Ch. 3-1, 3-2, 3-3, and 4-2 Bio Ecology
community
a collection of different populations that live together with their physical environment at the same time
ecosystem
a community of living organisms in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system
ecological pyramid
a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web
biome
a group of ecosystems that have the same climate and similar dominant communities
population
a group of individuals that belong to the same species and live in the same area at the same time
species
a group of organisms so similar to one another that they can breed together and produce fertile offspring in nature
food chain
a series of steps in which organisms transfer energy by eating and being eaten
biotic factors
all the living things with which organisms interact
symbiosis
any relationship in which two species live closely together
where is the most nitrogen found on earth
atmosphere
why can each trophic level support only about one tenth the amount of living tissue of the level below it?
because each tropic level harvests only 1/10 of the energy from the level below it. 90% is used for life processes or lost as heat.
why cant most organisms use nitrogen in atmosphere
because it hasnt been fixed yet, changed from N2 to nH3, nO2, nO3
why is only part of the energy stored in one trophic level is passed on to the next level
because organisms use a lot of the energy on the respiration movement and reproduction and some remaining energy is released into the environment
what are organisms in ecosystems influenced by
biological, biotic and physical or abiotic
mutualism
both species benefit from the relationship +/+
decomposers
break down organic matter (fungi, bacteria)
niche
consists of all the physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
trophic level
each step in a food chain or food web 1st trophic level- producers higher trophic levels- consumers
omnivores
eat both plants and animals (humans, bears, crows)
detritivores
eat plant and animal remains and other dead matter (earthworms, crabs, vultures)
how do organisms get nitrogen they need
eat plants or eat something that eats plants
types of ecological pyramids:
energy, biomass, and pyramids of numbers
how does energy flow through an ecosystem
it flows in one direction only; from the sun or chemicals to autotrophs to heterotrophs
what is at the core of every organsims interaction with the environment?
its need for energy to power lifes processes
food web
links together all the food chains in an ecosystem
biogeochemical cycles
matter moves through an ecosystem
nitrogen cycle
needed by all organisms to build protiens
nitrates
nitrogen compounds
predation
one organism captures and eats another
commensalism
one species benefits and the other is neither helped nor harmed +/0
parastism
one species benefits by living in or on the other and the other is harmed +/-
carnivores
only eat animals (cheetahs, snakes, lions)
herbivores
only eat plants (cows, rabbits)
autotrophs (producers)
organisms that can capture energy from sunlight or chemicals and use that energy to produce food
heterotrophs (consumers)
organisms that rely on other organisms for their energy and food
competition occurs when
organisms try to use the same resources or necessities of life
4 elements that make up over 95% of the body in most organisms
oxygen, carbon, hydrogen, nitrogen
how is carbon brought from atmosphere into living organisms
photosynthesis
matter is
recycled within and between ecosystems and the biological systems do not use up the matter they only change it
pyramid of numbers
shows the relative number of individual organisms at each trophic level
habitat
the area where an organism lives
nutrients
the chemical substances that an organism needs to survive
host
the organism from which a parasite obtains nutritional needs
biosphere
the parts if the planet in which life exists; includes land, water, and air, or atmosphere - all living things and their non-living environment - the highest level of organization ecologists study
chemosynthesis
the process in which autotrophs use chemical energy to produce chemical energy (preformed only by certain types of bacteria)
photosynthesis
the process in which autotrophs use light energy to make food (carbon dioxide and water into oxygen and carbohydrates)
evaporation
the process in which water changes from a liquid into a gas
transpiration
the process in which water evaporates from the leaves of plants
what do biotic and abiotic factors together determine
the productivity of the ecosystem - how productive it is
primary productivity of an ecosystem
the rate at which organic matter is created by producers
ecology
the scientific study of interactions among organisms and their environment; study of all the different levels of life, ranging from the individual organism to the biosphere
who do consumers depend on for their energy
the trophic level below it
other source of energy is it isnt the suns
they use the energy stored in inorganic chemical compounds
limiting nutrient
when an ecosystem is limited by a single nutrient that is scarce or cycles very slowly
biochemical cycles
when matter is passed from one organism to another and from one part of the biosphere to another
carbon cycle
- a key ingredient of living tissue - processes involved; photosynthesis and human activities such as burning