) disruptive selection
B) frequency-dependent selection
C) sexual selection
D) stabilizing selection - correct answer ✔✔ B-Frequency- Dependent selection
Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more,
than this have reduced fitness. Which of the following terms best describes this situation? -
correct answer ✔✔ Stabilizing selection
, An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The
surviving population happens to have broader stripes, on average, than the initial population. If
broadness of stripes is genetically determined, what effect has the ground-squirrel population
experienced during the earthquake? - correct answer ✔✔ genetic bottleneck
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have
overlapping ranges. Pollen grains from 1 species are unable to germinate and make pollen tubes
to bring the sperm nuclei to the female ovules of the other species. These two Juniper Species
are kept separate by____ - correct answer ✔✔ Gametic isolation
Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian
Islands have different elaborate courtship rituals. These rituals involve fighting other males and
making stylized movements that attract females. What type of reproductive isolation does this
represent? - correct answer ✔✔ Behavioral isolation
Which of the following describes the most likely order of events in allopatric speciation - correct
answer ✔✔ genetic isolation, genetic drift, divergence
Why is speciation by polyploidy so common in plants? - correct answer ✔✔ Plant gametes can
be reproduced by meiosis from cells that have undergone many rounds of mitosis
A certain species of flea feeds only on pronghorn antelopes. In the western US pronghorns and
cattle often associate with one another in the same rangeland. Some of these fleas develop a
strong preference for cattle blood and mate only with other fleas that prefer cattle blood. The
host mammal can be considered as the fleas habitat. If the situation persists, and new species
evolve, this would be an example of___ - correct answer ✔✔ Sympatric speciation and
temporal isolation
Male frogs give calls that attract female frogs to approach and mate. Researchers examined
mating calls of closely related tree frogs in South America. If reinforcement is occurring, what
would you expect if you compare the calls of the two species in zones of sympatry versus zones
of allopatry? - correct answer ✔✔ Calls would be more difference in areas of sympatry
