61 terms

Biology chapter 3

biology chapter 3
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Terms in this set (...)

Ecology
the scientific study of interactions between organisms and their environments, or surroundings
Biosphere
Contains the combined portions of the planet in whcih all of life exists, including land, water, and air, or atmosphere. the highest level of organization
Species
a group of organisms so similar to one another that they can breed and produce fertile offspring.
Population
Groups of individuals that belong to the same species and live in the same area.
Community
Assemblages of different populations that live together in a defined area.
Ecosystem
a biological community of interacting organisms and their physical environment.
Biome
A group of ecosystems that have the same climate and similar dominant communities
Sunlight
the main energy source for life on Earth
Autotroph
Plants, some algae, and certain bacteria that capture energy from sunlight or chemicals and use that energy to produce food
Producers
make their own food, also called autotrophs
Photosynthesis
When autotrophs use light energy to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches
Chemosynthesis
When organisms use chemical energy to produce carbohydrates; this process is performed by several types of bacteria.
Heterotroph
Organisms that rely on other organisms for their engery and food supply
Consumers
also known as heterotrophs, organisms that eat other organisms for their energy.
Herbivore
A heterotroph that obtains energy by eating only plants.
Carnivore
A heterotroph that obtains energy by eating other animals.
Omnivore
A heterotroph that obtains energy by eating both plants and animals.
Detritivore
A heterotroph that feeds on plant and animal remains and other dead matter.
Examples of Detritivores:
Snails
Crabs
Earthworms
Decomposers
A heterotroph that breaks down inorganic matter.
Energy
flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs and then to various heterotrophs.
Food Chain
A series of steps in which organisms transfer energy by eating and being eaten.
Food Web
Links all the food chains in an ecosystem together.
Trophic Level
Each step in a food chain or food web
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.
Energy Pyramid
Shows the relative amount of energy available at each trophic level. Organisms use about 10% of this energy for life processes, the rest is lost as heat
Biomass Pyramid
Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid; shows the mass of each level
Pyramid of Numbers
Shows the relative number of individual organisms at each trophic level Does not necessarily have the shape of a pyramid
Biomass
The total amounth of living tissue within a given trophic level
Matter
Recycled within and between ecosystems
Biogeochemical Cycle
Elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another.
Evaporation
The process by which water changes from liquid form to an atmospheric gas
Transpiration
When water enters the atmosphere by evaporating from the leaves of plants
Nutrient
All the chemical substances that organisms need to stay alive. passed between organisms and the environment through biogeochemical cycles Chemicals that organisms need to build tissues and carry out life functions
Nitrogen Fixation
When bacteria, which live in the soil and on the roots of plants called legumes, convert nitrogen gas into ammonia.
Denitrification
When soil bacteria convert nitrates into nitrogen gas; this process releases nitrogen into the atmosphere.
Primary Productivity
The rate at which organic matter is created by producers. one factor that controls this is the amount of available nutrients.
Limiting Nutrient
When an ecosystem is limited byt a single nutrient that is scarce or cycles very slowly.
Algal Bloom
When an aquatic ecosystem recieves a large input of a limiting nutrient - for example, runoff from heavily fertilized fields - the result is oftan an immediate increase in the amounth of algaue and other producers.
Water Cycle
Moves between the ocean, atmosphere, and land. has the processes of evaporation, transpiration, condensation, and precipitation.
Carbon Cycle
contains biological processes, geochemical processes, mixed biogeochemical processes, and human activities.
Nitrogen Cycle
Cycles through soil, the atmosphere, and the tissues of living organisms. Its main reservoir is the atmosphere. Contains denitrification,.
Phosphorus Cycle
Cycles among the land, ocean sediments, and living organisms. does not have an atmosphere reservoir.
IN a food cahin where a snake eats a frog that ate an insect that ate a plant, the snake is a...
third-level consumer
what are all the levels of organization?
ISPCEBB
how does water return to Earth from the atmosphere?
precipitation
What element helps build amino acids?
Nitrogen
what element is needed for a genetic code?
Phosphorus
What is taken from the atmosphere during photosynthesis?
Carbon Dioxide
primary productivity
the rate at which organic matter is created by producers
Types of Heterotrophs
Herbivores
carnivores
Omnivores
Decomposers
Examples of Decomposers
Bacteria Fungi
scavengers
Animals that consume the carscasses of other animals that have been killed by predators or have died of other causes
Examples of Scavengers
Vultures
crabs
Hyena
Crow
Examples of Ecological Pyramids
Pyramid of Numbers
Energy Pyramid
Biomass Pyramid
What different levels of organization do ecologists study?
The study of ecology ranges from the study of an individual organism to populations, communities, ecosystems, biomes, and finally the entire biosphere
what methods are used to study ecology?
observing, experimenting, and modeling
where does the energy for life processes come from?
The sun/chemical compounds
How does energy flow through living systems
Energy flows through an ecosystem in a one-way stream, from primary producers to various consumers.
How efficient is the transfer of energy among organisms in an ecosystem
10% is transferred to each tropic level
How does matter move among living and nonliving parts of an ecosystem?
unlike the one way flow of energy, matter is recycled within and between ecosystems
How are nutrients important in living sytems
Every living organism needs nutrients to build tissues and carry out essential life functions. Like water, nutrients are passed between organisms and the enviroment through biogeochemical cycles.