Name ______________________________ Class __________________ Date __________________
Skills Worksheet
Chapter 8 Concept Review
MATCHING
In the space provided, write the letter of the description that best matches the term
or phrase.
_____ 1. interaction between two species in
which both are harmed
_____ 2. the functional role of a species within an
ecosystem
_____ 3. one of the three main properties of a
population
_____ 4. development of adaptations as a result
of symbiotic relationships
a. density
b. growth rate
c. reproductive potential
d. carrying capacity
e. density independent
regulation
f. niche
_____ 5. maximum population that an ecosystem
can support indefinitely
g. habitat
_____ 6. close interaction between two species in
which one organism benefits while the
other organism is harmed
i. parasitism
h. competition
j. coevolution
_____ 7. the ratio of births to deaths in a
population
_____ 8. maximum number of offspring that each
member of a population can produce
_____ 9. a reduction in population size caused by
a natural disaster
_____ 10. the location where an organism lives
MULTIPLE CHOICE
In the space provided, write the letter of the term or phrase that best completes
each statement or best answers each question.
_____ 11. A territory is
a. a place where one animal lives.
b. a place where people eat.
c. an area defended by one or more individuals.
d. a place for sleeping.
_____ 12. Which of the following is an example of a parasite?
a. worm in your intestine
c. bee stinger in your arm
b. a lion hunting zebras
d. honeybee on a flower
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Environmental Science
1
Understanding Populations
Name ______________________________ Class __________________ Date __________________
Concept Review continued
_____ 13. Bacteria in your intestines are an example of mutualism if they
a. make you sick.
b. have no effect on you.
c. are destroyed by digestive juices.
d. help you break down food.
_____ 14. Predators__________kill their prey.
a. always
c. never
b. usually
d. try not to
_____ 15. What property of a population may be described as even, clumped, or
random?
a. dispersion
c. size
b. density
d. growth rate
_____ 16. What can occur if a population has plenty of food and space, and has
no competition or predators?
a. reduction of carrying capacity c. zero population growth
b. exponential growth
d. coevolution
_____ 17. A grizzly bear can be all of the following except a
a. parasite.
c. mutualist.
b. competitor.
d. predator.
_____ 18. The “co-” in coevolution means
a. apart.
b. together.
c. two.
d. predator-prey.
_____ 19. Which of the following has the greatest effect on reproductive
potential?
a. producing more offspring at a time
b. reproducing more often
c. having a longer life span
d. reproducing earlier in life
_____ 20. Members of a species may compete with one another for
a. running faster.
c. giving birth.
b. social dominance.
d. mutualism.
_____ 21. A robin that does not affect the tree in which it nests is an example of
a. parasitism.
c. mutualism.
b. commensalism.
d. predation.
_____ 22. Two species can be indirect competitors for food if they
a. use the same food source at different times.
b. have different food sources.
c. fight over food.
d. eat together peacefully.
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Environmental Science
2
Understanding Populations
TEACHER RESOURCE PAGE
Answer Key
ecosystem, while parasites are not integral
parts of their hosts. Also, the organisms in
an ecosystem do not usually harm the
ecosystem. However, parasites live on (or
in) living hosts that they do harm.
13. Disagree; rodents, deer, raccoons, and
other organisms also compete with
humans for food.
14. Disagree; reintroducing the gray wolf can
generate several types of interactions.
Hunters of wild moose, deer and elk feel
that wolves reduce the vail-able
population of game animals. This
interaction can be defined as
consumption. National Parks and Natural
Reserves favor reintroducing wolves
because revenues from hunting fees help
support maintenance and research
programs. This interaction can be defined
as mutualism.
Concept Review
MATCHING
1.
2.
3.
4.
5.
h
f
a
j
d
6.
7.
8.
9.
10.
i
b
c
e
g
MULTIPLE CHOICE
11
12.
13.
14.
15.
16.
c
a
d
b
a
b
17.
18.
19.
20.
21.
22.
a
b
d
b
b
a
Critical Thinking
ANALOGIES
1.
2.
3.
4.
b
d
c
b
5.
6.
7.
8.
REFINING CONCEPTS
c
b
b
c
15. No; within any ecosystem, each species
plays a distinct role by which it gathers
the resources necessary for life. Since
resources such as sunlight, food, and
water are limited, organisms that attempt
to use those resources in exactly the same
way will compete. Competition will lead
species to evolve different strategies for
acquiring resources and, therefore,
different niches within their environments.
Although two species can have niches that
overlap, their niches are not the same.
16. Yes; parasites rob their hosts of energy
and nutrients. For example, ticks suck
blood, and tapeworms eat food that the
host is digesting. Hosts with adaptations
that reduce the impact of their parasites
will have a better chance of surviving and
reproducing (natural selection). These
adaptations will be passed on to the host’s
offspring and eventually change the
genetic characteristics of the host’s
population.
INTERPRETING OBSERVATIONS
9. The arboreal monkey population had
better access to two readily available
resources (fruits and leaves), but the
terrestrial monkeys depended on a few
small insects and fruits falling from the
trees. Their resources could not support a
bigger population.
10. Competition. The arboreal population had
advantageous access to the same fruits
consumed by the terrestrial monkeys.
11. No. It is surviving and has access to a
second food resource (insects) that can
increase its chance for continuous
reproduction. This may allow the species
to adapt to new resources found on the
ground and eliminate its competition for
fruit with the arboreal monkeys.
AGREE OR DISAGREE
12. Disagree; the organisms that live in an
ecosystem are integral parts of that
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Environmental Science
83
Understanding Populations