Responses to Environment
This term describes any observable action an organism performs in response to internal or external stimuli.
What is behavior?
These organisms form the base of all food webs by converting sunlight or chemical energy into usable biological energy.
What are primary producers (autotrophs)?
This term refers to the number of individuals of a species per unit area.
What is population density?
An interaction in which both species benefit, such as bees pollinating flowers while obtaining nectar.
What is mutualism?
This measure reflects both the number of species and their relative abundance in a community.
What is species diversity?
A genetically programmed, instinctive sequence of behaviors triggered by a specific stimulus, such as a male stickleback attacking a red object.
What is a fixed action pattern?
Only about this percentage of energy is transferred from one trophic level to the next.
What is 10%?
A population growing under ideal conditions with unlimited resources will show this type of growth curve.
What is exponential growth? or J curve
This principle states that two species competing for the same niche cannot coexist indefinitely.
What is the competitive exclusion principle?
A disturbance that removes life and soil entirely, such as a volcanic eruption, leads to this type of succession.
What is primary succession?
This type of learning occurs during a critical period early in life and is often irreversible, as shown in Lorenz’s gosling experiments.
What is imprinting?
This measures the total amount of energy captured by producers through photosynthesis before respiration occurs.
What is gross primary production (GPP)?
This type of survivorship curve is characterized by high early mortality and few individuals reaching adulthood.
What is a Type III survivorship curve?
A species that has a disproportionately large effect on its community relative to its abundance, such as sea otters in kelp forests.
What is a keystone species?
This index is commonly used to quantify biodiversity by accounting for species richness and evenness.
What is Simpson’s Diversity Index?
A directed movement toward or away from a stimulus, such as moths flying toward light or bacteria moving toward nutrients.
What is taxis?
Energy that remains available to consumers after producers use some energy for cellular respiration.
What is net primary production (NPP)?
The maximum population size an environment can sustain indefinitely is known as this.
What is carrying capacity (K)?
When two harmful species evolve to resemble each other to reinforce predator avoidance, this type of mimicry is occurring.
What is Müllerian mimicry?
Non-native species that spread rapidly and outcompete native species, reducing biodiversity, fall under this category.
What are invasive species?
This evolutionary explanation explains why a behavior exists because it increases survival or reproductive success.
What is an ultimate cause?
Unlike energy, this cycles through ecosystems in processes such as the carbon, nitrogen, and phosphorus cycles.
What is matter? or nutrients
This population growth model accounts for limiting resources and slowing growth as population size approaches carrying capacity.
What is logistic growth? or S-curve
An ecological process where changes at one trophic level cause indirect effects at other levels, often starting with predator removal or reintroduction.
What is a trophic cascade?
Ecosystems with higher biodiversity are more stable because multiple species can perform similar ecological roles, a concept known as this.
What is ecosystem resilience?