EXAM 5 Flashcards
The study of the relationships of organisms with one another (biotic) and with their non-living environment (abiotic) is ________.
Ecology
The goal of ecology is to explain why certain organisms are ________________________________. (____________ and ____________)
The goal of ecology is to explain why certain organisms are found where they are. (Distribution and abundance)
What are the 2 ways of studying ecology?
descriptive and dynamic
Levels of Organization in Ecology:
- S_____
- P_________
- C__________
- E_________
- B_____
- B________
Basic level to start studying Ecology: _________
Levels of Organization in Ecology:
- Species
- Population
- Communities
- Ecosystems
- Biomes
- Biosphere
Biosphere Basic level to start studying Ecology: population
a group of individuals of a given species that live in the same area at the same time
population
Characteristics of a Population:
– S___ (________)
– D______
– G_____
– R___
Characteristics of a Population:
– Size (descriptive)
– Density
– Growth
– Role
Population Size has a ______ influence on survival:
►_____ population = good survival possibilities
►_____ population = not good, due to
- Natural ________, and
- Genetic problems, such as:
_______
lowered _____
lack of _________
Population Size has a direct influence on survival:
►Large population = good survival possibilities
►Small population = not good, due to:
- Natural disasters
- Genetic problems, such as:
inbreeding
lowered vigor
lack of variability
Population Density:
(How _____ or ___ apart are organisms found)
Has a related ___________ or dispersion:
– ________ (aggregated): elephants herd, school of fish
– _______ (Regular or Even): desert bushes
– _____
Population Density:
(How close or far apart are organisms found)
Has a related distribution or dispersion:
– Clumped (aggregated): elephants herd, school of fish
– Uniform (Regular or Even): desert bushes
– Random
maximum rate at which population can increase in optimal conditions
Biotic Potential
limits set by the living and non-living environments (availability of food, space, competition, interactions, natural events)
environmental resistance
All populations show growth as a result of a relation between ______ _________ and ____________ __________.
All populations show growth as a result of a relation between biotic potential and environmental resistance.
____________ growth occurs when a population continuously grows at a _____ __________ of its size at the beginning of each time period,
which results in a __-_______ growth curve.
Exponential growth occurs when a population continuously grows at a fixed percentage of its size at the beginning of each time period,
which results in a J- shaped growth curve.
__________ ____ describes the amount of time it takes to double its population at its current state of growth and can be calculated as __/__ (r = growth rate).
Doubling time describes the amount of time it takes to double its population at its current state of growth and can be calculated as .7/r (r = growth rate).
Biotic potential (max growth in optimal conditions) is influenced by:
(1) Age at which the organism first __________
(2) Reproduction _________
(3) Average _________
(4) Length of the organism’s ___________ ____ ____
(5) _____ rate
Biotic potential (max growth in optimal conditions) is influenced by:
(1) Age at which the organism first reproduces
(2) Reproduction frequency
(3) Average offspring
(4) Length of the organism’s reproductive life span
(5) Death rate
Populations use what two main strategies to control population size?
K-strategist
&
r-strategist
K- strategist:
– Limited by _______ ________ of environment
– Generally show _________ growth curve
– Tend to live in fairly ______ habitats, _________ late, few _________ (_____ size, ______ slowly, receive intensive ________ ____, generations relatively ____)
– i.e. whales, rhinoceros, coconut palms, whooping cranes
K- strategist:
– Limited by carrying capacity of environment
– Generally show sigmoidal growth curve
– Tend to live in fairly stable habitats, reproduce late, few offspring (large size, mature slowly, receive intensive parental care, generations relatively long)
– i.e. whales, rhinoceros, coconut palms, whooping cranes
r – strategist:
– ________ rate of growth is most important
– Tend to live in ________ environments
– Reproduce _____, have ____ offspring
– Offspring are _____ & mature ____,
without _______ ___
– Generations are relatively _____
– i.e. bacteria, annual plants, protozoa, earthworm
r – strategist:
– Intrinsic rate of growth is most important
– Tend to live in unstable environments
– Reproduce early, have many offspring
– Offspring are small & mature fast,
without parental care
– Generations are relatively short
– i.e. bacteria, annual plants, protozoa, earthworm
Exponential growth either _______ _________ or _______.
Exponential growth either reaches stability or crashes.
Exponential growth can be caused by:
temporary increase of ____ _____,
introduction of ______ _______,
reduction of _________,
or protection of _______.
Exponential growth can be caused by:
temporary increase of food supply,
introduction of exotic species,
reduction of predators,
or protection of species.
________ _____ occurs when populations ________ to the _______ number sustainable by their environment or ________ ________ (K), without damage to the ecosystem and results in an __-______ growth curve.
Logistic growth occurs when populations increase to the maximum number sustainable by their environment or carrying capacity (K), without damage to the ecosystem and results in an s-shaped growth curve.
Consequences of Exceeding K (carrying capacity):
⇒ Damage to _________
⇒ Further _________ __
⇒_________ or ___________ of population
Consequences of Exceeding K (carrying capacity):
⇒ Damage to resources
⇒ Further decreased K
⇒ Reduction or elimination of population
Environmental resistance can be classified into two broad categories
_______-___________ factors
_______-_________ factors
Environmental resistance can be classified into two broad categories
Density-independent factors
Density-dependent factors
_______-__________ factors limit
populations regardless of their density.
Examples:
c_____, w_____, p________, p________, o_________
Density-independent factors limit
populations regardless of their density.
Examples:
climate, weather, pesticides, pollutants, overhunting
Density-________ factors:
become ____ effective as population density _______,
exert ______ feedback effect on population size
(birth rate ____, death rate ________, __-curve results),
and include community interactions such as p________, p________, and c__________.
Density-dependent factors:
become more effective as population density increases,
exert negative feedback effect on population size (birth rate drops, death rate increases, s-curve results),
and include community interactions such as predation, parasitism, and competition.
Predator-prey affect each other in cycles:
Availability of ____
⇒ ________ predators
⇒ ________ prey
⇒________ predators
Predator-prey affect each other in cycles:
Availability of prey
⇒ increase predators
⇒ decrease prey
⇒decrease predators
Parasitism involves a ________ living on or in a ____ ________, _______ on it and _________ it but generally not _______ it.
Examples: ________ causing Lyme disease,
some _____, intestinal _____, _____, and some ______
Parasitism involves a parasite living on or in a host organism, feeding on it and weakening it but generally not killing it.
Examples: bacterium causing Lyme disease,
some fungi, intestinal worms, ticks, and some protists
describes the interaction among individuals who attempt to utilize a that is limited relative to the for it, and ________ as populations grow near carrying capacity.
Competition describes the interaction among individuals who attempt to utilize a shared resource that is limited relative to the demand for it, and intensifies as populations grow near carrying capacity.
may be divided into two groups:
is between individuals of different species
is between individuals of the same species
Competition may be divided into two groups:
Interspecific competition is between individuals of different species
Intraspecific competition is between individuals of the same species
The size of a population at any given time is the result of complex interactions between _________ and _________ _________.
The size of a population at any given time is the result of complex interactions between interspecific and intraspecific competition.
____________ __ ____________ describes the pattern of survival in a population
____ ______ track groups of organisms born at the same time throughout their life span and can generate ____________ _________.
Survivorship in Populations describes the pattern of survival in a population
Life tables track groups of organisms born at the same time throughout their life span and can generate Survivorship Curves.
What three types of survivorship curves can be distinguished?
late loss
constant loss
early loss
____ loss curves are seen in many animals with ___ _________ that receive substantial ________ ____.
examples: ______ and many large _______
Late loss curves are seen in many animals with few offspring that receive substantial parental care.
examples: humans and many large mammals
________ ____ curves are an approximate straight line, indicating an equal chance of ________________.
example: some _____ species
Constant loss curves are an approximate straight line, indicating an equal chance of dying at any age
example: some bird species
_____ ____ ______show high early mortality as ____ _________ fail to become established.
examples: most ___________ and ____
Early loss curves show high early mortality as most offspring fail to become established.
examples: most invertebrates and fish
Change in Human Populations
Human Population Continues to ____ _______
Technological Advances Have Increased Earth’s _______ ________
Demographic __________ Helps _______ Populations
Population Growth Is ________ Distributed
The ______ ___ ________ of a Population Predicts Its ______ ______
Fertility in Europe Is _____ ___________ Level
The United States Populations Is _______ _______
Change in Human Populations
Human Population Continues to Grow Rapidly
Technological Advances Have Increased Earth’s Carrying Capacity
Demographic Transition Helps Stabilize Populations
Population Growth Is Unevenly Distributed
The Current Age Structure of a Population Predicts Its Future Growth
Fertility in Europe Is Below Replacement Level
The United States Populations Is Growing Rapidly
the branch of science that studies the changing human population
demography
Demographers track _________ _______ in different _________ and _______.
Demographers track population changes in different countries and regions.
___________ ____ are used to _________ ________ in public health, housing, education, employment, immigration, and environmental protection.
Demographic data are used to formulate policies in public health, housing, education, employment, immigration, and environmental protection.
Over the ____ ______, the rate of human population growth seems to be ________, with 75-80 million people added per year, indicating that we may be entering the _____ ____ of the _______.
Over the last decade, the rate of human population growth seems to be stabilizing, with 75-80 million people added per year, indicating that we may be entering the final bend of the s-curve.
Several technological ___________ have greatly influenced the human ability to make _______ available:
_______ & _______
_______
_______-_______
Several technological revolutions have greatly influenced the human ability to make resources available:
technical & cultural
agricultural
industrial-medical
_______ & _____ revolution occurred in ______ humans.
The invention of ______ and _______ increased food availability, and the discovery of _____ and creation of _____ and _____ increased their _____ _____.
Technical & cultural revolution occurred in primitive humans.
The invention of tools and weapons increased food availability, and the discovery of fire and creation of shelters and clothing increased their habitable range.
Agricultural revolution occurred beginning c. _______ when ________ and ______ were domesticated.
Agricultural revolution occurred beginning c. 8000 B.C. when animals and plants were domesticated.
The ________-_______ revolution occurred beginning ___-_____ century.
It allowed _____ people to produce _____ food and _____ the death rate from ________ ________.
This resulted in an _____ ___ in population, which then stabilized due to a later _____ in _____ _____.
The industrial-medical revolution occurred beginning mid-18th century.
It allowed fewer people to produce more food and decreased the death rate from infectious disease.
This resulted in an initial rise in population, which then stabilized due to a later decrease in birth rates.
a change in population that results from an initial decrease in death rate followed by a decrease in birth rates
demographic transition
Declining birth rates associated with demographic transition result from many factors:
better ________
increased access to ________
shift of populations to ________
more ________ working ________ the home
Declining birth rates associated with demographic transition result from many factors:
better education
increased access to contraceptives
shift of populations to cities
more women working outside the home
When the adults of a population have just enough children to replace themselves, the situation is called __________-____ ______ (___).
Because not all children _______ to _____, ___ is slightly higher than __.
When the adults of a population have just enough children to replace themselves, the situation is called replacement-level fertility (RLF).
Because not all children survive to maturity, RLF is slightly higher than 2.
Many developing countries still have _______ _______ populations:
– birth rates _______ _______ death rates
– Children aid in _______ _______
– Limited access to _______
– Even if dropped to RFL, countries like China
will continue growing due to ______ of ______ ______.
Many developing countries still have rapidly growing populations:
– birth rates vastly exceed death rates
– Children aid in family income
– Limited access to contraception
– Even if dropped to RFL, countries like China
will continue growing due to amount of young people.
Population Age Structure:
– ________ according to age groups
– The shape below the peak reveals if the population is ______, ______, or ______
Population Age Structure:
– Distribution according to age groups
– The shape below the peak reveals if the population is expanding, stable, or shrinking
In an age structure that is pyramid-shaped, the population is _________ and _____ RLF.
example: ______
In an age structure that is pyramid-shaped, the population is expanding and above RLF.
example: Mexico
In an age structure that has relatively straight or _________ sides, the population is _____ and __ RLF.
example: _______
In an age structure that has relatively straight or symmetrical sides, the population is stable and at RLF.
example: Sweden
In an age structure that has a narrow base, the population is ______ and _____ RLF.
example: _____
In an age structure that has a narrow base, the population is shrinking and below RLF.
example: Italy
Even if developing countries were to achieve RLF ___________, their population increases would continue for _______.
Even if developing countries were to achieve RLF immediately, their population increases would continue for decades.
U.S. population is fastest growing of all industrial nations:
U.S. fertility rate is only approx. ___, _____ RLF
However, ________ is adding people rapidly and ________ remains higher than in other nations
U.S. population is fastest growing of all industrial nations:
U.S. fertility rate is only approx. 2.0, below RLF
However, immigration is adding people rapidly and survivorship remains higher than in other nations
Growth of the U.S. has serious implications for the environment of the U.S. and the Earth:
Americans consume ___ ____ ______ and produce ___ ____ ________ than the global average
The ________ ________ is more than ___ times greater for U.S. residents than the global average
Growth of the U.S. has serious implications for the environment of the U.S. and the Earth:
Americans consume far more resources and produce far more pollution than the global average
The ecological footprint is more than 2.5 times greater for U.S. residents than the global average
_______ (nerve cells) must perform four specialized functions:
– _______ information
– _______ information
– _______ _______ over distances
– _______ _______ to other neurons, tissues, or organs
Neurons (nerve cells) must perform four specialized functions:
– Receive information
– Integrate information
– Conduct signals over distances
– Transmit signals to other neurons, tissues, or organs
Typical neurons have four distinct structural regions
_______
_______
_______
_______
Typical neurons have four distinct structural regions
- *dendrites**
- *cell** body
- *axon**
- *synaptic** terminals
_______ are branched cell body extensions that _______ _______ from surrounding neurons and sensory receptors.
Dendrites are branched cell body extensions that receive information from surrounding neurons and sensory receptors.
The cell body _______ incoming information from _______; if incoming signals are _______ enough, an _______ _______ (electrical output signal) forms.
The cell body integrates incoming information from dendrites; if incoming signals are positive enough, an action potential (electrical output signal) forms.
The ____ conducts electrical signals to the _______ _______, is often covered in _______ to speed electric transmission, and is often _______ _______ to form nerves.
The axon conducts electrical signals to the synaptic terminal, is often covered in myelin to speed electric transmission, and is often bundled together to form nerves.
The ______ ______ is the branched endings of axons.
Most contain _______________, specific chemicals released under the stimulus of an action potential.
Forms _______ with other cells - the site at which the neuron communicates with other _____, _______, or _______.
The synaptic terminal is the branched endings of axons.
Most contain neurotransmitters, specific chemicals released under the stimulus of an action potential.
Forms synapses with other cells - the site at which the neuron communicates with other cells, tissues, or organs.
Neural activity occurs when _______ produce _______ _______ across their _______.
Neural activity occurs when neurons produce electrical voltages across their membranes.
Most neurons have a negative resting potential:
– Describes the resting ______ ______ ______
– Ranges from ___ to ___ millivolts (mV)
– Negative value indicates that the ____ ______ is more negative than the ______
Most neurons have a negative resting potential:
– Describes the resting neuron membrane potential
– Ranges from -40 to -90 millivolts (mV)
– Negative value indicates that the cell interior is more negative than the exterior
If the neuron membrane potential becomes less negative, reaching a ______ ______, the neuron will generate an ______ ______.
If the neuron membrane potential becomes less negative, reaching a threshold value, the neuron will generate an action potential.
______ ______ is when the neuron membrane potential rises rapidly to +50 mV, then returns to ______ ______.
The action potential signal flows down ____ to ______ ______, where cell communication occurs.
Action potential is when the neuron membrane potential rises rapidly to +50 mV, then returns to resting potential.
The action potential signal flows down axons to synaptic terminals, where cell communication occurs.
Neurons communicate at _______.
- The _______ neuron transmits a signal by releasing _____________ molecules from _______ into the _______ gap.
- The _______ neuron has specialized _______ molecules which bind to the _____________ and cause _______ in the cell.
Neurons communicate at synapses.
- The presynaptic neuron transmits a signal by releasing neurotransmitter molecules from vesicles into the synaptic gap.
- The postsynaptic neuron has specialized receptor molecules which bind to the neurotransmitter and cause changes in the cell.
When ________ neuron receptors bind to neurotransmitters, specific ____ ______ open and allow ion flow across the cell membrane, which causes a brief change in membrane potential (________ ________, or ____).
When postsynaptic neuron receptors bind to neurotransmitters, specific ion channels open and allow ion flow across the cell membrane, which causes a brief change in membrane potential (postsynaptic potential, or PSP).
________ postsynaptic potentials (EPSPs)
–Make the neuron ____ negative inside
–The membrane potential gets ______ ____ threshold potential
–And is ____ likely to form an action potential
– Can occur when ___ ______ open,
allowing ___ into the cell
Excitatory postsynaptic potentials (EPSPs)
– Make the neuron less negative inside
– The membrane potential gets closer to threshold potential
– And is more likely to form an action potential
– Can occur when Na+ channels open,
allowing Na+ into the cell
________ postsynaptic potentials (IPSPs)
—Make the neuron ____ negative inside
—The membrane potential gets ______ ______
threshold potential
—And is ____ likely to form an action potential
—Can occur when ___ _______ open,
allowing ___ ____ of the cell
Inhibitory postsynaptic potentials (IPSPs)
—Make the neuron more negative inside
—The membrane potential gets further from
threshold potential
—And is less likely to form an action potential
—Can occur when K+ channels open,
allowing K+ out of the cell
Individually, PSPs are weak
and cannot stimulate an _____ _______.
_______ & a ____ ____ receive many EPSPs and IPSPs.
_______ of PSPs occurs – if threshold is reached, an
_______ _______ forms.
Individually, PSPs are weak
and cannot stimulate an action potential.
Dendrites & a cell body receive many EPSPs and IPSPs.
Summation of PSPs occurs – if threshold is reached, an
action potential forms.
Information processing requires four basic operations:
_______ ____ of stimulus
_______ _______ of stimulus
_______ information (_______)
_______ the response (_______)
Information processing requires four basic operations:
Determine type of stimulus
Signal intensity of stimulus
Integrate information (convergence)
Direct the response (divergence)
Nervous systems determine the type of stimulus based on ______ ______ in the brain - ______ parts of the brain perceive _______ _______ when stimulated.
Nervous systems determine the type of stimulus based on wiring patterns in the brain - specific parts of the brain perceive specific senses when stimulated.
Stimulus intensity is coded by the frequency of _____ _______ and the _____ of _____ that are involved.
Stimulus intensity is coded by the frequency of action potentials and the number of neurons that are involved.
Neurons _______ information from many sources and process through _______:
_____ neurons funnel their signals to _____ neurons,
_______ occurs in these neurons and appropriate _______ are formed.
Neurons integrate information from many sources and process through convergence:
many neurons funnel their signals to fewer neurons,
summation occurs in these neurons and appropriate responses are formed.
Neurons initiate and direct complex responses via _______:
a few ______-______ neurons stimulate _____ neurons that control _______ and _______.
Neurons initiate and direct complex responses via divergence:
a few decision-making neurons stimulate many neurons that control muscles and glands.
Most neural pathways contain four elements:
– _______ neurons
– _______ neurons
– _______ neutrons
– _______
Most neural pathways contain four elements:
– Sensory neurons
– Association neurons
– Motor neutrons
– Effectors
______ ______ receive information from the internal or external environment.
Sensory neurons receive information from the internal or external environment.
__________ _______ integrate information from many different sources and activate motor neurons.
Association neurons integrate information from many different sources and activate motor neurons.
_____ ______ receive instructions from association neurons and activate muscles or glands.
Motor neurons receive instructions from association neurons and activate muscles or glands.
_______ are muscles or glands that perform the desired response.
Effectors are muscles or glands that perform the desired response.
