Energy flow Flashcards
(28 cards)
Producers
Organisms that make food. Also called autotrophs
Consumers
Organisms that use food by eating producers or other consumers. Also called heterotrophs
What is the 10% rule
Approximately 10% of the energy at one trophic level can be used by consumers at the next trophic level
What happens to the 90%?
Approximately 90% of the acquired energy is lost between trophic levels
How is most of the energy lost between trophic levels?
As heat into the atmosphere.
When an organism (like a caterpillar eating a leaf) takes in energy, what happens to it?
Some energy is not assimilated (passes through as feces). Of the assimilated energy, some is used for cellular respiration, and some is used for growth (new biomass) or development
What percentage of the original energy from the sun captured by an organism is used for cellular respiration?
Approximately 60%
What is the energy used for growth and development and available to be passed on if eaten called?
This energy represents Ecological Efficiency
Roughly how much chemical energy from photosynthesis reaches a tertiary consumer?
Approximately 0.1%
Define Trophic Level.
Each step in a feeding relationship
What are Ecological Pyramids used for?
They are graphic representations of the relative amounts of energy, biomass, or number of organisms at each trophic level. They show how energy flows through ecosystems
What are the three main types of Ecological Pyramids?
Energy Pyramid, Biomass Pyramid, and Pyramid of Numbers.
What does an Energy Pyramid represent?
Compares the energy used by organisms at different trophic levels. Clearly shows energy loss (up to 90%) between tiers. Only 10% is transferred.
Define Biomass.
The total dry mass of organisms in a given area or at a particular trophic level. The total combined weight of any specified group of organisms.
What does a Biomass Pyramid represent?
Represents the dry mass of all organisms in each level. Typically shows a sharp decrease in total dry weight at successively higher trophic levels.
How can biomass be calculated?
Number of organisms x the weight of an average individual.
What does a Pyramid of Numbers represent?
Shows the number of individual organisms at each trophic level.
What is generally required at the producer level to support higher trophic levels in a pyramid of numbers?
A vast number of producers are required to support even a few top-level consumers.
How does the movement of matter differ from the flow of energy in ecosystems?
Matter cycles through ecosystems, while energy flows in one direction.
What are some major places carbon is found (reservoirs)?
Atmosphere (CO2), plants, animals, fossil fuels, soils, sediments.
What are some key processes in the Carbon Cycle?
Photosynthesis (takes up CO2), Cellular Respiration (releases CO2), Combustion (like burning fossil fuels), and Decomposition.
Why is Nitrogen important in biological molecules?
It’s part of DNA, RNA, and amino acids (proteins). Its availability often limits plant growth.
What percentage of the atmosphere is Nitrogen gas (N2)?
Approximately 78%.
What are the main processes in the Nitrogen Cycle mentioned?
Nitrogen fixation, Mineralisation (ammonification), Nitrification, and Denitrification.
