22: Ecosystems Capture Energy and Cycle Chemicals Flashcards
Module 4, Lesson 3
____ describes how all the species in a community interact with the physical environment to obtain the resources they need.
Ecosystem ecology
List the three components of an ecosystem.
- Abiotic/nonliving
- Producers
- Consumers
____ are cycled between the biotic and abiotic components of an ecosystem.
Nutrients
The ultimate source of energy in most ecosystems is…
Solar energy
True or false:
The exact boundaries of an ecosystem are not fixed.
True
____ describe the processes by which nutrients flow between living and nonliving organisms in a cyclic path.
Biogeochemical cycles
(nutrient cycles)
Water is synthesized in ____ and broken down in ____.
Cellular respiration ; photosynthesis
True or false:
The water synthesized in respiration and broken down in photosynthesis influences the amount of water that is cycled.
False
The rates of these two processes are equal, so they don’t influence the water cycle
____ occurs when surface water is taken up into the atmosphere.
Evaporation
____ occurs when water is taken up into the atmosphere from plant surfaces.
Transpiration
In vegetative landscapes, most of the water that reaches the atmosphere comes from…
Transpiration
____ occurs when water vapor is converted into liquid form in the atmosphere.
Condensation
____ occurs when water falls back to earth in a liquid or froze form.
Precipitation
____ occurs when water travels downwards through the spaces between rocks and soil particles.
Percolation
Water on land, which comprises about 95% of Earth’s freshwater, is called…
Groundwater
A(n) ____ is a permeable underground layer where water is found.
Aquifer
The upper layer of groundwater is called the…
Water table
Water in the ____ can flow into streams and be taken up by plant roots.
Water table
The ____ of groundwater is only accessible by wells.
Lower layer
List the steps of the water cycle in order, beginning with evaporation.
- Evaporation / Transpiration
- Condensation
- Precipitation
- Percolation
Carbon is a vital nutrient for living things because it…
Forms the basis of the organic compounds necessary for life
List two major sources of carbon.
- Carbon dioxide
- Bicarbonate
Atmospheric carbon dioxide can dissolve in water and be converted into…
Bicarbonate
____ is the process by which plants and photosynthetic organisms take in atmospheric CO2 and use it to make organic compounds.
Carbon fixation
The process of carbon fixation occurs during…
The light-independent reactions of photosynthesis
Carbon compounds can be consumed by animals and used for…
Nutrients
During cellular respiration, carbon compounds are broken down to…
Release energy
Cellular respiration releases ____ as a byproduct.
Carbon dioxide
During the process of ____, dead organic matter is broken down, which releases carbon dioxide.
Decomposition
The production of ____ by anaerobic prokaryotes helps return carbon dioxide to the atmosphere.
Methane
Carbon compounds can be stored for long periods of time as…
Fossil fuels
Humans have created an imbalance in the carbon cycle due to…
Our rapid combustion of fossil fuels
List four ways that carbon dioxide can be returned to the atmosphere.
- Respiration
- Decomposition
- Methane
- Fossil fuel combustion
____ is necessary for the synthesis of proteins and nucleic acids, and is the limiting nutrient in many ecosystems.
Nitrogen
True or false:
Plants and animals cannot use atmospheric nitrogen.
True
Plants acquire nitrogen by taking up ____ from the soil.
Nitrate and ammonia
Animals use ____ as the source of amino acids for protein synthesis.
Proteins in food
Some prokaryotes can perform ____, which converts atmospheric nitrogen to ammonia.
Nitrogen fixation
True or false:
High-energy abiotic nitrogen fixation can occur via events such as lightning and cosmic radiation.
True
In the soil, an excess of hydrogen ions allows ammonia to be rapidly converted into…
Ammonium
____ occurs when ammonium or ammonia is converted into nitrate.
Nitrification
Nitrogen in waste and dead organic matter is released as ____ during decomposition.
Ammonia and nitrate
____ is the process by which nitrogen is returned to the atmosphere.
Denitrification
Denitrification is carried out in anaerobic conditions by…
A group of specialized bacteria
Humans have altered the nitrogen cycle through…
Our use of nitrogen fertilizers
The phosphorus cycle is unique because…
There is no gaseous phase
____ is necessary to produce phospholipids, ATP, and nucleic acids.
Phosphorus
____ is released into the soil during weathering of rocks.
Phosphate
Plant roots can acquire phosphate from…
The soil
Animals gain phosphate from…
The food they consume
Decomposers release phosphate from…
Dead organic matter
If phosphate is not quickly taken up by plant roots, it can be…
Washed away by streams and rivers
Humans have impacted the phosphorus cycle by…
Adding phosphorus to fertilizers
A ____ is an element that is in short supply relative to the need for it in an ecosystem.
Limiting nutrient
The rate at which the limiting nutrient is available for use is determined by…
The rate at which it is cycled
In many ecosystems, the limiting nutrients are…
Nitrogen and phosphorus
In many ocean ecosystems, the limiting nutrient is…
Iron
Iron is often a limiting nutrient in ocean ecosystems because…
Phytoplankton need iron to perform photosynthesis
True or false:
Energy can be recycled in an ecosystem.
False
True or false:
Energy always flows in only one direction through an ecosystem.
True
The first law of thermodynamics states that…
Energy cannot be created or destroyed, but can change forms
The second law of thermodynamics states that…
With every energy conversion, some is released as heat energy
True or false:
Living organisms cannot use heat energy for their cellular energy needs.
True
What can living organisms use heat energy for?
Maintaining body temperature
Because of ____, heat energy is constantly released into the environment as unusable energy.
The second law of thermodynamics
The energy in an ecosystem is constantly being lost as ____ and resupplied by the ____.
Heat ; Sun
A ____ is a group of organisms that fill the same role with regards to their primary food source.
Trophic level
(feeding level)
Organisms in the first trophic level are…
Autotrophs / producers
Most organisms in the first trophic level are ____, which use solar energy to make organic compounds via photosynthesis.
Photoautotrophs
Some organisms in the first trophic level are…
Chemoautotrophs
Organisms in all higher trophic levels are…
Heterotrophs / consumers
True or false:
An organism will only feed from the trophic level directly below it.
False
Some can feed from multiple trophic levels
The organisms in the second trophic level are ____, and gain most of their energy from consuming organisms in the first trophic level.
Herbivores
The organisms in the third trophic level are ____, and gain most of their energy from consuming organisms in the second trophic level.
Primary carnivores
Organisms in the fourth trophic level are ____, and gain most of their energy from consuming organisms in the fourth trophic level.
Secondary carnivores
____ are the organisms in the trophic level that feed on dead organic matter (detritus).
Decomposers and detritovores
True or false:
Decomposers and detritovores feed on detritus from all trophic levels.
True
____ ingest dead organic matter.
Detritovores
____ are bacteria and fungi that secrete enzymes to break down dead organic compounds.
Decomposers
____ is all of the photosynthesis by all of the primary producers in an ecosystem over a set time period.
Gross primary productivity
(GPP)
The productivity of the primary producers is called…
Primary productivity
____ is the rate at which all organisms in the trophic levels synthesize new organic matter.
Productivity
The “set time period” used to calculate GPP is normally…
One year
____ is the rate of energy use by organisms for their metabolic needs.
Respiration
(R)
____ is the energy left over after producers use energy for their metabolism.
Net primary productivity
(NPP)
____ is the amount of energy that the autotrophs can invest into their growth and reproduction.
Net primary productivity
____ describes the NPP ingested by the next trophic level.
Secondary productivity
Each trophic level can only use about ____% of the energy available to the level below it.
10%
____ describes the energy invested into growth and reproduction by the consumers.
Secondary production
The next trophic level can only use the energy that the one below it invested into…
Growth and reproduction
Primary producers only convert about ____% of solar energy into chemical energy.
1%
The total amount of energy available for the ecosystem is determined by the…
Primary productivity
In each trophic level, some energy is lost when it is diverted to…
Heat and waste
Energy is passed between trophic levels in the form of…
Chemical bond energy
The number of trophic levels in an ecosystem is limited by the…
Decline of energy available to each trophic level
Eventually, all the chemical bond energy in an ecosystem will become…
Heat
____ are used to illustrate relationships between trophic levels.
Ecological pyramids
The width of each box on an ecological pyramid represents…
The magnitude of the ecological property being described
List three properties that we can construct ecological pyramids for.
- Energy flow
- Biomass
- Numbers
An ecological pyramid for ____ can never be inverted.
Energy flow
(because energy is always lost in higher trophic levels)
An ecological pyramid for ____ can be inverted or upright.
Biomass
(because the amount of biomass in each level can vary)
An ecological pyramid for ____ is usually upright.
Numbers
(because there are generally more producers than consumers)
A ____ occurs when an upper trophic level influences 2 or more lower levels.
Trophic cascade
The effects of a trophic cascade are described as…
Top-down effecrs
True or false:
A trophic cascade can increase or decrease biomass depending on the trophic level.
True
The effects of introducing fish on invertebrates and algae is an example of a…
Trophic cascade
____ occur when the amount of primary productivity affects the upper trophic levels.
Bottom-up effects
When there is enough producer biomass to support herbivores, the producer biomass..
Does not increase
When there is enough herbivore biomass to support carnivores, the producer biomass…
May increase again
True or false:
Larger islands tend to support more species than smaller islands.
True
Larger islands can support more species due to the effects of ____ and ____ on the likelihood of species colonization and extinction.
Geographic area and isolation
Over time, the colonization rates ____ and the extinction rates ____.
Decrease ; increase
The ____ suggest that the number of species on an island is a dynamic equilibrium between colonization and extinction.
Equilibrium model
The rate of colonization and extinction on an island is impacted by the…
Island’s size and its distance from the mainland
Extinction rates are higher on ____, because…
Smaller islands ; population sizes are smaller to begin with
Colonization rates are higher on ____, because…
Islands closer to the mainland ; it is easier for species to reach the island
At equilibrium, which type of islands have the highest species richness?
Large islands near the mainland
