Unit 8: Ecology

AP Biology | 2024-2025

What are endotherms?

animals that generate their own body heat through metabolism

What are ectotherms?

animals that lack an internal mechanism to control body temperatures

What is instinct?

an inborn, unlearned behavior

What is learning?

a change in a behavior brought about by an experience

What is imprinting?

the process in which an offspring will accept the first moving object they see as their mother if their real mother is absent

What is a critical period?

a window of time when the animal is sensitive to certain aspects of the environment

What is habituation?

when an animal learns not to respond to a stimulus

What are circadian rhythms?

the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle

What are pheromones?

chemical signals between members of the same species that stimulate olfactor receptors and ultimately affect behavior

What is agnostic behavior?

aggressive behavior that occurs as a result of competition for food and other resources

What are dominance hierarchies?

when members in a group have established which members are the dominant

Wha is teritoriality?

the behavior of organisms that defend a specific area to ensure access to resources like food, mates, and shelter

What is altruistic behavior?

unselfish behavior that benefits another organism in the group at the individual’s expense because it advances the genes of the group

What are the three types of symbiotic relationships?

mutualism, commensalism, and parasitism

What is mutualism?

when both organisms benefit

What is commensalism?

when one organism lives off another with no harm to the host

What is parasitism?

when the organism harms its host

What is photoperiodism?

when plants flower in response to changes in the amount of daylight and darkness they receive

What is tropism?

a directional growth response of a plant towards or away from an external stimulus

What is phototropism?

the way plants respond to sunlight

What is gravitropism?

the way plants respond to gravity

What is thigmotropism?

the way plants respond to touch

What is ecology?

the study of interactions between living things and their environments

What is the biopshere?

the entire part of the Earth where living things exist

What is an ecosystem?

a community of living organisms (biotic factors) interacting with their non-living physical environment (abotic factors) within a specific area

What is a community?

a group of populations interacting in the same area

What is a population?

a group of individuals that belong to the same species and are interbreeding

What is primary productivity?

the rate at which energy from sunlight is converted into organic matter by photosynthetic organisms within an ecosystem

What is gross productivity?

the total rate at which primary producers capture energy from sunlight through photosynthesis

What is net productivity?

the rate at which plants store energy as biomass after subtracting the energy used for their own respiration

What are keystone species?

organisms particularly important to their ecosystem

What is the 10% rule

in a food chain, only about 10% of energy is transferred from one level to the next

What can be represented in an ecological pyramid?

energy flow, biomass, and the number of members within an ecosystem

What is population growth?

the number of births minus the number of deaths divided by the size of the population

What is carrying capacity?

the maximum number of individuals of a species that a habitat can support

When does exponential growth of a population occur?

when it is in an ideal environment

What is ecological succession?

the predictable procession of plant communities over a relatively short period of time (decades or centuries)

What is primary succession?

the process of ecological succession in which no previous organisms have existed

What is the proximate question that behavioral ecologists study?

how the behavior occurs

What is the ultimate question that behavior ecologists study?

why the behavior occurs

What is ethology?

the study of how organisms behave

What is insight learning?

“ah-ha moment”; the sudden discovery of the correct solution following incorrect attempts based on trial and error

What is fixed action pattern?

a sequence of instinctive behaviors triggered by a specific stimulus.

What is classical conditioning?

a learning process where a neutral stimulus becomes associated with a meaningful stimulus, eliciting a conditioned response.

What is operant conditioning?

a learning process where behaviors are modified through rewards or punishments.

What is kinesis?

a movement or activity of an organism in response to a stimulus that is not directional

What is taxis?

the automatic movement of an organism toward or away from a stimulus

What is population density?

the number of individuals of a species per unit area or volume

What is population dispersion?

the pattern of spacing among individuals within boundaries of a population

What is clumped dispersion?

a type of population dispersion where individuals are grouped together in clusters or patches, often due to resource availability or social behavior.

What is uniform dispersion?

a type of population dispersion where individuals are evenly spaced across a given area, often resulting from competition for resources.

What is random dispersion?

a type of population dispersion where individuals are spaced unpredictably, without a discernible pattern, often occurring in environments where resources are uniformly available.

What is demography?

the study of populations, including their size, distribution, density, and growth patterns.

ex: birth and death rates

What is a life table?

a table that shows the survival and mortality rates of a population at each age interval, used to analyze demographic data and predict future population trends

What is a survivorship curve?

a graph that represents the number of individuals surviving at each age for a given species, illustrating patterns of mortality and longevity

What is a reproductive table?

a table that summarizes the reproductive rates of individuals in a population, showing age-specific birth rates and helping to predict future population growth

What is semelparity?

a reproductive strategy characterized by a single, large reproductive event followed by death, often seen in species with high mortality rates.

What is iteoparity?

a reproductive strategy involving multiple reproductive events throughout an individual's life, allowing for the production of offspring over time