is the transfer of energy from one organism to another in an ecosystem

This is a natural system altered by men through agricultural activity.

Interconnected food chains are illustrated in a model called

show the flow of energy from plant to animal and from animal to animal.

The first trophic level includes organisms that are called

The second trophic level of organisms gets energy by eating other organisms.

is a model that shows the loss of energy from one trophic level to another

break down dead or decaying consumers and producers via chemical reactions and use the energy released from rearranging those molecules for growth and development.

are chemicals required for plant and animal growth and other life processes

describes the breakdown of organic wastes and dead organisms.

is an essential component of cells and life-sustaining chemical reactions.

describe the flow of nutrients in and out of stores as a result of biotic and abiotic processes

plants and animals obtain energy by converting carbohydrates and oxygen (O2) into carbon dioxide and water.

is a chemical reaction that converts solar energy and atmospheric carbon dioxide gas (CO2) into chemical energy.

Dissolved carbon dioxide is stored in oceans. Marine organisms store carbon-rich carbonate (CO3 2- ) in their shells, which eventually form sedimentary rock.

Nitrogen gas is converted into nitrate (NO3 - ) and ammonium (NH4 +), compounds that are usable by plants.

is an important component of DNA and proteins

occurs mainly through nitrogen-fixing bacteria, and when lightning strikes in the atmosphere.

Ammonium is converted into nitrate and nitrite (NO2- ) through the work of nitrifying bacteria.

Denitrifying bacteria convert nitrate back into atmospheric nitrogen

Useable forms of nitrogen are taken up by plant roots and incorporated into plant proteins.

through chemical or physical means—breaks down rock, releasing phosphate into the soil from longer-term stores.

carries energy to cells.

Nutrient cycles

is a major problem that is yet to be solved.

Causes of Pollution