Name ______________________________ Class___________________Date__________________
Skills Worksheet
Chapter Review
USING KEY TERMS
Complete each of the following sentences by choosing the correct term from the
word bank.
adaptation
selective breeding
species
natural selection
speciation
1. When a single population develops into two populations that can no longer
interbreed, ______________________ has occurred.
2. A group of organisms that can mate with each other to produce fertile
offspring is known as a(n) ______________________.
3. In ______________________, humans select organisms that have desirable
traits that will be passed from one generation to another.
4. A(n) ______________________ makes an organism better able to survive
in its environment.
UNDERSTANDING KEY IDEAS
Multiple Choice
_____ 5. Darwin observed variations between individuals within a population,
but he did not know how variations occur. Which of the following
causes variation in a population?
a. interbreeding
c. differences in genes
b. differences in food
d. selective breeding
_____ 6. The fossil record is a historical sequence of life indicated by fossils
found in Earth’s crust. What information about organisms in an
environment can the fossil record provide?
a. how natural selection occurs
b. how organisms in an environment changed over time
c. how selective breeding occurs
d. how genetic resistance occurs
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Population Changes
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Chapter Review continued
_____ 7. Charles Darwin puzzled over the different species of Galápagos
finches. He eventually concluded that over time, the finches adapted to
various environments on the islands. On which of the following traits
did Darwin base his conclusions?
a. eye color
b. flight patterns
c. beak size and shape
d. bone structure of the wings
_____ 8. Tarantulas defend themselves by flicking hairs into the eyes of their
predators. In a population of tarantulas, a few tarantulas do not have
these hairs. Why are the tarantulas that have these hairs more likely to
produce offspring than the hairless tarantulas are?
a. Tarantulas that have the hairs will be better able to defend
themselves.
b. Tarantulas that have the hairs will blend in with their environment.
c. The egg sacs of tarantulas that have the hairs are larger and
produce more offspring.
d. Tarantulas that have the hairs will attract more mates.
Short Answer
9. Identify two ways that organisms can be compared to provide evidence that
they arose from a common ancestor.
_______________________________________________________________
_______________________________________________________________
10. Describe evidence that supports the hypothesis that whales developed from
land-dwelling mammals.
_______________________________________________________________
_______________________________________________________________
11. Why are some animals more likely to survive to adulthood than other
animals are?
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston; a Division of Houghton Mifflin Harcourt Publishing Company.
Additions and changes to the original content are the responsibility of the instructor.
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Population Changes
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Chapter Review continued
12. Compare and contrast how natural selection enables a population to survive
under different environmental conditions.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
13. Compare the intended benefits and the possible unintended consequences of a
new pesticide.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
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Additions and changes to the original content are the responsibility of the instructor.
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Population Changes
Name ______________________________ Class___________________Date__________________
Chapter Review continued
CRITICAL THINKING
14. Concept Mapping Use the following terms to create a concept map: struggle to
survive, theory, genetic variation, Darwin, overpopulation, natural selection,
and successful reproduction.
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Additions and changes to the original content are the responsibility of the instructor.
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Population Changes
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Chapter Review continued
15. Forming Hypotheses In Australia, most of the mammals in Australia are
marsupials, which carry their young in pouches after birth. Few kinds of
marsupials are found anywhere else in the world. What is a possible
explanation for the presence of so many of these mammals in Australia?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
16. Analyzing Relationships Geologists have evidence that the continents were
once a single giant continent. This giant landform eventually split apart, and
the individual continents moved to their current positions. What role might this
drifting of continents have played in the formation of a new species?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston; a Division of Houghton Mifflin Harcourt Publishing Company.
Additions and changes to the original content are the responsibility of the instructor.
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Population Changes
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Chapter Review continued
INTERPRETING GRAPHICS
The graph on the left shows the percentage of all births by birth weight. The graph
on the right shows the probability of dying at birth by birth weight. Use the graphs
to answer the questions that follow.
17. What is the most common birth weight?
_______________________________________________________________
_______________________________________________________________
18. At which birth weight is an infant most likely to survive?
_______________________________________________________________
_______________________________________________________________
19. How do the principles of natural selection help explain why there are more
deaths among babies whose birth weights are low than among babies whose
birth weights are average?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston; a Division of Houghton Mifflin Harcourt Publishing Company.
Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
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Population Changes