lab exam 2 Flashcards
(164 cards)
1
Q
ecologcial niche
A
describes a species’ functional role and position within its environment
2
Q
abiotic interactions
A
non-living components of an environment and their effects on living organisms
3
Q
biotic interactions
A
living components of an environment and their effects on living organisms
4
Q
competitive exclusion
A
two species competing for the same limited resources cannot coexist in the same niche indefinitely
5
Q
limiting resource
A
any factor that restricts the growth or survival of a population
6
Q
fundamental niche
A
set of conditions under which an animal (can survive and reproduce itself
7
Q
realized niche
A
occupies due to interactions with other species
8
Q
compare and contrast fundamental and realized niche
A
Comparison:
Both describe the environmental conditions where a species lives and survives.
Contrast:
Fundamental niche = ideal conditions (no competition).
Realized niche = actual conditions (with competition and other pressures).
9
Q
what factors make up an ecological niche?
A
Habitat:
Resource Use
Behavior
Abiotic Factors
Biotic Interactions
Role in the Ecosystem
10
Q
how is that 2 species can coexist in the same niche?
A
resource partitioning
11
Q
What happens to an organisms’s ability to occupy its niche if there is no competition for a limiting resource?
A
The organism can fully occupy its fundamental niche.
It has access to more resources and more space.
Its population size may increase.
12
Q
What is the principle of competitive exclusion?
A
two species with identical ecological niches cannot coexist indefinitely when competing for the same limited resources
12
Q
What occurs when there is competition for a limiting resource?
A
Species compete for the same scarce resource (like food, water, or space).
An organism’s realized niche shrinks
Competitive exclusion may occur
13
Q
How does copetitive exclusion influences survivial of species in a habitat?
A
One species outcompetes another for a critical resource.
The weaker species may be forced to move, adapt, or die out.
Leads to reduced biodiversity if species can’t coexist.
14
Q
Ethogram
A
a comprehensive inventory or catalog of the behaviors displayed by a specific species
15
Q
Focal sampling/follows
A
observing and recording the behavior of a single individual or a group of individuals for a specific period of time
16
Q
all occurences sampling
A
observing and recording the frequency of specific behaviors within a defined time period
17
Q
scan samplaing
A
researchers record the behavior of a group of individuals at specific, predetermined intervals
18
Q
agnostic behavior
A
social interactions and behaviors related to fighting
19
Q
foraging behavior
A
process by which animals find, obtain, and consume food resources
19
Q
mating behavior
A
process by which animals find, obtain, and consume food resources
20
Q
mate choice
A
the non-random selection of a mate by one sex, based on specific traits of the other sex
21
Q
Behavioral event
A
A specific, observable action performed by an organism in response to a stimulus
22
Q
Ad llibitum
A
a feeding regimen where animals have free access to food and water,
23
Dominance hierachies
a social structure within a group where individuals are ranked by dominance
24
what types of behavior can be catergorized in an ethogram
Feeding Behavior
Social Behavior
Locomotion Behavior
Resting Behavior
25
why do researchers use ethograms?
Organize and define behaviors clearly for study.
Quantify behavior — measure how often and how long behaviors happen.
25
What type of sampling techniques are being used in a behavioral experiment?
Focal Animal Sampling:
Watch one individual closely for a set time and record all its behaviors.
Scan Sampling:
Look at a whole group at regular intervals
Behavior Sampling:
Record a specific behavior whenever it happens, no matter which animal does it.
26
How are behavioral evets observed and recorded?
1. observation
2.define behavior
3.choose a sampling technique
4.recording the data
5.time tracking
6.coding behaviors
7.analyze the data
27
birth rate
of babies born in a nation
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carrying capacity
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death rate
of ppl who died in a nation
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environement
the surroundings or conditions in which a person, animal, or plant lives or operates
31
fertility
the natural ability to conceive and bear offspring
31
instantaneous rate of change
the rate at which the function's value changes at that exact moment
32
intrinstic growth rate
the maximum theoretical rate at which a population can increase under ideal conditions, where there are no limiting environmental factors
32
logistic growth
population's per capita growth rate gets smaller and smaller as population size approaches r imposed by limited resources in the environment
33
per capita growth rate
a measure of how much a population is growing per individual
33
population
ll the organisms of the same species living in a specific area and capable of interbreeding
34
population growth rate
the change in the number of individuals in a population over a specific period of time
35
population model
a mathematical representation of how a population's size and characteristics change over time
36
resource
any substance or object in the environment that an organism needs for survival, growth, and reproduction
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species
a group of organisms that can interbreed naturally and produce fertile offspring
36
stable population size
a situation where the population's size remains relatively constant over time, with birth and death rates balanced
37
Why are growth models useful?
Simplify complex systems into understandable patterns
Predict future behavior based on current trends
Identify key factors that influence growth
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How population growth models are used to study populations?
Track and predict population size changes
Identify growth limits and key factors
Compare real data to theoretical patterns
38
How does resource limitation affect population growth?
Slows population growth as resources become scarce
Causes competition among individuals
39
Can a population growth exponentially if it uses a limiting resource?
NO
39
How does resource limitation affect logistic and exponential growth of a pop?
Exponential: Growth eventually stops but model ignores limits.
Logistic: Growth slows as population nears carrying capacity.
40
Example of how population growth models are used to describe the growth of a pop. over time
Bacteria in a lab: Initially grow exponentially with unlimited nutrients, then slow and level off as resources run out, following a logistic growth pattern.
41
Why does an increase in r lead to more idv, over time than an equal increase in N0 would?
Increase in r (growth rate):leading to exponential increases in the population over time.
Increase in N₀ (initial population size): While a larger N₀ starts the population off higher, r determines how quickly the population increases, so a higher r leads to more individuals over time.
42
How is intristic growth rate diff. than the instantaneous rate of change?
Intrinsic growth rate (r): Maximum growth rate under ideal conditions.
Instantaneous rate of change: Actual growth rate at a specific moment
43
How does resource limitation affect carrying capaciy?
Resource limitation sets the carrying capacity
43
How would K for a population change?
Environmental changes
Depletion of resources
Species interactions
43
what is the relationship btw the growth rate, birth rate & death rate for a pop.?
Growth rate = Birth rate - Death rate
44
Neurons
nerve cells that send messages all over your body to allow you to do everything
45
Action Potential
a rapid sequence of changes in the voltage across a membrane
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Neurotransmitter
chemical messengers that facilitate communication between neurons and other cells in the body
47
Senses
body perceives an external stimulus
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Stimulus
a thing or event that evokes a specific functional reaction
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Nociceptors
a sensory receptor for painful stimuli.
49
axon
portion of a nerve cell (neuron) that carries nerve impulses away from the cell body
50
dendrites
the receiving or input portions of a neuron
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soma
The central part of a neuron or other cell containing the nucleus
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synapse
asymmetric intercellular junctions that mediate rapid point-to-point communication between neurons
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synaptic connections
the contact between the presynaptic and postsynaptic neuron
54
receptive field
specific area or set of stimuli that a sensory neuron or a group of neurons responds to
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membrane potential
electrical charge difference across a cell membrane
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Vm
membrane potential
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threshold potential
the critical level to which a membrane potential must be depolarized to initiate an action potential
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botulinum toxin
a powerful neurotoxin produced by the bacterium Clostridium botulinum
56
Resting potential
when the cell is in a non-excited state
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ions
atom or molecule that has gained or lost electrons
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lidocaine
local anesthetics
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membranes
thin layer that forms the outer boundary of a living cell or of an internal cell compartment
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neurotoxins
substances that are poisonous to nerve tissue
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ion channels
proteins embedded in the cell membrane that allow ions to pass in and out of cell
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Na+ channels
ion channel that specifically allow the flow of sodium ions (Na⁺) into or out of a cell.
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Diffusion
movement of molecules from an area of high concentration --> low concentration
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Depolarized
reduce or remove the polarization of
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K+ channels
ion channels that allow the flow of potassium ions (K⁺) across the cell membrane
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Hyperolarized
produce an increase in potential difference across
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Na+/K+ ion pump
a crucial protein within cell membranes that actively transports sodium ions (Na+) out of the cell and potassium ions (K+) into the cell
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transduction
conversion of energy or a stimulus from one form to another
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channels
facilitate the transport of specific molecules across the membrane
67
voltage-gated ion channels
membrane proteins that respond to changes in membrane potential,
68
how does an action potential travel from a pain stimulus to the brain?
through specialized nerve fibers (nociceptors) that sense pain --> spinal cord --> brain's thalamus and somatosensory cortex.
69
How is threshold stimulus in neuronal communication?
the minimum level of stimulation needed to open voltage-gated ion channels and start an action potential
69
What is occuring in a neuron when it is depolarized?
neuron's inside becomes less negative (more positive) because sodium (Na⁺) ions rush into the cell.
69
describe which ions are involved & the direction of their movement across the neuronal membrane
Sodium ions (Na⁺) move into the neuron.
potassium ions (K⁺) move out of the neuron.
69
WHat occurs at the synapse btw a muscle and a motor neutorn?
The motor neuron releases acetylcholine (ACh).
ACh binds to receptors on the muscle cell membrane.
This triggers muscle cell depolarization and starts a muscle contraction.
69
What is occuring in the neuron when threshold is reached?
Voltage-gated Na⁺ channels open-->Na⁺ floods into the neuron,
causing a rapid depolarization and starting an action potential.
70
How does the intensity of a stimulus affect the transmission of an action potential?
affects the frequency of action potentials-->more frequent action potentials
71
How does the intensity of the stimulus affect the interaction btw a muscle cell & a motor neuron?
activates more motor neurons and muscle fiber --> causing a stronger muscle contraction.
72
HOw do different neurotoxins affect neural signaling?
Blocking ion channels
Overstimulating receptors
Preventing neurotransmitter release
73
How is a neuron's membrane potential established?
Na⁺/K⁺ pumps (push 3 Na⁺ out, 2 K⁺ in)
K⁺ leak channels (let K⁺ flow out)
making the inside more negative than the outside
74
What ions are involved in membrane potential?
Sodium (Na⁺)
Potassium (K⁺)
Chloride (Cl⁻)
Calcium (Ca²⁺)
74
how are ions distrubted across a membrane at rest
Inside the neuron:
--High concentration of K⁺ (potassium)
--Low concentration of Na⁺ (sodium)
--Some Cl⁻ (chloride)
Outside the neuron:
--High concentration of Na⁺
--Low concentration of K⁺
--Some Ca²⁺ (calcium)
74
When there is an action potential, what ion channels are involved?
Voltage-gated Na⁺ channels
Voltage-gated K⁺ channels
74
How & when do ion channels open and close?
Voltage-gated Na⁺ channels:
--Open when the membrane depolarizes to the threshold, allowing Na⁺ to rush in.
--Close shortly after, during repolarization, due to inactivation.
Voltage-gated K⁺ channels:
--Open when the membrane depolarizes, allowing K⁺ to exit and repolarize the neuron.
--Close as the membrane potential returns to resting potential.
75
What type of process is involved in the movement of ions across a neuron's membrane?
Passive transport
--Diffusion through ion channels
--Facilitated diffusion
Active transport
--Na⁺/K⁺ pump
76
Crepuscular
the study of organisms that are most active during twilight
77
Succession
progressive change in the species composition of an ecological community over time
78
Per capita
per individual
79
Exponential v. logistical growth
Exponential Growth:
Unrestricted growth, J-shaped curve.
Logistic Growth:
Growth slows as population approaches carrying capacity, S-shaped curve.
80
population oscillation
repeating rises and drops in the size of the population over time.
81
paradox of enrichment
idea that increasing resources for a prey population can lead to instability or population crashes in predator-prey systems
82
alternative hypothsis
proposes that there is a relationship or difference between the variables being studied.
83
null hypothesis
a statistical theory suggesting that no statistical relationship exists between given observed variables
84
t-test
test of a statistical significant difference between two groups
85
what is carrying capacity?
maximum # of individuals an environment can support sustainably
86
what happens to population growth as the pop. nears carrying capacity?
slows down then levels off
87
describe how the pop. of prey would be diff. on an island w/ or w/o predators
With predators: prey population is smaller, fluctuates.
Without predators: prey population grows rapidly.
88
What would happen to the predator-prey interactions on an island if it suddenly had an influx of additional prey species.
More prey = more food for predators, leading to higher predator numbers and fluctuating prey populations.
89
what are the characteristics of each type of growth?
Exponential growth:
--Unrestricted, rapid growth
--J-shaped curve
--No limits on resources
Logistic growth:
--Growth slows as population nears carrying capacity
--S-shaped curve
--Limited resources.
90
how would growth rates change in predatory & prey species when the abundance of plant life is also take into consideration?
More plants = higher prey growth, leading to potential rise in predator numbers, but growth stabilizes over time.
91
community
interacting group of various species in a common location
92
trophic levels
position it occupies in a food web
93
primary producers v. consumer
Primary producers: Organisms that produce their own food via photosynthesis or chemosynthesis.
Consumers: Organisms that eat other organisms
94
filter feeders
organism that obtains its food by filtering out tiny particles or organisms from a current of water
95
sessile v. mobile
Sessile: Organisms that are fixed in one place (barnacles).
Mobile: Organisms that can move freely ( fish).
96
biomass
total mass of living organisms in a given area or volume at a specific time
97
population size
total # of individuals within a specific group or area
98
index
be used to quantify and compare the characteristics of different species, populations, or ecosystems
99
competition
rivalry between organisms
100
predation
a biological interaction where one organism, the predator, kills and eats another organism, its prey
100
dominance
the relationship between two versions of a gene
101
competitive
a relationship between organisms where they strive for the same limited resources, leading to a negative impact on both species
102
hierarchy
systemic organisation of organisms into levels
102
effects of predation
Controls prey populations
preventing overpopulation.
Influences prey behavior and distribution.
Can drive evolution
103
food chain v. food web
-Food chain: A linear sequence of organisms where each is eaten by the next (e.g., plant → herbivore → carnivore).
Food web: A complex network of interconnected food chains in an ecosystem, showing multiple feeding relationships.
103
dominant v. keystone species
Dominant species: The most abundant or impactful species in an ecosystem, often shaping its structure (e.g., trees in a forest).
Keystone species: A species that has a disproportionately large effect on its ecosystem, often maintaining its structure (e.g., wolves in Yellowstone).
104
community structure
composition of a community, encompassing the number and relative abundance of species within it
105
invasive species
a non-native organism that causes harm to an environment where it is not native
106
how do keystone species affect community structure?
maintain community structure by controlling populations & supporting biodiversity
107
describe the roles of the species in the intertidal zone.
Primary producers (like algae)
Herbivores (like snails)
Predators (like sea stars)
Filter feeders (like mussels)
Decomposers (like bacteria)
108
Algae
Simple, plant-like organisms, making energy through photosynthesis in water
109
describe the roles of organism in the diff. trophic levels of a food chain/web?
Producers: Make energy
Primary consumers: Eat producers (herbivores)
Secondary consumers: Eat primary consumers (small carnivores)
Tertiary consumers: Eat secondary consumers (top predators)
Decomposers
110
Can organism occupy more than one trophic levels?
Yes
111
biomolecule
a chemical compound found in living organisms
112
algal bloom
a rapid increase in the population of algae in a body of water
113
chlorophyll
a pigment that gives plants their green color
114
cyanobacteria
photosynthetic microscopic organisms that are technically bacteria
115
cyanotoxin
harmful toxins produced by cyanobacteria
116
direct effect
When one species directly impacts another without intermediaries
ex. a predator eating prey
117
dissolved oxygen
the amount of oxygen gas that is physically dissolved in water
118
eutrophication
Excess nutrients (like nitrogen and phosphorus) cause overgrowth of algae, leading to oxygen loss and death of aquatic life
119
indirect effect
When one species impacts another through a third species
ex. predators reduce herbivores
120
microcystins
a family of toxins produced by species of freshwater cyanobacteria
121
nitrogen fixation
Process where bacteria convert atmospheric nitrogen (N₂) into usable forms like ammonia (NH₃) for plants.
122
nutrient
essential chemical substances that organisms require for growth, maintenance, and reproduction
123
nutrient pollution
too much nitrogen or phosphorus enters ecosystems, causing problems like algal blooms and dead zones.
124
photosynthesis
use sunlight to make food (glucose) from carbon dioxide and water, releasing oxygen.
125
phytoplankton
microscopic marine algae
126
zooplankton
small animals in the planktonic community
127
role of consumers in an ecosystem
-Herbivores
-Carnivores
-Omnivores
They transfer energy through the food chain and help control populations.
128
what role do cyanobacteria play in an ecosystem?
-acting as primary producer
-performing nitrogen fixation
-contributing to oxygen production
128
what are the diff. types of consumers found in an ecosystem?
Primary consumers
Secondary consumers
Tertiary consumers
Omnivores
Decomposers
129
what does it mean for nutrients to be limiting?
limit the growth or productivity of organisms
130
how does increased availability of limiting nutrients affect lake ecosystem?
More limiting nutrients = excessive algae growth, oxygen depletion, and harm to aquatic life.
131
are limiting nutrients the same for all species?
No
132
what happens to dissolved oxygen when limiting nutrients pollute a lake ecosystem
Nutrient pollution causes algal blooms, depleting dissolved oxygen and harming aquatic life.
133
what are the direct effects of nutrient pollution?
algal blooms
oxygen depletion
death of aquatic organisms.
134
what are the indirect effects of nutrient pollution?
altered food webs
decreased biodiversity
disrupted ecosystem services like water purification
