Unit 8 Ecology Study Guide Flashcards

A complete set of vocabulary flashcards covering concepts from the Unit 8 Ecology study guide, including animal behavior, energy flow, biogeochemical cycles, population dynamics, community ecology, and disruptions.

Innate Behavior

Behavior that is hardwired in an organism's genes and comes from heredity, such as instincts like bird migration routes.

Learned Behavior

Behavior acquired through observing other animals and from life experiences, such as ducklings learning to avoid danger by following their mother.

Visual Cue

A form of animal communication using light patterns to attract each other for mating, such as specific flash patterns in fireflies.

Auditory Cue

A form of animal communication using sound, such as clownfish producing popping, clicking, chirping, or hydrodynamic sounds to warn of predators.

Chemical Cue

A form of animal communication using chemical signals, such as comforting pheromones released from a cat's cheeks when rubbing against someone.

Tactile Cue

A form of animal communication involving physical touch, such as monkeys and apes picking bugs off each other for grooming and affection.

Cooperative Behavior

The process where groups of organisms work together for common or mutual benefits, leading to increased individual survival and evolutionary fitness.

Endotherm

An organism that uses thermal energy generated by metabolism to maintain homeostatic body temperatures.

Ectotherm

An organism that lacks efficient internal mechanisms for maintaining body temperature and regulates temperature behaviorally.

Metabolic Rate and Body Mass Relationship

The inverse relationship between metabolic rate per unit body mass and organism size, where smaller multicellular organisms generally have higher metabolic rates.

Biomass

Energy stored as part of organisms' bodies when energy enters a trophic level.

10% Rule

The ecological rule of thumb stating that approximately $10\%$ of energy is transferred from one trophic level to the next.

Decomposers

Organisms that break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers.

Photosynthetic Organisms

Autotrophs that capture energy present in sunlight to produce organic molecules.

Chemosynthetic Organisms

Autotrophs that capture energy from small inorganic molecules in their environment without requiring oxygen.

Condensation

The process where water vapor in the atmosphere cools, changing from a gaseous state to liquid water droplets to form clouds, fog, and dew.

Precipitation

Any form of water—such as rain, snow, hail, or sleet—that falls from the atmosphere to Earth's surface.

Evaporation

The process where liquid water turns into water vapor and rises into the atmosphere.

Transpiration

The process where plants absorb water through their roots and release it as water vapor into the atmosphere from their leaves.

Combustion

The burning of organic materials like wood or fossil fuels, releasing carbon dioxide ($\text{CO}_2$) into the atmosphere.

Cellular Respiration

The metabolic process in cells that breaks carbohydrate bonds to release energy, releasing carbon dioxide as a byproduct.

Ammonification

The process where nitrogenous waste or remains of dead animals are converted into ammonium ($\text{NH}_4^+$) by bacteria and fungi.

Nitrification

The process where ammonium ($\text{NH}_4^+$) is converted to nitrites ($\text{NO}_2^-$) and then into nitrates ($\text{NO}_3^-$) by nitrifying bacteria.

Assimilation

The process where plants and animals absorb and incorporate fixed nitrogen compounds into biological molecules like proteins and DNA.

Denitrification

The process where bacteria convert nitrates into nitrogen gas ($\text{N}_2$), allowing it to re-enter the atmosphere.

Nitrogen Fixation

The process of converting atmospheric nitrogen gas ($\text{N}_2$) into ammonia ($\text{NH}_3$) by nitrogen-fixing bacteria.

Conspecifics

Organisms that are all members of the same species.

Heterospecifics

Organisms that are members of different species.

Biotic Factors

Living components or factors within an ecosystem.

Abiotic Factors

Non-living components or factors within an ecosystem.

Uniform Dispersion Pattern

A pattern where individuals are equally spaced, such as apple trees in a field planted to allow uncompetitive access to sunlight and nutrients.

Random Dispersion Pattern

A pattern where individuals are distributed unpredictably, such as dandelions originating from wind-dispersed seeds.

Clumped Dispersion Pattern

A pattern where individuals aggregate in groups, such as penguins huddling together for warmth and protection.

Exponential Population Growth

Population growth in which the number of individuals in a population increases drastically at a constant rate over time under ideal conditions.

Carrying Capacity ($K$)

The maximum population size an environment can support due to limited resources and limiting factors.

Logistic Population Growth

A model of population growth that incorporates carrying capacity ($K$), slowing growth as resources become limited.

Intraspecific Competition

Competition occurring between members of the same species, such as two male mice competing for mates.

Interspecific Competition

Competition occurring between members of different species, such as lions and cheetahs competing for gazelles.

Density-Dependent Factor

A factor whose effect on population size depends on density, such as disease, competition, and predation.

Density-Independent Factor

A factor affecting population size regardless of population density, such as pollutants in the environment.

Type I Survivorship Curve

A survivorship curve where most individuals live out their lifespan and die of old age, typical of humans in well-developed countries.

Type II Survivorship Curve

A survivorship curve where individuals die at a constant rate across their lifespan, typical of birds and rodents.

Type III Survivorship Curve

A survivorship curve where most individuals die early in life, typical of fishes, invertebrates, and plants.

Simpson's Diversity Index

A measure of community diversity calculated using $\text{Diversity Index} = 1 - \sum \left(\frac{n}{N}\right)^2$.

Parasitism

A symbiotic relationship where one organism benefits while harming the host organism.

Commensalism

A symbiotic relationship where one organism benefits and the other is neither helped nor harmed.

Mutualism

A symbiotic relationship where both interacting organisms benefit.

Species Richness

The total number of different species living in a habitat or biome.

Relative Species Abundance

The number of individuals in a species relative to the total number of individuals across all species within a habitat.

Competitive Exclusion Principle

The principle stating two species cannot occupy the exact same niche in a habitat if they compete for all the same resources.

Resource Partitioning

The division of environmental resources by coexisting species to minimize competition, such as birds occupying different heights of a tree.

Foundation Species

A species that forms the primary physical structure or base of an ecosystem, such as kelp forming kelp forests.

Keystone Species

A species whose presence is key to maintaining biodiversity and community structure within an ecosystem, such as sea otters.

Invasive Species

Non-native species introduced to a new area that cause damage by taking away habitat and food sources from native species.

Pioneer Species

Hearty plants and lichens with few soil requirements that break down substrate into soil during succession.

Primary Succession

Ecological succession occurring on bare substrate (like rock) that lacks pre-existing soil.

Secondary Succession

Ecological succession occurring after a disturbance that disrupts a community but leaves soil intact.

Eutrophication

A process where nutrient runoff causes excess growth of microorganisms, depleting dissolved oxygen and killing ecosystem fauna.

Biomagnification

The process by which certain toxic substances become more concentrated at each successive level of a food chain.

In terms of homeostatic temperature, what mechanisms do endotherms use to maintain thermoregulation (maintain internal body temperature) in warm climates? Colder climates?

In warm climates, animals can experience panting to cool down, seek out water or shade, etc. In cold climates, endothermic animals have some form of insulation, such as fur, fat, feathers, or some combination thereof. Animals with thick fur or feathers create an insulating layer of air between their skin and internal organs. 

How does cooperative behavior lead to increased evolutionary fitness?

Cooperative behavior allows for survival of many individuals as all individuals are benefitting from the collective goal. This also leads to overall increased survival of individuals within a population. Also, larger groups being better at avoiding predators or competing with other groups.

What happens to the energy that is not passed on to the next trophic level?

It is released as heat, lost in feces (undigested biomass), and organisms that die and are not eaten

Why are food chains limited to a maximum of six levels?

There is too little energy/biomass flow to support a population at higher levels than 6

The hydrologic (water) cycle involves water movement and storage within the ___

hydrosphere

What minerals are cycled from land to water by rain and surface runoff?

Carbon, nitrogen, phosphorous, and sulfur

What are the reservoirs on this planet that water held in? 

Oceans, surface water, the atmosphere, and living organisms

What is the carbon building block that is used by autotrophs to make carbohydrates (i.e. glucose)?

Carbon dioxide

What is the largest reservoir of nitrogen?

The atmosphere

Explain how weathering of rocks is involved in the phosphorus cycle.

The phosphorus cycle involves weathering rocks releasing phosphate (PO₄^3-) into soil and groundwater.

What is the role of producers in the phosphorus cycle?

Producers take in phosphate, which is incorporated into biological molecules.

How does phosphorus return to soil and therefore the environment?

Phosphorus returns to soil via decomposition of biomass, or excretion. 

What conditions must be met in order for exponential population growth to occur?

There are no limiting factors-population has unlimited access to resources and suitable habitat

The population has a high reproductive rate

The population has a low mortality rate

Can exponential growth happen indefinitely in nature? Why or why not?

No, because eventually, the population will reach the carrying capacity of its environment, meaning it will no longer be able to continue growing at the same rate due to limited resources and other factors (limiting factors).  

What influences the carrying capacity of a population?

Limiting factors

Discuss THREE factors that might cause the fluctuations shown in phase B in the graph to the right. (phase B is carrying capacity)

Three biologically sound factors that discuss the rise or fall of population size. Density-dependent factors include limited resources, predation (predator/prey cycles), disease, and reproduction. Density-independent factors must reflect the periodic nature of the curve and cannot include cataclysmic events such as earthquakes, volcanoes, etc.

If your population is limited due to density-dependent and density-independent factors, which model of growth would you see: exponential or logistic?

logistic

Explain why biodiversity is important for the health of ecosystems

Greater biodiversity in ecosystems, species, and individuals leads to greater stability. Each species plays a role in ecosystem function; therefore, species diversity as well as ecosystem diversity are essential to maintaining ecosystem services

What is the relationship between ecosystem biodiversity and stability?

There is a direct relationship between ecosystem biodiversity and stability.

What makes an invasive species invasive?

They are non-native species that were brought to a new location and caused damage to the ecosystem. They can take away habitat and food sources from native species. 

What are the five of the most significant human related effects on ecosystems today?

Habitat Loss, Pollution, Invasive species, Overexploitation of Natural Resources, & climate change