Biodiversity
What determines whether an ecosystem is healthy?
Number/variety of organisms in an area
What is the bottom level of a food web called?
Producers/decomposer
What two processes are involved in the carbon/oxygen cycle
Cellular respiration and photosynthesis
If one organism benefits and the other dies
Predation
What is the difference between a mass extinction and a background extinction?
Mass= Multiple species at once
Background= one species over a long period of time
What are three reasons that Cheetahs are going extinct
Habitat loss, Low genetic diversity, environmental changes, over hunting
If an animal is a omnivore it is most likely what level of a food web?
secondary consumer
What diatom is free nitrogen?
N2
parasitism
How do trees provide all four services?
Cultural - leaf viewing
Provisional- wood for building
support- Oxygen
regulatory- Clean/filter water
The specific role an animal plays in their ecosystem
Niche!
What does a decomposer do in an ecosystem?
Break down waste in the ecosystem
What are the two ways to fix free nitrogen?
Lightning strike and root nodule bacteria
Mutualism
Bioremediation (eat oil)
How can humans negatively affect biodiversity in an area?
Invasive species
removing keystone species
pollution
urbanization/industrialization
What are three ways that carbon can be added back into the atmosphere?
Respiration, Burning wood, fossil fuel burning.
If one organism benefits and the other is unaffected
Commensalism
Explain the steps needed for primary succession
Pioneer species on rock layer
lichen excrete acidic compounds breaking down rock
small soil layer allows for primitive plants
plants improve soil by decomposing over hundreds of generations
mature community formed
Pick a keystone species and explain its role in the environment
ex: Elephant. Clears old trees for young trees to get sunlight. Allows smaller animals to eat the fruit left behind when elephants shake the big trees.
How much energy is lost as you move one level up a food web?
1/10 of the energy
What are the 4 steps of the water cycle
evaporation, condensation, precipitation, runoff
When two organisms fight for resource availability
Competition
What are three limiting factors on a population
Shelter
food
water
climate
disease