chapter 44: population ecology

Question 1

what is ecology

Answer 1

Study of the interactions of organisms with other organisms and with the physical and chemical environment

Question 2

how do ecological interactions lead to evolutionary change

Answer 2

Ecological interactions act as selection pressures that result in evolutionary change

Question 3

applications of ecology

Answer 3

-Not just descriptive; its predictive
-Analyzes levels of organization & develops models & hypotheses’ that can be tested

Question 4

what is central goal

Answer 4

-develop models that explain & predict distribution & abundance of populations
-Unlimited applications!

Question 5

what is demography

Answer 5

Properties of the rate of growth and the age structure of populations

Question 6

characteristics of demographics

Answer 6

-Population density
-Population distribution
-Growth rate of a population

Question 7

what is population density

Answer 7

number of individuals per unit area

Question 8

what is population distribution

Answer 8

pattern of dispersal of individuals across a given area

Question 9

what are resources

Answer 9

abiotic & biotic components of an environment that support living organisms

Question 10

what are limiting factors

Answer 10

environmental aspects that determine where an organism lives

Question 11

what is the rate of natural increase (r)

Answer 11

Growth rate that is determined by calculating the number of individuals that are born each year and subtracting the number of individuals that die each year
r = (b – d) ÷ N

Question 12

what is biotic potential

Answer 12

highest possible rate of natural increase for a population

Question 13

what is a cohort

Answer 13

Group of individuals having a statistical factor in common, such as year of birth, in a population study

Question 14

what is survivorship

Answer 14

probability of newborn individuals of a cohort surviving to particular ages

Question 15

what is a survivorship curve

Answer 15

plot of the number of organisms surviving at each age

Question 16

what is semelparity

Answer 16

Condition of having a single reproductive effort in a lifetime

Question 17

what is iteroparity

Answer 17

repeated production of offspring at intervals throughout the life cycle of an organism

Question 18

what is exponential growth

Answer 18

-Growth of a population in which there is a rapid increase over a short period of time due to an increase in number of reproductive females in population
-Biotic potential is having full effect & birthrate is at maximum during exponential growth
-Environmental conditions prevent exponential growth

Question 19

what are the four phases of logistic growth

Answer 19

1. lag phase
2. exponential growth phase:
3. deceleration phase
4. stable equilibrium phase

Question 20

what is the lag phase

Answer 20

growth is slow because population is small

Question 21

what is the exponential growth phase

Answer 21

growth is accelerating

Question 22

what is the deceleration phase

Answer 22

growth slows down

Question 23

what is the stable equilibrium phase

Answer 23

Little if any growths; births & deaths about equal; population tends to oscillate around carrying capacity

Question 24

what is carrying capacity

Answer 24

-Largest number of organisms of a particular species that can be maintained indefinitely by a given environment
-Closer population size nears carrying capacity more likely resources will become scarce & biotic effects evident
-Depends on fluctuating conditions

Question 25

what are density-independent factors

Answer 25

-abiotic factor that affect population size independent of the population’s density
-Intensity does not increase or decrease with population size

Question 26

Which of the following studies would lie outside of an ecologist’s skill set?
a.
Management plan to clean up a section of the Mississippi River that has become polluted due to sewage discharge

b.
All of these are part of an ecologist’s skill set

c.
Developing a management plan for the preservation of an endangered species

d.
Studying the progression of an outbreak of HIV in sub-Saharan Africa

e.
Proposal to develop a solar power field on the edge of a major urban area

Answer 26

b.
All of these are part of an ecologist’s skill set

Question 27

All of the following statements about population distribution are true except
a.
Behavioral traits, such as territoriality, can affect the distribution pattern of a population

b.
A population’s distribution is calculated as the number of individuals per unit area

c.
Environmental conditions, such as climate and altitude, are often limiting factors of distribution

d.
Population distribution is the pattern of dispersal of individuals across an area of interest

Answer 27

b.
A population’s distribution is calculated as the number of individuals per unit area

Question 28

If the members of a population are small in size, mature early, and have high parity and fecundity, they are
a.
K-strategists

b.
Neither K-strategists nor r-strategists, but have characteristics of both

c.
Both K-strategists and r-strategists because they have characteristics of both

d.
r-strategists

Answer 28

d.
r-strategists

Question 29

How is environmental impact measured in a population?
a.
All of these are used to measure environmental impact

b.
Number of individuals dying each generation plus birthrates

c.
Population size and resource consumption

d.
None of these are used to measure environmental impact

e.
Population size and resource production

Answer 29

c.
Population size and resource consumption

Question 30

Which of the below resources would be considered renewable?
a.
An installation of photovoltaic (solar) panels to generate electricity for a city

b.
A piece of land that has been cleared of forest and made available for a housing development

c.
Aluminum metal that has been obtained by recycling previously used aluminum cans

d.
A previously inaccessible natural gas source that can now be extracted using a new technology

Answer 30

a.
An installation of photovoltaic (solar) panels to generate electricity for a city