abiotic
One of the components that make up the biosphere and its ecosystem; consists of nonliving components such as water, air, nutrients, rocks, heat, and solar energy.
aerobic respiration
uses oxygen to convert glucose (or other organic nutrient molecules) back into carbon dioxide and water.
anaerobic respiration/fermentation
A form of cellular respiration; Some decomposers get the energy they need by breaking down glucose (or other organic compounds) in the absence of oxygen.
aquatic life zones
Numerous divisions of the watery parts of the biosphere
atmosphere
a thin spherical envelope of gases surrounding the earth's surface.
biogeochemical cycle
(literally, life-earth-chemical cycles) or nutrient cycles�prime examples of one of the four scientific principles of sustainability
biomass
the dry weight of all organic matter contained in its organisms.
biomes
large regions such as forests, deserts, and grasslands, with distinct climates and certain species (especially vegetation) adapted to them.
biosphere
consists of the parts of the earth's air, water, and soil where life is found.
biotic
consists of living and once living biological components�plants, animals, and microbes.
carbon cycle
the basic building block of the carbohydrates, fats, proteins, DNA, and other organic compounds necessary for life. It circulates through the biosphere, the atmosphere, and parts of the hydrosphere, in the __________
cell theory
The idea that all living things are composed of cells is called the cell theory and it is the most widely accepted scientific theory in biology.
cells
the smallest and most fundamental structural and functional units of life.
chemosynthesis
A few producers, mostly specialized bacteria, can convert simple inorganic compounds from their environment into more complex nutrient compounds without using sunlight,
community, or biological community
consists of all the populations of different species that live in a particular place
consumers
cannot produce the nutrients they need through photosynthesis or other processes and must obtain their nutrients by feeding on other organisms (producers or other consumers) or their remains.
decomposers
primarily certain types of bacteria and fungi, are consumers that release nutrients from the dead bodies of plants and animals and return them to the soil, water, and air for reuse by producers.
detritus
dead bodies of organisms
detritus feeders, or detritivores
feed on the wastes or dead bodies of other organisms
ecological efficiency
The percentage of usable chemical energy transferred as biomass from one trophic level to the next
Ecology
the study of how organisms interact with their living (biotic) environment of other organisms and with their nonliving (abiotic) environment of soil, water, other forms of matter, and energy mostly from the sun.
ecosystem
a community of different species interacting with one another and with their nonliving environment of soil, water, other forms of matter, and energy, mostly from the sun.
eukaryotic cell
surrounded by a membrane and has a distinct nucleus and several other internal parts called organelles, which are also surrounded by membranes.
food chain
sequence of organisms, each of which serves as a source of food or energy for the next
food web
a complex network of interconnected food chains
genetic diversity
variation in a population
geosphere
consists of the earth's intensely hot core, a thick mantle composed mostly of rock, and a thin outer crust.
greenhouse gases
trap heat and thus warm the lower atmosphere. Almost all of the earth's weather occurs in this layer.
gross primary productivity (GPP)
the rate at which an ecosystem's producers (usually plants) convert solar energy into chemical energy as biomass found in their tissues.
habitat
place where a population or an individual organism normally lives
hydrologic cycle, or water cycle
collects, purifies, and distributes the earth's fixed supply of water.
hydrosphere
consists of all of the water on or near the earth's surface.
limiting factor principle
Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance
limiting factors
Sometimes one or more factors, known as __________, are more important in regulating population growth than other factors are.
natural greenhouse effect
Without this the earth would be too cold to support the forms of life we find here today.
net primary productivity (NPP)
the rate at which producers use photosynthesis to produce and store chemical energy minus the rate at which they use some of this stored chemical energy through aerobic respiration.
nitrogen cycle
two natural processes convert or fix N2 into compounds useful as nutrients for plants and animals
omnivores
feed on both plants and animals.
phosphorus cycle
Phosphorus circulates through water, the earth's crust, and living organisms
photosynthesis
producers capture sunlight to produce energy-rich carbohydrates which is the way energy enters most ecosystems
population
a group of individuals of the same species that live in the same place at the same time.
primary consumers, or herbivores
(plant eaters), are animals such as rabbits, grasshoppers, deer, and zooplankton that eat producers, mostly by feeding on green plants.
producers
make the nutrients they need from compounds and energy obtained from their environment.
prokaryotic cell
surrounded by a membrane, but it has no distinct nucleus and no other internal parts surrounded by membranes.
pyramid of energy flow
illustrates the energy loss for a simple food chain, assuming a 90% energy loss with each transfer
range of tolerance
An organisms ability to adapt to variations in its physical and chemical environment.
secondary consumers, or carnivores
(meat eaters), are animals such as spiders, hyenas, birds, frogs, and some zooplankton eating fish, all of which feed on the flesh of herbivores.
species
a set of individuals that can mate and produce fertile offspring.
stratosphere
stretching 17-50 kilometers (11-31 miles) above the earth's surface lower portion contains enough ozone (O3) gas to filter out most of the sun's harmful ultraviolet radiation.
sulfur cycle
Sulfur circulates through the biosphere in this cycle
third- and higher-level consumers
carnivores such as tigers, wolves, mice-eating snakes, hawks, and killer whales (orcas) that feed on the flesh of other carnivores.
transpiration
Over land, about 90% of the water that reaches the atmosphere evaporates from the surfaces of plants through a process called transpiration.
trophic level
Ecologists assign every organism in an ecosystem to a ___________ depending on its source of food or nutrients.
troposphere
a thin spherical envelope of gases surrounding the earth's surface. Its inner layer, the troposphere, extends only about 17 tropics and about 7 kilometers (4 miles) above the earth's north and south poles.