STEM Summative #2: Ecosystems

predator

the organism that does the killing for energy and nutrients

prey

the organism that gets killed

organism

a living thing that lives in different types of surroundings, habitats, or environments; has a variety of adaptations that are suited to its specific living conditions and help it survive

niche

the role of an organism in its habitat; includes what type of food the organism eats, how it obtains this food, what other organisms eat it, when and how the organism reproduces, and the physical conditions it requires to survive

abiotic factor

the parts of a habitat that are non-living or once were living, and which interact with an organism 

biotic factor

the parts of a habitat that are living and which interact with an organism

competition

the struggle between organisms to survive as they attempt to use the same limited resources

predation

an interaction in which one organism kills another for food or nutrients

symbiosis

a type of interaction among organisms; symbiosis is any relationship in which two species live closely together and at least one of the species benefits because of this; means “with life”

mutualism

a relationship in which both species benefit

commensalism

a relationship in which one species benefits and the other species is neither helped nor harmed

parasitism

a relationship that involves one organism living with, on, or inside another organism while harming it; typically does not kill it

producer

an organism that can make its own food; the source of all the food in an ecosystem; obtains energy from different sources such as sunlight and rocks found deep beneath the ground

consumer

an organism that obtains energy by feeding on other organisms; classified by what they eat (herbivore, carnivore, omnivore)

decomposer

breaks down biotic wastes and dead organisms and return the raw materials to the ecosystem; also called “nature’s recyclers”

food chain

a series of events in which one organism eats another and obtains energy; shows only one possible path along which energy can move through an ecosystem

levels of a food chain

(left to right or bottom to top) producer (autotroph), first level consumer, second level consumer, tertiary consumer

food web

consists of many overlapping food chains in an ecosystem; a more realistic way to show the flow of energy through an ecosystem

importance of a food chain/web

They show how each organism depends on another for their food source. If something happens to just one animal on the food chain/web, that can affect the whole thing.

energy pyramid

a diagram that shows the amount of energy that moves from one feeding level to another in a food web

levels of an energy pyramid

In an energy pyramid, the most energy is available at the producer level of the pyramid (the bottom). As energy moves up the pyramid, each level has less energy available than the level below.

How do humans affect the ecosystem?

agriculture and overuse of resources

What factors affect biodiversity?

climate, area, niche diversity, genetic diversity, extinction of species

How do humans positively affect biodiversity?

captive breeding, laws and treaties, habitat preservation

How do humans negatively affect biodiversity?

damaging biodiversity, habitat destruction, poaching, pollution, exotic species

limiting factors

an environmental factor that causes a population to stop growing or decrease in size

examples of limiting factors

climate, space, food and water

carrying capacity

the number that continues to repeat the most even though it may increase or decrease; means that the area might be able to sustain that amount; has enough resources available besides the limiting factors to sustain the amount of organisms every year

How do you calculate energy from an energy pyramid?

to calculate energy from an energy pyramid, remove a 0 (or divide by 10) each time moving up

agriculture

Technologies negatively affect the environment. With fewer trees to take in carbon dioxide, more of it remains in our atmosphere. Fertilizers may increase plant/algae growth, killing animals living in the water

overuse of resources

Humans overusing the resources in an ecosystem affects plants and animals living there; can lower or kill population of sea-life/grassland animals 

climate

The continuous growing season is tropical rainforests means that food is always available for other organisms

area

A large area would usually contain more species than a small area

niche diversity

A coral reef supports many different niches, enabling a greater number of species to live in it than more of a uniform habitat does

genetic diversity

The greatest genetic diversity exists among species of unicellular organisms; organisms inherit genes from their parents; both the shared genes and the genes that differ among individuals make up the total gene pool of that species; species that lack a diverse gene pool are less able to adapt to and survive changes in the environment

extinction of species

Once a population drops below a certain level, the species may not recover; human habitat destruction, hunting, or other activities affect the survival of populations (can lead to extinction).

captive breeding

the mating of animals in zoos or on wildlife preserves; scientists care for the young and then release them into the wild; the young are raised and trained by volunteers to learn the correct behaviors (such as knowing how and where to migrate)

laws and treaties

the Endangered Species Act prohibits trade of products made from threatened or endangered species; requires the development of plans to save endangered species; lists over 800 threatened/endangered species that cannot be traded for profit

habitat preservation

protecting whole ecosystems saves endangered species, the species the depend upon, and the species that depend upon them; ecosystems with high biodiversity are considered healthier than ecosystems with low biodiversity; the completeness of an ecosystem’s biodiversity is one measure of its health

damaging biodiversity

Natural events and human activities can threaten biodiversity and cause extinction.

habitat destruction

the loss of a habitat; the major cause of extinction; habitat fragmentation is breaking larger habitats into smaller, isolated pieces, or fragments

poaching

the illegal killing or removal of wildlife from their habitats; some endangered species are valuable to poachers

pollution

can cause some species to become endangered; may reach animals through their water, air, or food; may kill or weaken organisms or cause birth defects

exotic species

Introducing exotic species into an ecosystem can threaten biodiversity; can outcompete and damage native species

autotroph

an organism that makes its own food

heterotroph

an organism that gets its food from another organism