ECOLOGY WORKSHEET
NAME: ________________________
LIMITS ON POPULATION GROWTH INSTRUCTIONS:
QUESTION 1: Use the provided word bank to match the term to the most appropriate statement. STATEMENT
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TERM
A unit of measurement for populations which describes the number of individuals in a given area.
CARRYING CAPACITY
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The number of individual organisms leaving an ecosystem.
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The number of live births in an ecosystem.
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Any factor which prevents unlimited population growth in an ecosystem.
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The number of times an organism can reproduce per year.
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The total number of organisms that an ecosystem can support.
CAPACITY FOR SURVIVAL
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Non-living factors which can limit the growth of a population.
IMMIGRATION
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The number of deaths in a given population within an ecosystem.
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The maximum number of offspring an organism can produce with unlimited resources.
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The portion of an organisms life-span for which it can reproduce.
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The number of individual organisms which enter into an ecosystem.
MORTALITY
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Living factors which can limit the growth of a population.
POPULATION DENSITY
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The number of offspring that survive until reproductive age.
BIOTIC POTENTIAL BIOTIC LIMITING FACTOR EMIGRATION ABIOTIC LIMITING FACTOR
LIMITING FACTORS NATALITY PROCREATION
REPRODUCTIVE LIFE
Michael Bregar| mbregar@gmail.com
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ECOLOGY WORKSHEET
NAME: ________________________
QUESTION 2: For the questions below, write “True� if the statement is true. If the statement is false, change the underlined word to make the statement true. a)
__________
Limiting factors determine the immigration capacity of a population.
b)
__________
A limiting factor controls the growth of a population.
c)
__________
Limiting factors operate when growth is exponential.
d)
__________
Populations grow too large in the absence of limiting factors.
e)
__________
Competition is an example of a limiting factor.
f)
__________
Population size can be limited by factors such as predation.
QUESTION 3: In your own words, explain the difference between exponential population growth and logistic population growth. In your explanation include a drawing of both types of population growth. EXPONENTIAL GROWTH
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LOGISTIC GROWTH
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QUESTION 4: How are the concepts of carrying capacity and limiting factors in population growth related to each other? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Michael Bregar| mbregar@gmail.com
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ECOLOGY WORKSHEET
NAME: ________________________
QUESTION 5: Understanding abiotic and biotic limiting factors. (a) In your own words, explain the difference between an abiotic limiting factor and a biotic limiting factor. Provide examples in your explanation. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (b) Complete the table below, by identifying each statement has an abiotic limiting factor or biotic limiting factor. Provide a reason for your selection. STATEMENT
ABIOTIC OR BIOTIC
REASON
Coyotes are starving because wolves are eating the majority of the prey organisms. Buffalo are dying because recent heat wave has evaporated all the water in local watering holes. Too many deer have been born, resulting in food shortages. They are now starving to death. QUESTION 6: Understanding density-dependent and density-independent limiting factors. (a) In your own words, explain the difference between density-dependent and densityindependent factors. Provide examples in your explanation. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Michael Bregar| mbregar@gmail.com
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ECOLOGY WORKSHEET
NAME: ________________________
(b) Complete the table below, by identifying each statement as a density-independent limiting factor or a density-dependent limiting factor. STATEMENT
LIMITING FACTOR
REASON
A flood has destroyed all the gopher holes, so the gophers have now lost their habitat. A rabbit population has decreased in size, since the immigration of a wolf pack into the local ecosystem. A new unknown virus has wiped out the deer population in Northern Ontario.
QUESTION 7: Use the graph of the Wolf and Moose Populations on Isle Royale to answer the questions below.
(a) What happened to the number of wolves on Isle Royal between 1975 and 1985? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Michael Bregar| mbregar@gmail.com
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ECOLOGY WORKSHEET
NAME: ________________________
(b) What happened to the moose population when the number of wolves was low? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (c) What is the relationship between the moose and the wolves on Isle Royale? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (d) Is the number of the moose on the island a density-dependent or densityindependent limiting factor for the wolf? Explain your answer. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________
QUESTION 8: Understanding density-dependent limiting factors. (a) What is a density-dependent limiting factor? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (b) Explain when do density-dependent factors operate most strongly? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Michael Bregar| mbregar@gmail.com
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ECOLOGY WORKSHEET
NAME: ________________________
(c) List at least four density-dependent limiting factors and explain how each limits population growth. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________
QUESTION 9: Understanding density-independent limiting factors. (a) What is a density-independent limiting factor? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (b) Are density-independent limiting factors usually abiotic factors or biotic factors? Explain the reason for your answer. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (c) A small forest ecosystem has been flooded.
Although all populations would be
affected by such an event, why are populations of smaller sized organisms such as insects more likely to be affected by density-independent limiting factors? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Michael Bregar| mbregar@gmail.com
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ECOLOGY WORKSHEET
NAME: ________________________
QUESTION 10: A population continues at a stable size for many years. Suddenly, in a single season, the population size drops by half. What limiting factor is likely the cause of this, is it density-dependent, density-independent, or both?
Explain your
answer in detail. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________
QUESTION 11: Graphing Population Growth. (a) In the graph below, label the exponential growth phase, lag phase, and the stable equilibrium phase.
(b) Explain how the terms lag phase, exponential growth phase, and stable equilibrium phase relate to the growth of a population. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Michael Bregar| mbregar@gmail.com
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