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Bio 7A/B: Evidence of change and results of natural selection (Chapter 18)

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

_____ selection favors one extreme form of a trait in a population.
a.
Stabilizing
c.
Natural
b.
Directional
d.
Disruptive
 

 2. 

The theory of continental drift hypothesizes that Africa and South America slowly drifted apart after once being a single landmass. The monkeys on the two continents, although similar, show numerous genetic differences. Which factor is probably the most important in maintaining these differences?
a.
geographic isolation
c.
fossil records
b.
comparative embryology
d.
comparative anatomy
 

 3. 

The variations needed for the origin of structural and physiological adaptations to occur are provided by _____.
a.
gradual changes
c.
mimicry
b.
punctuated changes
d.
mutations
 

 4. 

Upon close examination of the skeleton of an adult python, a pelvic girdle and leg bones can be observed. These features are an example of _____.
a.
comparative embryology
c.
artificial selection
b.
vestigial structures
d.
homologous structures
 

 5. 

Which of the following is not a factor that causes changes in the frequency of homozygous and heterozygous individuals in a population?
a.
migration
c.
mutations
b.
genetic drift
d.
random mating
 

 6. 

Which answer BEST shows an animal's adaptation to the tropical rain forest?
a.
camouflage in a tree frog
c.
migration of birds in winter
b.
the long neck of a giraffe
d.
an elephant's long trunk
 

 7. 

A mechanism of Darwin's proposed theory is _____.
a.
variation
c.
evolution
b.
artificial selection
d.
all of these
 

 8. 

The flying squirrel of North America closely resembles the flying phalanger of Australia. They are similar in size and have long, bushy tails and skin folds that allow them to glide through the air. The squirrel is a placental mammal, while the phalanger is a marsupial. These close resemblances, even though genetically and geographically separated by great distances, can best be explained by _____.
a.
vestigial structures
c.
divergent evolution
b.
spontaneous generation
d.
convergent evolution
 

 9. 

A pattern of evolution that results when two unrelated species begin to appear similar because of environmental conditions is _____.
a.
disruptive selection
c.
divergent evolution
b.
directional selection
d.
convergent evolution
 

 10. 

Mutations occur because of _____.
a.
the introduction of new variations through mistakes in DNA replication
b.
the introduction of new variations from elsewhere
c.
the chance survival and reproduction of new variations
d.
change in allele or genotype frequencies
 



 
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