Name
Class
Date
CHAPTER 19 ACTIVE READING WORKSHEETS
P OPULATIONS
Section 19-2: Measuring Populations
Read the passage below, which covers topics from your textbook.
Answer the questions that follow.
The exponential model of population growth describes a population that increases rapidly after only a few generations; the larger
the population gets, the faster it grows. This is called exponential
growth. In the construction of an exponential model of population
growth, it is assumed that birth rates and death rates remain constant, however large the population becomes.
The logistic model of population growth builds on the exponential model but accounts for the influence of limiting factors which
restrain growth. Birthrates and death rates are not constant, but
vary with population size; birthrates decline and death rates rise
as the population grows. The logistic model includes a new term,
carrying capacity (symbolized by K), the number of individuals
the environment can support over time.
Read the question and write your answer in the space provided.
Recognizing Similarities and Differences
1. What are the similarities and differences of the exponential model and logistic model of
population growth?
Read the question and write your answer in the space provided.
SKILL:
Vocabulary Development
2. What is the meaning of restrain in the passage?
_____________________________________________________________________________
Circle the letter of the phrase that best completes the statement.
3. Carrying capacity refers to the number of
a. females in a population.
b. abiotic factors in an environment.
74
Modern Biology Active Reading Worksheets
c. individuals an environment can support over time.
d. populations present in a particular environment.
Section 19-2
Copyright © by Holt, Rinehart and Winston. All rights reserved.
SKILL:
nitrogen gas
nitrogen-fixing bacteria
ecosystem
Ammonification is the act of releasing ammonia
compounds.
8. d
CHAPTER 19
Populations
SECTION 19-1: UNDERSTANDING
POPULATIONS
1. a. random distribution
b. clumped distribution
c. even distribution
2. uniform or conforming to the same principles
3. a
SECTION 19-2: MEASURING POPULATIONS
1. Both models describe the influence that
birthrates and death rates have on population
size. In the exponential model, it is assumed that
birthrates and death rates remain constant and
that the larger the population gets, the faster it
grows. In the logistic model, it is assumed that
birthrates decline and death rates rise with population size due to limiting factors.
2. to limit or restrict
3. c
SECTION 19-3: HUMAN POPULATION GROWTH
1.
2.
3.
4.
5.
6.
developing countries
developed country
0.003 per capita
exceed its birth rates
0.015 per capita
a
CHAPTER 20
Community Ecology
SECTION 20-1: SPECIES INTERACTIONS
1. similarities and differences
2. In the passage, the term derive means “to obtain
or receive.”
3. a
SECTION 20-2: PATTERNS IN COMMUNITIES
1.
2.
3.
4.
5.
6.
7.
206
identifying main ideas
species extinction
c
primary succession
farming
their seeds
d
Modern Biology Active Reading Worksheets
CHAPTER 21
Ecosystems
SECTION 21-1: TERRESTRIAL BIOMES
1. tundras and deserts
2. savanna
3. c
SECTION 21-2: AQUATIC ECOSYSTEMS
1. about 70 percent
2. intertidal zone, neritic zone, oceanic zone
3. The oceanic zone lies beyond the continental
shelf.
4. Both zones are subdivisions of the oceanic zone.
The pelagic zone is the open ocean, while the
benthic zone is the ocean bottom.
5. a. Oceanic zone
b. Neritic zone
c. Intertidal zone
d. Pelagic zone
e. Aphotic zone
f. Benthic zone
6. factor or trait that is not constant
7. c
CHAPTER 22
Humans and the Environment
SECTION 22-1: AN INTERCONNECTED PLANET
1. Answers include: provide food, fuel, medicines,
and useful chemicals, and recycle wastes.
2. biologist, E.O. Wilson
3. d
SECTION 22-2: ENVIRONMENTAL ISSUES
1. The thinning areas in the ozone layer may result
in an increase in human skin cancer and also
disrupt ecosystems by harming plants and
photosynthetic algae.
2. In the passage, the term depletion means “to
decrease or lessen quantity.”
3. c
SECTION 22-3: ENVIRONMENTAL SOLUTIONS
1. As the human population has increased, natural
resources have been destroyed. The distruction
of natural resources has brought about losses in
biodiversity.
2. field of study
3. b
CHAPTER 23
Bacteria
SECTION 23-1: PROKARYOTES
1. thermoacidophiles
2. c
Answer Key
Copyright © by Holt, Rinehart and Winston. All rights reserved.
4.
5.
6.
7.