Units 1-4 Study Set Flashcards
Scientific method
- Make Observations
- Background research/Ask a question
- Form a hypothesis
- Design an Experiment
- Gather/Present Data
- Analyze Data/Draw Conclusions
Independent variable
- A variable that stands alone and isn’t changed by the other variables you are trying to measure
- The cause of the experiment
- X-axis
Dependent variable
- What you measure in the experiment and what is affected during the experiment
- The effect of the experiment
- Y-axis
Energy
The ability to do work or transfer heat
Joule
The amount of energy used when a 1-watt electrical device is turned on for 1 second
Energy conversions
- energy = power × time
- power = energy ÷ time
Electromagnetic radiation
A form of energy emitted by the Sun that includes, but is not limited to, visible light, ultraviolet light, and infrared energy
Photon
A massless packet of energy that carries electromagnetic radiation at the speed of light
Potential energy
Energy that is stored
Chemical energy
Potential energy stored in chemical bonds
Kinetic energy
Energy of motion
Temperature
The measure of the average kinetic energy of a substance
1st Law of Thermodynamics
Energy is neither created nor destroyed, but may be converted from one form to another
2nd Law of Thermodynamics
When energy is changed from one form to another, some useful energy is always degraded to lower quality energy
Entropy
The amount of disorganization present in a system
Open system
A system in which exchanges of matter or energy occur across system boundaries
Closed system
A system in which matter and energy exchanges do not occur across boundaries
Input
An addition to the system
Output
A loss from the system
Steady state
A state in which inputs equal outputs, so that the system is not changing over time
Negative feedback loop
A system responds to a change by returning to its original state, or by decreasing the rate at which the change is occurring
- Helpful
Positive feedback loop
Change in a system is amplified
- Undesirable
Ecosystem
○ Some have well-defined boundaries, while others do not
* The biotic and abiotic components of
an ecosystem provide the boundaries
that distinguish one ecosystem from
another
* Some ecosystems are very small
* Each ecosystems interact with each
other through the exchange of
energy and matter
Biosphere
The region on our planet where life resides
Predator
Eats other organisms
Prey
Organisms eaten by other organisms
Symbiosis
a close, long-term interaction between two species in an ecosystem
Mutualism
Both organisms benefit
Commensalism
One organism benefits, one organism neither benefits nor is harmed
Parasitism
One organism benefits and one is harmed
Competition
Organisms compete when they seek the same limited resource
Interspecific competition
Members of a different species compete for the same resource
Intaspecific competition
Members of the same species compete for resources
Producers/autotrophs
Organisms that use the Sun to produce usable energy
Photosynthesis
The use of solar energy to convert carbon dioxide and water into glucose and oxygen
Cellular respiration
A process by which cells unlock the energy of chemical compounds
Aerobic respiration
The opposite of photosynthesis, where oxygen and glucose are converted into energy, carbon dioxide, and water
Anaerobic respiration
- Cells convert glucose into energy in the absence of oxygen
- does not provide as much energy
Consumers/heterotrophs
Organisms incapable of photosynthesis who must obtain their energy by consuming other organisms
Herbivores/primary consumers
Consumers that eat producers
Carnivores
Consumers that eat other consumers
Secondary consumers
Carnivores that eat primary consumers
Tertiary consumers
Carnivores that eat secondary consumers
Trophic levels
The success of organisms consuming one another
Food chain
The sequence of consumption from producers through tertiary consumers
Food web
- A complex model of how energy and matter move through trophic levels
- All species in an ecosystem are connected to one another
Omnivores
Organisms that operate at several trophic levels
Scavengers
Organisms that consume dead animals
Detritivores
Organisms that break down dead tissues and waste products into smaller particles
Decomposers
The fungi and bacteria that complete the breakdown process by converting organic matter into small elements and molecules that can be recycled back into the ecosystem
Gross primary productivity (GPP)
- A measure of the total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time
- Indicates the total amount of energy captured by producers
Net primary productivity (NPP)
- The energy captured minus the energy respired by producers
- The greater productivity of an ecosystem, the more primary consumers can be supported
Biomass
The total mass of all living matter in a specific area
Standing crop
- The amount of biomass present in an ecosystem at a particular time
- not the same as productivity
Ecological efficiency
- The proportion of consumed energy that can be passed from one trophic level to another
- 10% average across all ecosystems
10% rule
Only 10% of energy from one trophic level is able to move up to the next
Trophic pyramid
A method of representing the distribution of biomass among trophic levels
Biogeochemical cycles
The movements of matter within and between ecosystems
Hydrologic cycle
The movement of water through the biosphere
Evapotranspiration
- The combined process of evaporation from land surfaces and transpiration from plants
- An important component of the hydrologic cycle as it returns water vapor back into the atmosphere
Transpiration
The process by which plants release water vapor into the atmosphere through their leaves
Steps of the hydrologic cycle
- Water evaporates from the Earth and into the atmosphere: Heat from the sun causes water to turn into water vapor and rise into the atmosphere, while plants can release water from their leaves.
- Once the water has evaporated into the atmosphere, it comes back down to the Earth in the form of precipitation (rain, snow, hail/sleet, etc)
What happens to water when it returns to Earth?
- Surface runoff
- Percolation
- Photosynthesis
Surface runoff
- Water that flows over the land surface rather than infiltrating into the ground
- Occurs when rainfall or snowmelt exceeds the soil’s ability to absorb it or when the ground is already saturated
Percolation
- The process of water seeping through soil or rock layers and moving downward into the ground
- The water will be absorbed by the ground and will become part of the Earth’s groundwater stores
Human impacts on the hydrologic cycle
- Clear-cutting forests can lead to soil erosion and flooding
- Erosion and heat waves can become extreme and cause harm to humans and other ecosystems
- Pollution of water and climate change caused by human presence on Earth depletes and dirties water supply
Carbon cycle
The movement of carbon around the biosphere
Photosynthesis and the carbon cycle
- When photosynthesis occurs, CO2 from human activity and other natural processes is regulated and converted to oxygen, essential for the Earth’s health and human survival
- Since CO2 is a greenhouse gas, preventing its overabundance is important so as to mitigate the effects of climate change
- The CO2 that plants retain is kept in their plant tissue, which eventually dies
- Decomposers will process that matter, leaving all carbon in the soil or nearby surroundings
Carbon sinks
Natural or artificial reservoirs that absorb and store carbon dioxide from the atmosphere, helping to mitigate climate change
Carbon exchange
The ocean absorbs some CO2 from the atmosphere, and it releases roughly the same amount of CO2 back into the atmosphere
Sedimentation
- The process by which particles settle out of a fluid (such as water) and accumulate at the bottom, forming layers of sediment over time
- The CO2 combines with calcium ions in the water to form calcium carbonate, which sinks to the bottom of the ocean and accumulates
- If left undisturbed, it can cause accumulation of carbon, but upon disturbance that carbon is reintroduced to the atmosphere and continues its journey through the carbon cycle
Fossil fuels
Natural resources formed from the remains of ancient plants and animals that have been buried and subjected to heat and pressure over millions of years
Macronutrients
One of six key elements that organisms need in relatively large amounts; nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur
Nitrogen cycle
The movement of nitrogen around the biosphere
Nitrogen fixation
Allows nitrogen gas to be converted into a form that can be used by plants and animals, such as ammonia (NH3) or nitrate (NO3)
Nitrification
The process by which ammonia (NH3) is converted into nitrite (NO2-) and then into nitrate (NO3-), primarily carried out by bacteria
Assimilation
- The process in which plants and animals take up nutrients from their environment and incorporate them into their own tissues for growth and development
- This nitrogen can be synthesized by consumers, or it can run into the ocean, providing aquatic ecosystems with enough nitrogen
- When these organisms die, decomposition occurs and organic nitrogen present in these organisms through the nitrogen cycle reverts back into ammonium