Earth's atmosphere expands from the earth's surface to an altitude of 10.coom
Gases produced

Carbon dioxide
Methane
Ammonia
Plant life appeared

Carbon dioxide increased
Oxygen increased
Methane decreased
Ammonia decreased
For the past 600 million years

Significant changes have occurred in the atmosphere
Carbon dioxide decreased
Oxygen increased
Methane decreased
Ammonia decreased
Hydrogen increased
Carbon (atmospheric) oxygen sediments Shells
Carbon dioxide

Carbonates precipitated out, reducing the amount of COâ‚‚ in the atmosphere
Volcanoes actively release series is just.
One memory of how Earth's atmosphere formed...
Volcanic activity

Releases gases into the atmosphere
Carbon dioxide increased
Oxygen increased
Nitrogen increased
Flood events

Can change the atmosphere
Oxygen increased
Carbon dioxide decreased
Methane decreased
Ammonia decreased
Algae first produced oxygen about 2.7 billion years ago
Oxygen appeared in the atmosphere due to plant and algae photosynthesis
Plant and algae photosynthesis used up carbon dioxide from the atmosphere
Carbon dioxide was also removed from the atmosphere as it was used to form sedimentary rocks and fossil fuels that contain carbon
The amount of CO2 has nearly stayed the same for 200 million years due to the carbon cycle
The percentage of O2 increased as plants photosynthesized
The earth's atmosphere is a mixture of gases
Ecosystem

Distinct self supporting system of organisms interacting with each other and the environment
Individual

A single member of a species
Population

A particular species in the same area at a certain time
Community

Multiple populations living and interacting in an ecosystem
Habitat

Where an organism lives at any one time
Producers
Plants which photosynthesize to produce food
Consumers
Animals that eat plants or other animals
Decomposers

Organisms that break down dead material and help to recycle nutrients by saprotrophic nutrition (extracellular enzymatic digestion)
Biodiversity

Amount of variation shown by species
Species richness
Abundance of species and even distribution
Biotic factors

May continue until there are too few members of the lesser adapted species to breed successfully
Pyramid of energy
Illustrates the amount of energy contained within the biomass, area of each box represents the quantity of energy, wide base, as you move up the energy decreases, only 10% of the energy is passed on
Energy transfer
1. Producers use glucose from respiration to produce their own biomass
2. Primary consumers eat producers, they digest the biomass and use the chemical energy to increase or sustain their own biomass
3. Only the energy from assimilation remains with the organism to be passed on
Availability of food
More food means more organisms can survive and reproduce, increase in population size
New predators

In balanced ecosystems, predators catch enough prey to survive but not many that they wipe out the population, if a new predator is introduced ecosystem may become unbalanced
New pathogens

If a new pathogen enters an ecosystem, the population will have no immunity or resistance, population may decline or wipe out
Competition
If 2 species compete for the same resource and one is better adapted then that species will outcompete the other