Organism that relies on other organisms for its energy and food supply; also called heterotroph.
Consumer
each step in a food chain or food web.
trophic level
total amount of living tissue/mass within a given trophic.
biomass
The nitrogen cycle is an example of which cycle:
biogeochemical, decomposer, energy, or water
biogeochemical
On average about 10% of energy available within the trophic level is transferred to the next.
True
single essential nutrient that limits productivity in an ecosystem.
limiting nutrient
chemical substance that an organism needs in order to sustain life.
nutrient
First producer of energy rich compounds that are later used by other organisms.
Primary producer
In a process known as ___, some types of soil bacteria obtain energy by converting nitrates into nitrogen gas.
Denitrification
True or False
Nitrogen when in the form of ammonia, nitrate, and nitrite is found in soil.
True
An organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds.
Autotroph
Organism that obtains food by consuming other living things; also called consumers.
Heterotroph
process by which bacteria convert nitrates into nitrogen gas.
denitrification
Ecologists measure ___ in grams or organic matter per unit area.
biomass
True or False
Organic phosphate is taken up by producers during photosynthesis and released by cellular respiration.
False
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem.
food web
model of the relative amounts of energy matter contained within each trophic level in a given food chain or food web.
ecological pyramid
process of converting nitrogen gas into nitrogen compounds that plants can absorb and use.
nitrogen fixation
True or False
Plants absorb phosphorus from the atmosphere or water.
False
They absorb it from soil minerals.
Process used by plants and other autotrophs to capture light energy and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy rich carbohydrates such as sugars.
Photosythesis
Series of steps in an ecosystem in which organisms transfer energy by eating and being eaten.
Food chain
process in which elements, chemical compounds, and other forms of matter are passed from one part of the biosphere to another.
biogeochemical cycle
True or False
The more levels that exist between a producer and consumer, the larger % of the original energy from producers is available to that consumer.
False.
Less energy is available the more it goes up the trophic levels.