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One solution to the problem of species extinction is captive breeding in zoos and gardens.What are some of the problems associated with this solution?

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The resulting population,becau...

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________ characters are continuously variable.

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For the Galapagos Islands finch species Geospiza fortis,drought conditions produced a change in the population in which the next generation had larger beaks than the previous one.What produced this change in the population?


A) Birds with larger beaks had higher fitness, so they could produce more offspring that inherited the same trait.
B) Birds with smaller beaks flew to nearby islands where food was more plentiful.
C) Birds with smaller beaks had higher fitness, but they were outcompeted by birds with larger beaks.
D) Birds with smaller beaks had higher fitness, but they waited to reproduce until wet weather returned.

E) A) and B)
F) C) and D)

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After several generations,35 percent of the island population is found to have AB+ blood.This is much higher than the percentage of AB+ people in the populations from which the original settlers came.The high percentage of AB+ blood is probably due to:


A) founder effect.
B) selective mutation.
C) disruptive selection.
D) nonrandom mating.

E) All of the above
F) B) and C)

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Cheetahs are not a healthy species.Several million years ago they were widespread in Africa and Asia,but their numbers fell drastically during the last ice age and again when they were hunted to near extinction in the nineteenth century.Now,they suffer from low survivorship (a large number of animals dying),poor sperm quality,and greater susceptibility to disease.Normally,an animal will reject tissue transplanted from another animal,but cheetahs will not reject tissue grafted on to them from another cheetah.What happened to the cheetah? How did their genetic variation change? Where does genetic variation ultimately come from? What mechanism can maintain and increase genetic variation in natural populations?

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Cheetahs went through a bottleneck twice...

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As world travel becomes easier and human populations intermix,the occurrence of what phenomenon will probably decrease?


A) mutation
B) sexual selection
C) immigration
D) founder effect and genetic drift

E) C) and D)
F) B) and C)

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The gene pool for a particular gene would include:


A) the sum of all the alleles for all the traits in the population.
B) all the alleles for a given trait in a particular individual organism of the population.
C) the sum of all the phenotypes in the population.
D) all the alleles for a particular gene in all the individuals in the population.

E) All of the above
F) A) and B)

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When a population decreases in number until a small remnant of the original population remains,a ________ has occurred.

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What is the difference between microevolution and macroevolution?


A) Microevolution is hypothetical because changes are too small to be observed, whereas macroevolution is detectable.
B) Microevolution deals with microscopic organisms, whereas macroevolution deals with larger ones.
C) Microevolution describes what happens in small populations, whereas macroevolution deals with large populations.
D) Microevolution describes changes within a population over a short period of time, whereas macroevolution describes larger changes such as the formation of new species over longer periods of time.

E) B) and D)
F) B) and C)

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Organisms that can interbreed with each other in nature but are genetically isolated from all other organisms are a:


A) genus.
B) clone.
C) species.
D) family.

E) C) and D)
F) B) and C)

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Which of the following is most likely to cause genetic changes in a population that make it better adapted to its environment?


A) nonrandom mating
B) natural selection
C) gene flow
D) genetic drift

E) A) and C)
F) A) and B)

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Which of the following is incorrectly paired?


A) gene flow: genes move from one population to another
B) bottleneck effect: changes in allele frequencies due to chance events
C) founder effect: only a small portion of an original population's gene pool are represented
D) sexual selection: mating based on phenotype

E) All of the above
F) A) and B)

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Match the following.

Premises
Chance events change allele frequencies in populations.
A small number of individuals from one area establish a new isolated population in another area.The gene frequencies of the new population differ from those of the original population.
Alleles migrate into or out of a population from neighboring populations.
Females tend to mate with brightly colored males.
Individuals with average phenotypes are favored over those with extreme phenotypes.
Responses
founder effect
gene flow
genetic drift
sexual selection
stabilizing selection

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Chance events change allele frequencies in populations.
A small number of individuals from one area establish a new isolated population in another area.The gene frequencies of the new population differ from those of the original population.
Alleles migrate into or out of a population from neighboring populations.
Females tend to mate with brightly colored males.
Individuals with average phenotypes are favored over those with extreme phenotypes.

If a species of bird with an intermediate beak size evolves into two varieties,one with large beaks and one with small beaks,this could result from disruptive selection.

A) True
B) False

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Read the statement below, and then answer the following question(s) . A small population of deer is introduced to an island. All the males have 11 to 13 points on their antlers. -If after several generations 30 percent of the males have antlers with 9 to 11 points,40 percent have antlers with 15 to 17 points,and 20 percent have antlers with 12 to 14 points,this development will have been the result of:


A) directional selection.
B) disruptive selection.
C) founder effect.
D) stabilizing selection.

E) B) and C)
F) A) and B)

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Which of the following males in a given population would be considered the most fit in an evolutionary sense?


A) one that produced 1,000 offspring, of which 100 survived but 99 did not reproduce
B) one that produced 100 offspring, of which 10 survived but 9 did not reproduce
C) one that produced 1,000 offspring, all of which died before reaching reproductive age
D) one that produced two offspring, both of which survived and produced offspring of their own

E) A) and B)
F) None of the above

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You are studying leaf size in a natural population of plants.The second season is particularly dry,and the following year the average leaf size in the population is smaller than the year before.But the amount of overall variation is the same,and the population size hasn't changed.Also,you've done experiments that show that small leaves are better adapted to dry conditions than are large leaves.Which of the following has occurred?


A) stabilizing selection
B) directional selection
C) genetic drift
D) disruptive selection

E) A) and B)
F) A) and C)

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In ________ selection,individuals with an intermediate phenotype are favored over other individuals in the population.

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Evolution by genetic drift is most obvious in:


A) invertebrate species.
B) migratory species.
C) aquatic populations.
D) small populations.

E) All of the above
F) A) and C)

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There can be more than two varieties of alleles for a particular gene in a population.

A) True
B) False

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