ECU EHST 2110 Exam 1 & 2 Questions and answers
Update RATED A+ NEW EDITION
Population
individuals of the same species living together within a given area
Community
different organisms are not randomly scattered, but live in together in an orderly
manner;
changes in #'s of one species within a community can have major consequences to the
whole community
Ecosystems
Functional units of nature in which living organisms interact with each other and with
the
non-living components of their environment to process energy and cycle nutrients
Example of Ecosystem
Cow pasture, salt marsh, city park, etc.
Population dynamics
The study of ecological principles that govern the ways in which populations change in
size
Biotic Potential
maximum achievable growth rate with unlimited space in the absence of limiting factors
(disease, predation, food supply)
Environmental Resistance
measured difference between biotic potential of a population and the actual observed
rate of growth
S - Curve
,Lag Phase - Slow Growth
Dramatic increase in population
Birth and Death rates are balanced and
# births = # deaths
J - Curve
Lag Phase - Slow Growth to start
population increases at rapid rates up to or above the carrying capacity, environmental
resistance becomes effective only at last moment
Frequently leads to population crashes (algal blooms / red tides)
Homeostatic Controls
Self-regulating factors (behavioral, physiological, & social responses) that are important
for controlling population size
Snowshoe hares in Canada experience population crashes every ___ - ___ years (not
predation, hunting or disease)- stress induced degeneration of liver-convulsions, coma,
death
9 - 10
Human Population Growth
Exponential growth during the 20th century
The peak global growth rate was during the
1970's
World Population Growth
Intensive efforts after World War II to improve living standards and ensure national
stability are being nullified by rapid population growth.
Thomas Malthus
Population, when unchecked, increases by a geometric ratio (2,4,8,16...) while
subsistence increases by an arithmetic ratio (1,2,3,4...)
Resource limits cause bouts of famine, war, and disease, leading to majority of world's
population with marginal standard of living
, Doubling Time
period of time in which a population doubles in size- good measure of growth
Human population "surges"
1) 600,000 years ago (development of culture)
2) 8000 BC (agricultural revolution)
3) AD 1800 (industrial/medical/scientific revolution) ex/ Smallpox vaccine (Edward
Jenner, 1796)
Birth Rate
# babies born per 1000 people per year
Where is the highest / lowest Birth Rates?
Highest = Congo (46)
Lowest = Japan (9)
Death Rate
# deaths per 1000 people per year
Death rates are bound to be higher in ________ ________
older populations
Total Fertility Rate
average # children per mother during reproductive lifetime
Growth Rate
(rate of natural increase) difference between birth rate and death rate
expressed as a percentage out of 100
Growth Rate formula
GR = (birth rate-death rate) / 10 = GR%
Increase in growth rates seen when improvements are made in what three things?
public sanitation, agriculture, and medicine
Growth rate 0.5 %
Update RATED A+ NEW EDITION
Population
individuals of the same species living together within a given area
Community
different organisms are not randomly scattered, but live in together in an orderly
manner;
changes in #'s of one species within a community can have major consequences to the
whole community
Ecosystems
Functional units of nature in which living organisms interact with each other and with
the
non-living components of their environment to process energy and cycle nutrients
Example of Ecosystem
Cow pasture, salt marsh, city park, etc.
Population dynamics
The study of ecological principles that govern the ways in which populations change in
size
Biotic Potential
maximum achievable growth rate with unlimited space in the absence of limiting factors
(disease, predation, food supply)
Environmental Resistance
measured difference between biotic potential of a population and the actual observed
rate of growth
S - Curve
,Lag Phase - Slow Growth
Dramatic increase in population
Birth and Death rates are balanced and
# births = # deaths
J - Curve
Lag Phase - Slow Growth to start
population increases at rapid rates up to or above the carrying capacity, environmental
resistance becomes effective only at last moment
Frequently leads to population crashes (algal blooms / red tides)
Homeostatic Controls
Self-regulating factors (behavioral, physiological, & social responses) that are important
for controlling population size
Snowshoe hares in Canada experience population crashes every ___ - ___ years (not
predation, hunting or disease)- stress induced degeneration of liver-convulsions, coma,
death
9 - 10
Human Population Growth
Exponential growth during the 20th century
The peak global growth rate was during the
1970's
World Population Growth
Intensive efforts after World War II to improve living standards and ensure national
stability are being nullified by rapid population growth.
Thomas Malthus
Population, when unchecked, increases by a geometric ratio (2,4,8,16...) while
subsistence increases by an arithmetic ratio (1,2,3,4...)
Resource limits cause bouts of famine, war, and disease, leading to majority of world's
population with marginal standard of living
, Doubling Time
period of time in which a population doubles in size- good measure of growth
Human population "surges"
1) 600,000 years ago (development of culture)
2) 8000 BC (agricultural revolution)
3) AD 1800 (industrial/medical/scientific revolution) ex/ Smallpox vaccine (Edward
Jenner, 1796)
Birth Rate
# babies born per 1000 people per year
Where is the highest / lowest Birth Rates?
Highest = Congo (46)
Lowest = Japan (9)
Death Rate
# deaths per 1000 people per year
Death rates are bound to be higher in ________ ________
older populations
Total Fertility Rate
average # children per mother during reproductive lifetime
Growth Rate
(rate of natural increase) difference between birth rate and death rate
expressed as a percentage out of 100
Growth Rate formula
GR = (birth rate-death rate) / 10 = GR%
Increase in growth rates seen when improvements are made in what three things?
public sanitation, agriculture, and medicine
Growth rate 0.5 %
