Ch54

Question 1

levels of ecology

Answer 1

• Population ecology – single populations
• Community ecology – interactions between species
• Systems ecology – the pattern of interactions within an ecosystem
• Global ecology – ecology on the scale of the planet

Question 2

Survivorship curve slope

Answer 2

Slope of curve determines
relative rate of mortality

Question 3

Population growth rate formula

Answer 3

r = (b − d) + (i − e)
r = rate of population increase; b = birth rate; d = death rate; i
= immigration; e = emigration

Question 4

Biotic potential

Answer 4

ri = (b − d)

Question 5

Density-dependent factors

Answer 5

• resource shortages
• Disease
• Increased predation

Question 6

Density-Independent

Answer 6

Rate of growth of a population can also be limited by factors unrelated to the size of the population

Question 7

Population dynamics

Answer 7

change in population size over
time
* Must survive (death rates)
* Must reproduce (birth rates)

Question 8

r-Selected Populations

Answer 8

Populations far below carrying capacity,
Evolutionary success by rapid population growth (increase r)

Question 9

K-selected populations

Answer 9

adapted to thrive when population is near its carrying capacity and push K even higher
* Costs of reproduction tend to be high
* individuals must compete and utilize resources efficiently.
* Can lower reproductive rates.

Question 10

r vs. K

Answer 10

Stable environments favor K selection
* Largest populations for organism exquisitely tuned to environment
Unstable environments favor r selection
* Environment is a moving target

Question 11

Epidemic

Answer 11

more localized outbreak

Question 12

Pandemic

Answer 12

widespread disease outbreak that extends over
multiple countries

Question 13

R0

Answer 13

the disease reproduction number

Question 14

Ecology

Answer 14

study of how organisms relate to one another and their environments

Question 15

Population

Answer 15

group of individuals of the same species that live in a specific area at the same time and interact

Question 16

Metapopulation

Answer 16

A population of populations

Question 17

Range

Answer 17

Where the population is found

Question 18

Distribution

Answer 18

How it is organized within its range

Question 19

Dynamics

Answer 19

How its characteristics change over time

Question 20

Source-Sink Metapopulations

Answer 20

populations in better areas (source) bolster the
population in poorer areas (sink)

Question 21

What aspects of the environment influence organisms’ ecology?

Answer 21

Temperature, precipitation, elevation, soil conditions, nutrients, resource
availability, etc

Question 22

What types of responses to environmental factors do we observe in organisms?

Answer 22

Morphological, Physiological, Behavioral

Question 23

Bergmann’s Rule

Answer 23

Among closely related species, those in colder climates tend to be larger or thicker

Question 24

Demography

Answer 24

Quantitative like sex ratios, generation times, growth
rates, population size, age structure, etc.

Question 25

What aspects of a population’s structure are influenced by its demography?

Answer 25

● Population growth can be influenced by the population’s sex ratio ● Number of births directly related to number of female ● Populations with short generations can increase in size more quickly

Question 26

Life-history traits

Answer 26

Natural selection favors traits that maximize the number of surviving offspring left in the next generation by an individual organism. Two factors affect this quantity.. -How long an individual lives -How many young it produces each year

Question 27

Trade off

Answer 27

limited resources vs. increased reproduction

Question 28

Exponential growth

Answer 28

observed in ideal, low-stress environments with abundant resources and minimal ecological pressures. (small populations)

Question 29

Logistic growth

Answer 29

occurs when environmental resistance and resource limitations impose checks on population size, creating stability around the carrying capacity

Question 30

N

Answer 30

Population Size ● Births and immigration increase N ● Deaths and emigration decrease N

Question 31

r

Answer 31

Intrinsic Growth Rate (birth rate minus death rate)

Question 32

K

Answer 32

Carrying Capacity (max. number of individuals) ● Resource availability ● Environmental quality (eg. pollution, habitat destruction) ● Predator-prey dynamics and competition

Question 33

What happens to the growth rate as a population approaches K?

Answer 33

As a population approaches its carrying capacity (K), the growth rate slows down and eventually approaches zero. This behavior occurs because of increasing environmental resistance (eg. resource limitation, increased competition, predation pressures)-factors that limit population growth as resources become scarce.

Question 34

SARS-CoV-2

Answer 34

Become more contagious

Question 35

Influenza

Answer 35

Overcome host’s immunity

Question 36

Myxoma

Answer 36

Become less lethal

Question 37

Allen’s Rule

Answer 37

those living in colder climates tend to have shorter extremities/limbs than those living in warmer climates