Biology - Ecosystems test

Biodiversity

variety of species of organisms in their natural habitats

genetic diversity

variety of genes in species

species diversity

variety of species within a community

ecosystem diversity

number and variety of ecosystems in an area

species

a group of organisms where individuals produce fertile offspring

population

group of organisms of some species in the same area at the same time

community

a group of populations living together in given area

ecosystem

a community of ecosystems and their physical environment interacting as a system. Relationship between biotic and abiotic factors in a shared environment.

ecological succession

undirected changes that take place over extended periods of time.

symbiotic relationships

interactions between different species in an ecosystem that benefit one or both organisms.

mutualism

a type of symbiotic relationship where both species benefit from the interaction.

commensalism

a type of symbiotic relationship where one species benefits while the other is neither helped nor harmed.

parasitism

a type of symbiotic relationship where one species benefits at the expense of the other.

competition

the relationship between two or more species competing for the same resources in an ecosystem.

predation

a type of symbiotic relationship where one species hunts and feeds on another.

autotrophs

organisms that convert inorganic material into organic molecules required for life, through photosynthesis or chemosynthesis.

heterotrophs

organisms that obtain organic molecules by consuming other organisms, as they cannot produce their own food.

producers

organisms that produce organic compounds from carbon dioxide and sunlight, serving as a food source for heterotrophs in an ecosystem.

consumers

organisms that consume organic material for energy, including herbivores, carnivores, and omnivores.

energy pyramids

show loss of energy at each feeding level in a food chain, only 10% of energy is passed down to other levels. other 90% is lost in form of hear and animal metabolism.

trophic levels

organisms that obtain energy in a community from a common source, grouped according to how they can obtain energy for requirements.

primary producers

energy gained through the sun (photoautotroph) or inorganic materials (chemoautotrophs)

primary consumer

energy obtained through consuming primary producers

secondary consumer

energy obtained through consuming primary consumer

tertiary consumer

energy obtained through consuming secondary consumers

food chains

shows how each living thing gets its food.

food webs

show feeding relationships, complex network of intertwined food chains.

decomposer

gain their nutrients from dead material produced through other trophic levels. recycle by breaking down dead organic material and returning nutrients back into the environment.

saprotrophs

secrete digestive enzymes into dead organic material and digest externally

detritivores

ingest dead organic matter and digest internally and absorb.

primary succession steps

process of a lifeless ecosystem being colonised by progressively more stable ecosystems. FIRST is a pioneer species, colonises a new site, typically lichens or moss with no soil present. SECOND pioneer species die resulting in and creates first organic soil. THIRD grasses grow and displace pioneer species. FOURTH more nutrients in soil allows shrub growth. FIFTH increased soil depth allows tree growth.

biomass

the amount of organic matter comprising a group of organism in a habitat.

secondary succession

Occurs after an ecological disturbance such as fire, the reestablishment of an ecosystem following disturbance.

adaptations

a feature of an organism that allows them to live successfully, favoured by natural selection.

structural adaptations

body structures that allow an animal to find and consume food, defend itself and to reproduce its species. e.g, camouflage, mimicry, chemical defences, body parts.

physiological adaptations

features that are not visible normally associated with the internal metabolic processes.

behavioural adaptations

features that are associated with the patterns of activity of behaviour, e.g, migration, nocturnal, hibernation.

carbon cycle definition

The circulation of carbon on earth in which atmospheric carbon dioxide is converted to organic nutrients through photosynthesis and is again converted back to the inorganic state by respiration, decay, or combustion.

carbon cycle starts..

when the plants take in CO2 during the process of photosynthesis. During photosynthesis, Plants convert CO₂ into glucose.

carbon cycle during

During the process or respiration (breathing),Organisms (plants and animals) release CO₂ back into the atmosphere.

carbon cycle decomposers

will decompose and break down dead matter, returning carbon to the soil. Another factor working in the carbon cycle is the burning fossil fuels releases stored carbon into the atmosphere.

nitrogen cycle definition

Nitrogen is an important component of proteins and other molecules that are required by living things. The earth’s atmosphere has about %78of nitrogen gas Plants and other living things cannot take atmospheric nitrogen unless fixed with other elements.

nitrogen fixation

Bacteria convert atmospheric N₂ into usable forms for plants. During this process the nitrogen gas is fixed into the soil by the bacteria The nitrogen-fixing bacteria in the soil and within the root nodules of some plants convert nitrogen gas in the atmosphere to ammonia.

habitat fragmentation

occurs when natural forests are broken up into smaller, isolated patches of natural ecosystems – do not adequately sustain communities of organisms and therefore biodiversity. native vegetation is cleared, habitats for native species destroyed, the diversity of habitats is reduced, major disruptions to ecological processes.

climate change

With higher carbon dioxide concentrations, increasing temperatures, altered rainfall patterns, rising sea levels and acidification of the oceans impact on habitats, ecosystems and species will be widespread.

introduced species

Human activity results in an organism being introduced to an area, where it did not previously occur. Impacts of an alien species are usually only significant if it increases in number and spreads rapidly (invasive) because the normal limiting factors in the habitat is missing (like a predator, diseases and competition, which in the natural habitat will control the population size)

agriculture

the main polluter of waterways, The use of fertilizers to increase nutrients and increase crop productivity is common in agriculture. Excess nitrogen and phosphorus in fertilisers will enter waterways causing pollution of streams, rivers, lakes and other waterbodies.