Ecology Unit Flashcards
Ecology
the scientific study of the interactions between organisms and their environment
what are some examples of biotic factors?
competition, predation, symbioses,
What are some examples of abiotic factors?
temperature, light, water, and nutrients
Species
A population or group of populations whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring,
Population
group of individuals of the same species living in a particular geographic are
community
All of the organisms of different populations that inhabit a particular area.
Ecosystem
All of the abiotic factors in addition to the community of species that exists in a certain area.
What are the two types of ecosystems?
aquatic and terrestrial
Biome
A group of ecosystems that share similar climates and organisms and occupy the same broad geographic area
Biosphere
The global ecosystem-the sum of all of the planet’s ecosystems/all life AND where it lives.
Why are autotrophs so important?
they support all other organisms in the ecosystem
Where must heterotrophs gain their energy from?
other consumers or producers
what are the types of consumers?
primary, secondary, tertiary, and decomposers
What does saprophyte mean?
-phyte means plant sapro- means dead or decaying organic matter
Where do saprophytes get their nutrtion?
nutrients from non-living organic materials such as corpses, fallen plant material, and the wastes of living organisms, and convert them into inorganic forms.
detrivores
similar to decomposers they feed off of non-living organic matter (detritus).
food web
a model representing the feeding relationships within a mecosystems
Niche
the role or function of an organism or a species within an ecosystem
How do trophic levels seperate organisms?
based on their main source of nutrition
Pyramid of Numbers:
Measures population size in trophic levels
pyramid of biomass
measures the amount of dry organic matter in each trophic level
Where does the majority of energy begin in the biosphere and which direction does it flow?
-begins in the sun
-flows in one direction (up)
What is the main source of energy for the water cycle?
the sun!
Carbon/Oxygen Cycle
he relationship between photosynthesis and cellular respiration in the biosphere leads to most sources of release and storage of carbon
Atmospheric deposition
A process of converting nitrgoen into a useful form via chemical process that converts atmospheric nitrogen into ammonia, which is absorbed by organisms.
Nitrogen fixation
process of converting nitrogen into compounds that plants can absorb and use (ammonia)
denitrification
process by which bacteria ( decomposers) convert nitrates ( ammonia derived ) into consumable nitrogen gas
Denitrification is a form of what?
nitrogen fixation via bacteria
Why is phosphorus important?
phosphorus is a major component of many important biomolecules such as nucleic acids, phospholipids, and ATP
Commensalism
ne partner benefits without significantly affecting the other.
Parasitism
one organism (the parasite) harms the host .
Parasitoidism
insects laying eggs on the larva of other insects.
mimicry
resemblance of one organism to another for defense purposes
camouflage
resemblance of an organism to its environment for defense purposes
Habitat
n ecological area inhabited by a particular species of organisms
Competitive Exclusion Principle
two organims with similar needs for the same limiting resources cannot occupy the same niche.
Carrying Capacity
the biotic and abiotic factors of an ecological system determine the number of individuals from a population which the ecosystem can maintain and support
What happens if a population uses resources faster than they can be replaced?
the carrying capacity is reduced, and so is the population
Interspecific Competition:
competition between members of opposing species occupying similar niches
Intraspecific
competition between members of the same species occupying the same niche
What are some population density-dependent factors?
Population Size
Predation
Parasitism
Disease
Stress
Competition
What type of desnity factor is population size?
density-dependent
What type of density factor is predation?
density dependent
What type of desnity factor is parasitism?
density dependent
why type of density factor is disease
dependent
what type of density factor is stress? what about competition?
dependent
What are examples of an density-independent factor?
Natural Disasters
Climate Changes
natality
Birth Rate
invasive species
human introduced(non-native) organism that has negative impacts on an ecological system due to a lack of density dependent limiting factors.
Edge Effect
changes to the abiotic and biotic factors at the boundary of two habitats.
Biomagnification
Retained substances which become more concentrated with each link in the food chain.
Biodiversity
the relative concentration of species in a given area
r-selected organisms
Found in highly variable ecological systems in which population densities fluctuate and there exists little competition.
What are some examples of r-selected organisms?
-rodents, insects,
What are some characteristics of r-selected organisms?
-Short life span
-Small size
-fast population growth rate (reproduce at once and make a lot of offspring)
-variable and unpredicted mortality-
Do r-selected organisms often reach their carrying capacity? Why?
-No, because they have variable and unpredicted mortality, short life spans, and weak competitive ability
K selected organisms?
Found at densities at or near the carrying capacity of an ecological system.
What are some examples of k-selected organisms?
-Large mammals such as humans and elephants
What are some characteristics of k-selected orrganisms?
-large size
-long life span
-reproduce later and life and with fewer offspring, which leads to a slower population growth rate.
-
Why are k-selected organisms found at or near carrying capacity?
- they have strong competitive abilities, and a more constant population since their mortality is predictable ( less fluctuations)
natality:
the number of offspring produced in a certain period of time
Mortality
the number of individuals that die off in a certain period of time
Immigration
Individuals of one species entering a non-native ecological system over a period of time
Emigration
Individuals of one species leaving their native ecological system over a period of time
Ecological extinction
he loss of a species niche within an ecosystem
biological extinction
the complete loss of a species from the biosphere.
how can earth’s systems ( biogeochemical cycles) impact global change?
Both the causes and effects of global change may involve all Earth systems.
Food web
Food Web: ALL the feeding relationships within an ecosystem.
Food chain
a linear sequence of organisms through which nutrients and energy pass as ONE organism eats another
What is the difference between a food web and a food chain?
A food web summarizes ALL the feeding relationships within an ecosystem, while a food chain focus on a linear (ONE WAY) relationship between a few organisms:
Why is photosynthesis included in the water cycle?
because water is a reactant, or input, of photosynthesis.
How many organisms must a food chain consist of?
2+
TRUE OR FALSE: The water cycle encompasses every interaction water has as it cycles through earth’s spheres, whether they impact the cycle or not
TRUE
How do limiting factors relate to population size in logistic growth?
The effects of limiting factors increase as the population increases, which leads it to stabilize at carrying capacity.
Why is the amazon rainforest unique among rainforest biomes?
It produces it’s own rainfall
What element(s) from agricultural fertilizers and industrial pollution are responsible for the proliferation of algae in dead zones?
nitrogen and carbon
What is the purpose of an ecological pyramid?
highlight the nutritional relationships within an ecological system
trophic level
producers and consumers are separated on the ecological pyramid based on their main source of nutrition
Energy(productivity) Pyramid:
the multiplicative loss of energy in an ecological system as it passes from trophic level to trophic level
What is the function of an energy pyramid?
Measures net productivity available to organisms in that trophic level
What leads to precipitation in the hydrologic cycle?
Evaporation and transpiration lead to precipitation in a cycle
Why is nitrogen important?
an essential component of nucleic acids and proteins
denitrification
process by which bacteria ( decomposers) convert nitrates (converted from ammonia) into consumable nitrogen gas
microbiomes
-Microbial communities ( the microorganisms in a particular environment)
What are the biogeochemical cycles?
carbon/oxygen cycle, phosphorus cycle, water cycle, and nitrogen cycle
What is a biogeochemical cycle?
he movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth’s crust
Why is phosphorus important?
major component of many important biomolecules
Exponential Growth-J curve:
predicts unlimited population increase under conditions of unlimited resource
What is the lag phase and what type of growth is it used in?
population growth begins slowly with a small population
-exponential growth
what is the Log Phase and what type of growth is it used in?
Population growth is exponential as conditions are ideal and maximum growth rate can be achieved.
-exponential growth
Iron Law
Populations will increase exponentially because they tend to overproduce while resources will increase linearly, leading to a point of crisis.
What is the point of crisis in the iron law?
- When the population of a species reaches the maximum capacity of the available resources ( the j-curve of the population intersects the linear curve of resources)
-this leads to depletion of resources and population crash?
how do natural resources available in an ecosystem increase?
linearly
Logistic growth-s-curve
Growth pattern that occurs after exponential growth where the population growth slows and stops, leading to a steady population at carrying capacity, due to density-dependent limiting factors
What kind of populations experienceslogistic growth
healthy ones!
what kind of populations experience exponential growth
unsustainable/unhealthy ones, often invasive species.
-leads to a population crash
What causes carrying capacity?
Competition and other limiting factors create a carrying capacity for a population within an ecological system
How often do populations reach their biotic potential?
rarely
Predator Prey Curve
The populations of predator and prey are interdependent of each other
What does a predator prey curve look like?
-as one curve increases, the other decreases, and vice versa
What happens to the carrying capacity if a population uses resources faster than they can be produced?
the carrying capacity of the area will be reduced and the population will crash.
Cellular respiration
the process by which cells derive energy from glucose. The chemical reaction for cellular respiration produces carbon dioxide, water, and energy (ATP) as outputs.
transpiration
the process by which plants give off water vapor through the stomata in their leaves
Interdependence
THe survival of a species is dependent on other living organisms and nonliving components.
Form determines function
most if not all of the shape, size, and structure of the organism aids the organism in survival in some way
Where is the theme of form determines function often seen?
mutualism and coevolution
Homeostasis
any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival
How does the movement of matter compare to the movement of energy?
Energy flows in one direction, while matter cycles.
Levels of organization
structures in nature, frequently identified by part-whole relationships, with things at higher levels being composed of things at the next lower leve
coninuity and change
how genetic information is carried forward and changes
Unity within diversity
the idea that all living organisms, despite their vast diversity, share certain fundamental characteristics that point to a common ancestry.
evolution by means of natural selection
“survival of the fittest”-Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success.
what are the Characteristics of Life
Living things are based on a universal genetic code.
Living things grow and develop.
Living things respond to their environment.
Living things reproduce.
Living things maintain a stable internal environment.
Living things obtain and use energy.
Living things are made up of cells.
Taken as a group, living things evolve.
What are the phases of logistic growth?
1-population growth increases/log phase
2-population growth decreases
3-growth stops as it reaches carrying capacity
population density
the concentration of individuals of a particular species within a certain area
Geographic range
the places that a certain species occupies
What directly affects the size and distribution of plant populations?
herbivory
What is most likely to occur if an organism’s ecosystem is outside its tolerance range?
It will fail to reproduce
tolerance
ability of an organism to survive and reproduce under suboptimal circumstances
What are the three methods of ecological study?
observation, modeling, and experimentation
What are the differences between detritivores and decomposers+ examples
Decomposers feed by breaking down organic matter, while detritivores chew or grind detritus (dead organisms and wastes) and the decomposers inside them.
-earthworm is a detritivore, bacteria is a decomposer
