ECU EHST 2110 EXAM 1 AND 2
QUESTIONS AND CORRECT
ANSWERS
What is the single greatest threat to biodiversity today? - Answer- Loss of Habitat
How many US plant and animal species are currently listed as endangered or
threatened? - Answer- 1,371 (576 animals, 795 plants)
How did the Asian Carp enter the US? - Answer- Imported by farmers in the SE US to
keep algae out of ponds
_________________________ is the most effective weapon for ensuring the survival of
native plants and animals? - Answer- Endangered Species Act
List an example of ecological and environmental services provided by some wetlands -
Answer- flood control
Which two countries have gained the most forest land between 1990 and 2010? -
Answer- China and the US
Why is topsoil loss of great concern? - Answer- Because it is a loss of soil fertility =
potential loss of crop fields
____% of worlds agricultural lands are seriously degraded - Answer- 40
Limiting Factors - Answer- Environmental conditions that limit or control where an
organism can live.
Overgrazing - Answer- most significant factor in soil degradation
Estimated ___% of rangeland has light to moderate degradation - Answer- 50
Increase in animal population has led to - Answer- overgrazing, loss of shrubs, grasses,
soil erosion
In Western America, there are ______ million publicly owned rangelands with ___%
unsatisfactory condition - Answer- 270; 60
,About ___ species of animals on federal US lands are listed as endangered or
threatened due to overgrazing - Answer- 90
Population - Answer- individuals of the same species living together within a given area
Community - Answer- 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 - Answer- 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 - Answer- Cow pasture, salt marsh, city park, etc.
Population dynamics - Answer- The study of ecological principles that govern the ways
in which populations change in size
Biotic Potential - Answer- maximum achievable growth rate with unlimited space in the
absence of limiting factors (disease, predation, food supply)
Environmental Resistance - Answer- measured difference between biotic potential of a
population and the actual observed rate of growth
S - Curve - Answer- Lag Phase - Slow Growth
Dramatic increase in population
Birth and Death rates are balanced and
# births = # deaths
J - Curve - Answer- 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 - Answer- 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 - Answer- 9 - 10
Human Population Growth - Answer- Exponential growth during the 20th century
The peak global growth rate was during the - Answer- 1970's
, World Population Growth - Answer- Intensive efforts after World War II to improve living
standards and ensure national stability are being nullified by rapid population growth.
Thomas Malthus - Answer- 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 - Answer- period of time in which a population doubles in size- good
measure of growth
Human population "surges" - Answer- 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 - Answer- # babies born per 1000 people per year
Where is the highest / lowest Birth Rates? - Answer- Highest = Congo (46)
Lowest = Japan (9)
Death Rate - Answer- # deaths per 1000 people per year
Death rates are bound to be higher in ________ ________ - Answer- older populations
Total Fertility Rate - Answer- average # children per mother during reproductive lifetime
Growth Rate - Answer- (rate of natural increase) difference between birth rate and
death rate
expressed as a percentage out of 100
Growth Rate formula - Answer- GR = (birth rate-death rate) / 10 = GR%
Increase in growth rates seen when improvements are made in what three things? -
Answer- public sanitation, agriculture, and medicine
Growth rate 0.5 % - Answer- 140 yrs doubling time
GR of 1 - Answer- doubling time of 70 yrs
GR of 2% - Answer- 35 yrs
Population declines can be associated with the
presence of _______ , _______ , and __________ - Answer- war, famine and disease
Bubonic plague - Answer- Reached Europe in 1348, killed
QUESTIONS AND CORRECT
ANSWERS
What is the single greatest threat to biodiversity today? - Answer- Loss of Habitat
How many US plant and animal species are currently listed as endangered or
threatened? - Answer- 1,371 (576 animals, 795 plants)
How did the Asian Carp enter the US? - Answer- Imported by farmers in the SE US to
keep algae out of ponds
_________________________ is the most effective weapon for ensuring the survival of
native plants and animals? - Answer- Endangered Species Act
List an example of ecological and environmental services provided by some wetlands -
Answer- flood control
Which two countries have gained the most forest land between 1990 and 2010? -
Answer- China and the US
Why is topsoil loss of great concern? - Answer- Because it is a loss of soil fertility =
potential loss of crop fields
____% of worlds agricultural lands are seriously degraded - Answer- 40
Limiting Factors - Answer- Environmental conditions that limit or control where an
organism can live.
Overgrazing - Answer- most significant factor in soil degradation
Estimated ___% of rangeland has light to moderate degradation - Answer- 50
Increase in animal population has led to - Answer- overgrazing, loss of shrubs, grasses,
soil erosion
In Western America, there are ______ million publicly owned rangelands with ___%
unsatisfactory condition - Answer- 270; 60
,About ___ species of animals on federal US lands are listed as endangered or
threatened due to overgrazing - Answer- 90
Population - Answer- individuals of the same species living together within a given area
Community - Answer- 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 - Answer- 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 - Answer- Cow pasture, salt marsh, city park, etc.
Population dynamics - Answer- The study of ecological principles that govern the ways
in which populations change in size
Biotic Potential - Answer- maximum achievable growth rate with unlimited space in the
absence of limiting factors (disease, predation, food supply)
Environmental Resistance - Answer- measured difference between biotic potential of a
population and the actual observed rate of growth
S - Curve - Answer- Lag Phase - Slow Growth
Dramatic increase in population
Birth and Death rates are balanced and
# births = # deaths
J - Curve - Answer- 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 - Answer- 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 - Answer- 9 - 10
Human Population Growth - Answer- Exponential growth during the 20th century
The peak global growth rate was during the - Answer- 1970's
, World Population Growth - Answer- Intensive efforts after World War II to improve living
standards and ensure national stability are being nullified by rapid population growth.
Thomas Malthus - Answer- 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 - Answer- period of time in which a population doubles in size- good
measure of growth
Human population "surges" - Answer- 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 - Answer- # babies born per 1000 people per year
Where is the highest / lowest Birth Rates? - Answer- Highest = Congo (46)
Lowest = Japan (9)
Death Rate - Answer- # deaths per 1000 people per year
Death rates are bound to be higher in ________ ________ - Answer- older populations
Total Fertility Rate - Answer- average # children per mother during reproductive lifetime
Growth Rate - Answer- (rate of natural increase) difference between birth rate and
death rate
expressed as a percentage out of 100
Growth Rate formula - Answer- GR = (birth rate-death rate) / 10 = GR%
Increase in growth rates seen when improvements are made in what three things? -
Answer- public sanitation, agriculture, and medicine
Growth rate 0.5 % - Answer- 140 yrs doubling time
GR of 1 - Answer- doubling time of 70 yrs
GR of 2% - Answer- 35 yrs
Population declines can be associated with the
presence of _______ , _______ , and __________ - Answer- war, famine and disease
Bubonic plague - Answer- Reached Europe in 1348, killed
