Living Things in an Environment
What are the levels of organization for an ecosystem from smallest to largest?
Organism -> population -> community -> ecosystem
What are biotic factors?
Things that are or were living in an environment.
What is a producer?
An organism that makes its own food.
What is a consumer?
An organism that eats other organisms for energy.
What does it mean if a system is closed?
Matter cannot enter or exit
What is evaporation?
The process by which molecules at the surface of liquid water absorb enough energy to change to a gas.
What are resources?
Resources are what an organism needs to live, grow, and reproduce.
What are abiotic factors?
The nonliving things in an environment.
What is a decomposer?
An organism that breaks down waste to redistribute the nutrients.
What do most producers/ecosystems get their energy from?
Sunlight
What is condensation?
The process of a gas changing to a liquid.
What is precipitation?
Condensed water vapor.
What do limiting factors do to a population?
They cause the population to decrease.
How does a population remain stable?
The birth rate and death rate are the same.
What is the difference between a carnivore and an herbivore?
A carnivore eats only animals/meat, and an herbivore eats only plants.
Why is it better to use a food web rather than a food chain?
A food web demonstrates every pathway of energy transfer while a food chain only demonstrates one pathway.
What is the Law of Conservation of Mass?
Matter is neither created nor destroyed during any chemical or physical change.
What is the Law of Conservation of Energy?
When one form of energy is transformed to another, no energy is lost in the process.
How does a population decrease? Give both answers
Organisms emigrate from the population
The death rate is greater than the birth rate
How does a population increase? Give both answers.
Organisms immigrate into the population
The birth rate is greater than the death rate
About how much energy is transferred from level to level?
10%
What is a nickname that a decomposer has?
Nature's recycler
What are some examples of precipitation?
What are the three processes of the water cycle?
Condensation, precipitation, and evaporation.
Define a habitat
The environment that provides the things that an organism needs to live, grow, and reproduce (resources).
What is the formula for population density?
Population density = number of individuals/unit area
An omnivore would typically be a first-level consumer.
Why is the energy pyramid in the shape of a pyramid instead of a box or a circle?
To demonstrate that each level has less and less energy. The farther up the pyramid, the less energy you receive from the original producer.
What is it called when producers take in carbon dioxide from the air to make food and release oxygen?
Photosynthesis
Why is nitrogen fixation necessary?
Most organisms cannot use free nitrogen gas.