Download ch.3- population dynamics notes

Name: ______________________________________________________ Date: ____ Period: ________ NOTES
Notes: Population Dynamics
What is an
• Ecosystems are _____________ systems that include both biological communities (___________
ecosystem?
factors) and physical components (____________ factors).
• Organisms ____________ with both other __________ (biotic) and _____________ (abiotic) factors
in the environment.
• Structure: Organisms of the __________ species form __________________, different populations
interact to form __________________, communities live within an ______________, and all of the
ecosystems on Earth make up the __________
How do
• Ecosystems are ____________, meaning they ___________ over time. Changes in any __________
ecosystems
or abiotic factor can lead to shifts in _____ of an ecosystem’s populations.
change?
• ____________________: the ____________ of species found in an ecosystem (can be terrestrial—
land—or ____________—ocean ecosystem). Often used to tell how _____________ an ecosystem is.
What is
• ________________: a group of organisms of the _________ species that live in a particular ________
population
• Population Dynamics: the study of why populations ___________ and what ________ them to change
dynamics?
• Populations go through __________ stages
– _____________: population size is _________________
– _____________: population size is constant (the _________)
– Decline: population size is _________________
• _____________________________: the _________________ number of individuals an ecosystem
can _____________
What four
• ____________ characteristics define a population
characteristics
– Population _________: number of individuals in a population at a given ______
define a
– Population _____________: measure of the ____________ of individuals in a certain
population?
_____________ at a particular time
– Population ____________: clumped (organisms form ____________ within a habitat—gather
around ____________), uniform (organisms live at a ________ from each other—become
__________ spaced; think of trees in a forest), _____________ (live no matter where
____________ individuals are living)
– _________ Structure: postreproductive (organisms can no longer reproduce—too ________),
reproductive (organisms are _____________ of reproduction), prereproductive (organisms
____________ capable of reproduction—too young)
How do
• Scientists can predict population ____________ based on those four characteristics
populations
• Population growth is ______________. 4 types of ______________ with population dynamics:
change?
– _________________
– __________________: the movement of individuals ______ a population
– ___________
– _________________: the movement of individuals _____ of a population
• Population ____________= birth and immigration are __________
• Population _____________ = death and emigration are ____________
• ALL populations will eventually stop ______________!
– habitats can only ______________ so many organisms
What are
• _____________ factor: a factor that ______________ the continuing ____________ of a population
limiting
– Ex: Abiotic factors (_______________ things like air, light, and __________) and biotic
factors?
factors (other __________________—competition, predation, etc.)
– ___________-dependent factor: a limiting factor that affects a population when density is
___________ (___________ population)
• Ex: competition, ____________, _______________, parasitism
• have a huge effect on population as it grows
– _____________-independent factor: a limiting factor that affects the population regardless of
___________; mostly ____________ factors
• Ex. Fire, tornado, drought, temperature, __________________
– Limiting factors affect _________ populations
What’s the
• Abiotic factors: _____________ things in an ecosystem; may be chemical or ________
difference
– Ex: ____________, oxygen, salinity, temperature, ____________, rain
between biotic • Biotic factors: all __________ components of an ecosystem.
and abiotic
– Ex: _____________, fungi, plants, _____________
factors?
• A ___________ in a biotic or abiotic factor may ___________ the size of a population if it cannot
__________ to the change or _________ the environment. A change may ___________ the size of a
population if the change enhances its ability to __________ and reproduce.
How do
• Organisms in an ecosystem constantly ____________. These interactions increase or limit the
organisms
________ of populations, maintaining the balance between available __________ and those who
interact?
consume them, generating __________ in the ecosystem.
A stable ecosystem is one where:
– The ______________ numbers of each organism change at a predictable _____
– The supply of _____________ in the physical environment fluctuates at a predictable ______
– ___________ flows through the ecosystem at a fairly _________ rate over time
• These fluctuations in populations and resources ultimately result in a ____________ ecosystem.
• Organisms interact through ______________, competition, and _______________ relationships.
• Predation: an interaction between ____________ in which one species (the predator) __________ the
other (the ___________).
– This interaction helps ___________ the population within an ecosystem, producing stability.
Changes in predator-prey populations are _______________, because at some point, ________
becomes so numerous that they are ________ to find.
– A graph of predator-prey density over time shows the cycle of fluctuations (_____).
• As the prey population ___________, the predator population ____________
• As the predator population ____________, the prey population ___________
Draw and label the graph:
•
What is
predation?
What is
competition?
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•
•
•
What is a
symbiotic
relationship?
What is
parasitism?
•
•
•
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What is
mutualism?
•
What is
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commensalism?
What are
reproduction
strategies?
•
What about
human
populations?
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In any ecosystem, organisms and populations with ___________ requirements for food, __________,
oxygen, or other _____________ may _____________ with each other for _____________ resources.
________________: a relationship that occurs when two or more organisms need the same
____________ at the same _________. Competition can be among the members of the _______ or
different species and usually occurs with organisms that ___________ the same niche.
_________: the ________ of an organism in its environment including type of food it _______, how it
___________ its food, and how it ___________ with other organisms.
Two species with identical ecological ___________ cannot coexist in the same habitat.
– Competition usually results in a ______________ in the population of a species less adapted
to compete for a particular ______________.
A symbiotic relationship exists between organisms of two _____________ species that live together in
direct _____________.
If one or the other symbiotic organisms changes, both organisms are ____________ and fall out of
________________.
Symbiotic relationships include _______________, _____________, and commensalism.
Parasitism: a symbiotic relationship in which one organism (the ____________) _____________ at
the expense of the other organism (the _________).
– Some parasites live ________ the host, like tapeworms, ___________, or bacteria
– Some parasites live on the ____________ of the host, like ________ and ticks.
Parasites ________ the host, but do not usually ______ the host. Parasitism that results in the rapid
death of the host is ______ for both the host and the parasite. The parasite needs the host to
_______ long enough for the parasite to ______________ and spread.
Mutualism: a symbiotic relationship in which ________ organisms benefit. Because the two organisms
work closely together, they help each other ___________.
– Ex: bacteria that have the ability to ________ wood live in the digestive tracts of __________
Commensalism: a symbiotic relationship in which one organism ____________, but the other is
_________ affected.
– Ex: scavenger birds eating the remains of an organism that was left behind after a
________________ finished eating.
_________________ is necessary for the survival of a species.
– __________________: species that reproduce _________ if their population falls below carrying
capacity. Produce ________ of offspring that develop rapidly (_________, dandelions, etc.)
– Competitors: species with adaptations that allow them to remain at or near their __________
capacity for long periods of time. Produce _______ offspring, and they take longer to
________, but more _______ to adulthood (wolves, elephants, etc.)
_________ key factors increased Earth’s carrying capacity for humans: habitat
____________________ and __________________
– First humans lived in Africa; over time, they spread over the ___________ planet
– Humans can live in many different _______________ (habitats) thanks to technology—a/c,
____________, shelter, etc.
– Until about _______ years ago, human population grew __________; because of ___________,
resources, etc., many people ________ before adulthood—births and deaths were ___________
Human population ___________ affects the environment: introduction of new ___________
(accidental or intentional—harms native ecosystem), ___________, and overfishing.
Questions:
1. What is the difference between a biotic factor and an abiotic factor? How are they similar?
2. What characteristics do we use to define a population?
3. What are limiting factors?
4. What are the 3 main ways organisms can interact?
5. What are the 3 types of symbiotic relationships?
6. A population of alligators live near the coastline. The population started with 10 alligators. Over time, 5
alligators were born, 2 alligators died off, 8 alligators immigrated, and 4 alligators emigrated. What is the
population size now? _________________
7. A gust of wind blows 100 dandelion seeds into a neighboring area that already has 415 dandelions. If 35
of those seeds develop into dandelions, and 70 of the original dandelions die out, how many dandelions
are in the population? _________________
8. Every month in the United States, approximately 20,000 people immigrate; 5,000 people emigrate;
150,000 babies are born; 45,000 people die.
a. What is the total population change over the month? ______________________
b. At the end of June, the US population was approximately 300,000,000. By the end of July, what is
the approximate population? _____________________________
c. At the end of June, the US population was approximately 300,000,000. By the end of the year,
what is the approximate population? ___________________________
Questions:
1. What is the difference between a biotic factor and an abiotic factor? How are they similar?
2. What characteristics do we use to define a population?
3. What are limiting factors?
4. What are the 3 main ways organisms can interact?
5. What are the 3 types of symbiotic relationships?
6. A population of alligators live near the coastline. The population started with 10 alligators. Over time, 5
alligators were born, 2 alligators died off, 8 alligators immigrated, and 4 alligators emigrated. What is the
population size now? _________________
7. A gust of wind blows 100 dandelion seeds into a neighboring area that already has 415 dandelions. If 35
of those seeds develop into dandelions, and 70 of the original dandelions die out, how many dandelions
are in the population? _________________
8. Every month in the United States, approximately 20,000 people immigrate; 5,000 people emigrate;
150,000 babies are born; 45,000 people die.
a. What is the total population change over the month? ______________________
b. At the end of June, the US population was approximately 300,000,000. By the end of July, what is
the approximate population? _____________________________
c. At the end of June, the US population was approximately 300,000,000. By the end of the year,
what is the approximate population? ___________________________