UConn Bio Exam 8

Extinction

Extinction occurs when every single member of an endangered species has been wiped clean off the face of the earth; they no longer exist.

Genetic Diversity

The variation within species in their DNA, behaviors, appearance, and other inherited traits, shaped by evolution.

Species Diversity

The variety of different species within a community, including prey, predators, and specialists.

Ecosystem Diversity

The differences between ecosystems in terms of structure, function, and species composition.

Endangered Species

A species that is very close to extinction and at risk of being wiped off the earth.

Threatened Species

A species that is at risk of becoming endangered but not yet at immediate risk of extinction.

Problems with Introduced Species

Introduced species often lack natural predators, diseases, or parasites in their new environment, disrupting ecosystem balance.

Extinction Vortex

A process where small population sizes lead to decreased reproduction and survival, accelerating extinction risk.

Minimum Viable Population

The smallest population size needed for a species to survive and sustain itself.

Movement Corridors

Narrow strips of habitat connecting isolated patches of land to allow animal movement and gene flow.

Nature Reserves

Protected areas that serve as biodiversity islands amid habitats degraded by human activity.

Bioremediation

The use of living organisms (fungi, bacteria, plants) to detoxify and restore damaged environments.

Biological Augmentation

The addition of essential nutrients to an environment using organisms, such as nitrogen-fixing bacteria enriching soil.

Biophilia

The innate human sense of connection to nature and caring for the environment.

Energy flow and matter cycling in ecosystems

Energy flows through the ecosystems through food and waste, and then matter cycles through the ecosystem with all the cycles through the ecosystem. Energy flows from the primary producers to the tertiary consumers.

Producers

Organisms that make their own food using sunlight through photosynthesis; autotrophs that form the base of the food chain.

Primary Consumers

Herbivores that eat plants or producers.

Secondary Consumers

Carnivores that eat primary consumers (herbivores).

Tertiary Consumers

Carnivores that eat secondary consumers (other carnivores).

Decomposers

Organisms (detritivores) that consume dead, nonliving organic matter, recycling nutrients back into the ecosystem.

Producers (general)

Organisms that make their own food and produce nutrients for consumers.

Consumers

Organisms that eat food produced by producers or other consumers.

Autotrophs

Producers that make nutrients using sunlight and photosynthesis.

Heterotrophs

Organisms that create nutrients by consuming organic material (consumers).

Primary Productivity

The amount of solar energy converted to chemical energy by autotrophs in a given time.

Gross Primary Production

Total amount of primary production in an ecosystem.

Net Primary Productivity

Total primary production minus energy used for respiration.

Secondary Productivity

Amount of chemical energy in food converted to new biomass during a given period.

Energy Transfer (Efficiency)

About 10% of energy transfers from one trophic level to the next, creating a pyramid with decreasing energy at higher levels.

Energy Pyramid

Visual representation of energy flow; typically starts with 1,000,000 joules at producers and ends with about 10 joules at tertiary consumers.

Biomass

The total mass of living organisms or energy contained in a given area or volume.

Biomagnification (toxins)

Increase in concentration of toxins as they move up trophic levels in a food chain.

Water Cycle

Water moves through evaporation, transpiration, condensation, precipitation, and surface/groundwater flow.

Nitrogen Cycle

Nitrogen from the atmosphere (N2) is fixed into forms usable by plants (NH4+, NO3–), cycled through ammonification, nitrification, and denitrification.

Phosphorus Cycle

Phosphorus cycles mainly through sedimentary rocks, oceans, and organisms without atmospheric involvement, moving via runoff, consumption, and sedimentation.

Carbon Cycle

CO2 is cycled between atmosphere and organisms through photosynthesis, respiration, and burning of fossil fuels.

Global Warming

Increase of atmospheric greenhouse gases (like CO2) from human activities causes climate change.

Ozone Depletion

Chlorine-containing pollutants released by humans degrade the ozone layer in the atmosphere.

Competitive Exclusion

When two species compete so intensely for the same resources that one species completely eliminates the other from the area

Niche (realized vs ideal)

The role and conditions a species occupies in an environment

Competition (-/-)

An interaction where both species are harmed by competing for the same limited resources, sometimes leading to death or exclusion

Predation & Herbivory (+/-)

A relationship where one species benefits by eating another, either animals hunting prey (predation) or animals eating plants (herbivory)

Symbiosis (mutualism +/+, parasitism +/-, commensalism +/o)

Close interactions between species where both benefit (mutualism), one benefits and the other is harmed (parasitism), or one benefits without affecting the other (commensalism)

Batesian vs Mullerian mimicry

Batesian mimicry is harmless species mimicking harmful ones, Mullerian mimicry is two harmful species resembling each other

Cryptic Coloration

Camouflage used by prey to avoid detection by predators

Character Displacement, Resource Partitioning

Changes in species behavior or resource use to reduce competition and avoid conflict or death

Species Richness

The number of different species present in a community, contributing to biodiversity

Trophic Levels

The hierarchical levels in an ecosystem including producers, consumers, and decomposers

Dominant Species, Keystone Species

Dominant species have highest abundance and biomass, controlling community structure

Relative Abundance

The proportion each species represents of the total individuals in an ecosystem

Invasive Species

Non-native species introduced artificially that disrupt ecosystems by outcompeting native species and spreading diseases

Non-Equilibrium Model

A theory that ecosystems are constantly changing due to disturbances and never reach a stable balance

Intermediate Disturbance Hypothesis

The idea that moderate levels of disturbance maintain species diversity, while too little or too much disturbance reduces diversity

Population Density

The number of individuals per unit area or volume, showing how crowded or spread out a population is within a region

Dispersion

The pattern of spacing among individuals within a population’s boundaries, showing how organisms are arranged in their habitat

Clumped Dispersion

A distribution pattern where individuals are grouped in patches, often due to resource availability or social behavior

Uniform Dispersion

A distribution pattern where individuals are evenly spaced, often due to territorial behavior or competition

Random Dispersion

A distribution pattern with no predictable spacing, usually due to the absence of strong attractions or repulsions

Carrying Capacity

The maximum number of individuals an environment can support sustainably

Demography

The study of population statistics and how they change over time, focusing on birth and death rates

Birth Rate

The rate at which offspring are produced in a population over time

Death Rate

The rate at which individuals die in a population over time

Life Table

A graphic showing the survival pattern of a population at different ages, often based on a cohort

Exponential Growth

A growth pattern with no environmental limits, resulting in a J-shaped curve representing rapid increase

Logistic Growth

A growth pattern that levels off as it approaches the environment’s carrying capacity, forming an S-shaped curve

Survivorship Curve

A graphical representation of life table data showing survival rates at different life stages

Type I Survivorship

A pattern with low early-life death and high late-life death, common in humans and large mammals

Type II Survivorship

A pattern where death rate remains constant across the lifespan, often seen in rodents or birds

Type III Survivorship

A pattern with high early-life death but lower death in adulthood, often seen in fish or insects

J-Curve

A curve representing exponential growth, with rapid increase forming a J-shape

S-Curve

A curve representing logistic growth, leveling off at the carrying capacity, forming an S-shape

N

Represents the population size within an environment in population growth models

K

Represents the carrying capacity or the maximum sustainable population size in an environment

Allee Effect

A situation where individuals struggle to survive or reproduce due to having too small a population size

Density Dependent Factors

Factors that change with population density and can limit growth, like disease, competition, and waste buildup

Density Independent Factors

Factors that affect population growth regardless of size, like natural disasters or weather

Density Dependent Selection

Natural selection that favors traits helping survival and reproduction in crowded environments (K-selection)

Density Independent Selection

Natural selection that favors traits for rapid reproduction in uncrowded environments (r-selection)

Ecological Footprint

The effect a species has on its surrounding ecosystem, including resource use and environmental impact