Bio 100 Final SDSU UPDATED ACTUAL
Exam Questions and CORRECT Answers
Ecology - CORRECT ANSWER - The study of the interactions between organisms and their
environment.
At what levels of organization do ecologists work? - CORRECT ANSWER - 1. Individual
organisms
2. Populations of organisms (same species)
3. Communities of organisms (different species that interact with one another)
4. Ecosystem (all living organisms that interact in a particular area)
5. Biosphere (all organisms)
Population Distribution - CORRECT ANSWER - Where populations are found on earth
What kind of factors determine distribution? - CORRECT ANSWER - 1. Abiotic (physical)
factors. Non-living like temperature, geography, water availability.
2. Biotic factors (living) predators, parasites, competition of resource
What is population density? - CORRECT ANSWER - Indicates size, The number of
organisms per unit of area/volume (used when there is a great number of organisms in a
population.
What do r, b, and d symbolize and how are they related? - CORRECT ANSWER - B = Birth
Rate
D = Death Rate
R = Population growth
, Compare and contrast exponential growth and logistic growth. - CORRECT ANSWER -
Exponential growth: Population growth that is not hindered by a limiting factor. Growth without
limits.
Logistic Growth: Population size grows and decreases within the carrying capacity due to a
limiting factor.
What is K? - CORRECT ANSWER - Maximum population size that an environment can
support.
- Result of density-dependent factos
- Birth and death rates change
- growth rate changes
Define density-dependent factors and density-independent factors. - CORRECT ANSWER -
Density dependent: Lack of food, lack of space. Pretty much things caused by over-
population/competition.
Density Independent: Fires, floods, natural disasters, etc.
What are the 3 types of survivorship curves? - CORRECT ANSWER - 1. Type I - High
survivorship until old age, then rapid decrease (humans and elephants)
2. Type II - Survivorship decreases at a steady, regular rate (birds)
3. Type III - High mortality in early life, but those that survive live long lives. (sea turtles)
Lynx-Hare Cycle - CORRECT ANSWER - Predators lag behind the pray. When the amount
of hares increase, the amount of lynx will increase because there is plenty of resources. However,
if the lynx kill too many hares, there won't be enough resources and they will decrease. Less
predators will then allow hare population to increase again.
Exam Questions and CORRECT Answers
Ecology - CORRECT ANSWER - The study of the interactions between organisms and their
environment.
At what levels of organization do ecologists work? - CORRECT ANSWER - 1. Individual
organisms
2. Populations of organisms (same species)
3. Communities of organisms (different species that interact with one another)
4. Ecosystem (all living organisms that interact in a particular area)
5. Biosphere (all organisms)
Population Distribution - CORRECT ANSWER - Where populations are found on earth
What kind of factors determine distribution? - CORRECT ANSWER - 1. Abiotic (physical)
factors. Non-living like temperature, geography, water availability.
2. Biotic factors (living) predators, parasites, competition of resource
What is population density? - CORRECT ANSWER - Indicates size, The number of
organisms per unit of area/volume (used when there is a great number of organisms in a
population.
What do r, b, and d symbolize and how are they related? - CORRECT ANSWER - B = Birth
Rate
D = Death Rate
R = Population growth
, Compare and contrast exponential growth and logistic growth. - CORRECT ANSWER -
Exponential growth: Population growth that is not hindered by a limiting factor. Growth without
limits.
Logistic Growth: Population size grows and decreases within the carrying capacity due to a
limiting factor.
What is K? - CORRECT ANSWER - Maximum population size that an environment can
support.
- Result of density-dependent factos
- Birth and death rates change
- growth rate changes
Define density-dependent factors and density-independent factors. - CORRECT ANSWER -
Density dependent: Lack of food, lack of space. Pretty much things caused by over-
population/competition.
Density Independent: Fires, floods, natural disasters, etc.
What are the 3 types of survivorship curves? - CORRECT ANSWER - 1. Type I - High
survivorship until old age, then rapid decrease (humans and elephants)
2. Type II - Survivorship decreases at a steady, regular rate (birds)
3. Type III - High mortality in early life, but those that survive live long lives. (sea turtles)
Lynx-Hare Cycle - CORRECT ANSWER - Predators lag behind the pray. When the amount
of hares increase, the amount of lynx will increase because there is plenty of resources. However,
if the lynx kill too many hares, there won't be enough resources and they will decrease. Less
predators will then allow hare population to increase again.
