Environmental Science 13 Midterm 2

Symbiosis

A process where two or more species live intimately together

Keystone species

Critical role in a biological community

Effect of species on communities ripples across multiple levels

Mutualism

Both species clearly benefit

EX: Butterfly and flower

Commensalism

One member benefits and the other neither benefited nor harmed

EX: Bromeliad grows on the trunk of a tropical tree

Parasitism

One partner benefits while the other is harmed (formed of predation)

EX: Mosquito on human

Carrying capacity

The maximum population size that a particular environment can sustain over time. Resources become limited, and the death rate rises

Survivorship curve

Uses the life history data to show the number of individuals surviving at each age interval, over time

Exponential (R) growth

Population growth has no limits and has a distinctive shaped “J” growth curve when graphed over time

Simple description of the real world

Populations of a species lose individuals and experience reduced biotic potential

Demography

Vital statistics about people

EX: Births/Deaths, Where they live? and total population size

Mass extinctions

An event of synchronous extinction of many species, occurring over a relatively short period of time. May be caused by natural or anthropogenic forces.

Wildlife corridors

Strips of land that connect disjunct paracels of habitat allow for the movement and dispersal of individuals, and promote the genetic integrity of the population

Domain bacteria

Microscopic, unicellular prokaryotes (no nucleus)

Species are autotrophs (self-feeding) white others are heterotrophs (eat some-one/thing else)

Domain Archaea

Microscopic, unicellular prokaryotes

Superficially similar to bacteria, significant genetic differences

Domain Eukarya

Unicellular/multicellular organism

Have eukaryotic cells

Includes plant, animal, and fungus kindom

Endangered species Act

U.S legislation protects species

Directs government agencies to help species recover

Habitat restoration

Process of bringing a habitat back to its natural state

Before it was impacted thought destuctive human activties

Invasive species

Accidentally or deliberately introduced species

Thrive in new terrioty where they are free of predators, diseases or resource limitations

Carcinogen

Substanes that cause cancer

Mutagen

Chemicals and radiations, that damage or alter genetic material (DNA) in cells

Teratogen

Chemicals or other factos that specically cause abnormalities during embrotic growth and development

Environmental toxicology

The scientific study of the health effects associated with exposure to toxic chemicals occurring in the natural, work and living environments

Biogeography

Study of where organims live and why they live there

Evolution

The change in a population over multiple generations

Natural selection

Leads to adaptation

Survival of the fittest

K-Selected Species

Adapted to stable, predictable environments

Tend to have larger (but fewer) offspring and contribute large amounts of resources to each offspring

EX: Elephants, humans

R-selected Species

Adapted to unstable and unpredictable environments

Large numbers of small offspring

Do not provide resources or parental care to offspring

EX: Jellyfish, Dandelion

Distribution Patterns

The distribution of individuals within a habitat at a particular point in time

Distribution: Randomly

Individuals live wherever resources are available and chance events allow them to settle

EX: Dandelions

Uniform

Patterns arise from competition and territoriality

EX: Penguins

Distribution: Clumped

Patterns result when species clump together for protection, mutual assistance or reproduction

EX: Elephant or school of fish

Community

Multiple species co-ocuring in a place at a time, and possibly interacting with each other

Ecological niche

Full range of conditions or resources used in which a species could maintain a stable population in the absence of other species

Domain

Refers to a specific area of knowledge or a distinct category of living organisms

Mimicry

Variation in the wild

Mimics variation in domesticated plants and animals

Speciation

New species can form rapidly once divergence begins

Biodiversity

The richness of biological variation, including genetic variability as well as species and community richness.

Anthropogenic

Occurring as a result of human influence

Autotrophs

An organism that synthesizes its biochemical constituents using simple inorganic compounds and an external source of energy to drive the process.

EX: Primary producer

Endangered

Refers to indigenous species threatened with imminent extinction or extirpation over all or a significant portion

Endemic species

An ecological term used to describe species with a local geographic distribution.

Habitat

The place or “home” where a plant or animal lives, including the specific environmental factors required for its survival.

Heterotroph

An organism that utilizes living or dead biomass as food

Species

An aggregation of individuals and populations that can potentially interbreed and produce fertile offspring, and is reproductively isolated from other such groups.

Kingdom

The system of biological kingdoms is the way in which science classifies living things according to their ancestry over the course of evolution.

Kingdom Plantae

Made up of trees, plants and other species of vegetation

Autotrophic things, whose cells contain cellulose and chlorophyll, are essential for life on Earth since they release oxygen through photosynthesis.

Kingdom Fungi

Includes yeasts, molds, and all species of mushrooms and toadstools

Multicellular aerobic heterotrophic eukaryotes have chitin in their cell walls, feed off other living things, and reproduce through spores.

Kingdom Animalia

Vertebrates and invertebrates

Multi-celled, heterotrophic eukaryotes with aerobic respiration, sexual reproduction, and the ability to move.

Convention on International Trade in Endangered Species Of Wild Fauna and Flors (CITES)

Treated formed to control the international trade of threatened plants and animals

Biodiversity

Diversity of life forms in an environment

Age structure pyramid

Description of how many individuals fit into a particular age categies in a population

Logistic growth model

Growth model that describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment

Predation

An interaction in which one animal typically kills and consumes another animal

Background extinction rate

The natural rate at which species go extinct over long periods of time without human influence.
Scientists compare current extinction rates to this baseline to see how much humans are accelerating extinctions.

Biodiversity hotspot

A region with extremely high biodiversity that is also highly threatened by human activities such as deforestation or development.
These areas are priorities for conservation.

Example: Madagascar, Tropical Andes.

Biodiversity loss

The reduction in the variety of life in an area or on Earth.
It can occur through:

• species extinction

• habitat destruction

• pollution

• climate change

• invasive species

Preserve

A protected natural area where human activities are very limited or prohibited to protect ecosystems and wildlife.

Example: national parks and wildlife reserves.

Taxonomy

The science of naming, classifying, and organizing organisms based on shared characteristics.

The main hierarchy:

• Domain

• Kingdom

• Phylum

• Class

• Order

• Family

• Genus

• Species

Cyanobacteria

Photosynthetic bacteria (often called blue-green algae) that were among the first organisms to produce oxygen through photosynthesis.
They played a major role in creating Earth's oxygen atmosphere.

Extremophiles

Organisms that live in extreme environments such as:

• very high temperatures

• extreme acidity

• high salt levels

• deep ocean pressure

Examples exist in hot springs and deep-sea vents.

Protists

A diverse group of mostly single-celled eukaryotic organisms that are not plants, animals, or fungi.

Examples include:

• algae

• amoebas

• paramecium

Unicellular

An organism made of only one cell.

Examples:

• bacteria

• many protists

Multicellular

An organism composed of many specialized cells that work together.

Examples:

• plants

• animals

• fungi

Kyoto Protocol

An international climate agreement (1997) where many countries agreed to reduce greenhouse gas emissions to slow global warming.

Industrialized nations had specific emission reduction targets.

Acute effect

A health effect that occurs immediately or shortly after exposure to a harmful substance.

Examples:

• chemical burns

• poisoning

• dizziness

Chronic effect

A long-term health effect that develops after repeated or prolonged exposure to a toxin.

Examples:

• cancer

• organ damage

• respiratory diseases

Lethal dose-50% (LD-50)

The amount of a substance required to kill 50% of test organisms (usually laboratory animals).

It is used to measure toxicity:

• Lower LD-50 = more toxic

Neurotoxicant

A chemical that damages the nervous system, including the brain, spinal cord, or nerves.

Examples:

• mercury

• lead

• certain pesticides

Endocrine disruptor

Chemicals that interfere with the hormone system of humans or animals.

Effects may include:

• reproductive problems

• developmental abnormalities

• cancer

Examples: BPA, some pesticides.

Traditional hazards

Environmental hazards that mainly affect developing countries, often related to poverty.

Examples:

• unsafe drinking water

• indoor smoke from cooking fires

• poor sanitation

Modern hazards

Hazards produced by industrialization and modern technology.

Examples:

• chemical pollution

• radiation

• industrial waste

• air pollution from factories

“Double burden”

A situation where developing countries face both traditional and modern hazards at the same time.

Example:

• contaminated water and

• industrial chemical pollution

Emerging diseases

Diseases that are new or rapidly increasing in a population.

Example: COVID-19 when it first appeared.

Re-emerging diseases

Diseases that previously declined but are now returning.

Example:

• tuberculosis

• malaria in some regions

Antibiotic resistance

When bacteria evolve so antibiotics no longer kill them effectively.

Caused by:

• overuse of antibiotics

• improper medical use

• agricultural use

Biological agents

Living organisms or biological substances that can cause disease or environmental harm.

Examples:

• bacteria

• viruses

• fungi

• parasites

Chemical agents

Toxic chemical substances that can harm living organisms or ecosystems.

Examples:

• pesticides

• heavy metals

• industrial chemicals

Bioremediation

A process that uses living organisms (usually microbes or plants) to clean up pollution.

Examples:

• bacteria breaking down oil spills

• plants absorbing heavy metals from soil