The study of nature and the facts about environment.

All the social, economical, physical and chemical factors that surrounds man.

All abiotic and biotic components around man; all living and non-living things surrounds man.

A threat to life, health, property, or ecosystems, i.e., it involves something that could potentially be harmful.

Combustion of Fossil fuels, industrial effluence, pesticides heavy metals.

Radioactive and UV radiations, Global warming, Chlorofluro carbons, Noise etc.

Bacteria, Viruses, Parasites

A natural functional ecological unit comprising of living organisms and their non-living environment that interact to form a stable self-supporting system.

A community or group of living organisms that live in and interact with each in a specific environment.

Include the living beings of the ecosystem.

Include the non-living physical beings.

Branch of biology that deals with the relations of organisms to one another and to their physical environment.

Study of the distribution and abundance of organisms, the flows of energy and materials between abiotic and biotic components of ecosystem.

How the organisms respond to the atmosphere, topography, soil, and climate and water availability.

Make food, plants, algae.

Eat other organisms.

Eat dead organic matter; bacteria and fungi.

Eats plants.

Meat eaters: eat herbivores.

Feed on carnivores.

Eat plants/animals.

The first step in the production of energy for living things.

Chemical reaction where green plants use water and carbon dioxide to store the sun’s energy in glucose.

Is stored in glucose.

Is stored as starch in plants.

The transfer of energy and nutrients through a series of organisms with repeated process of eating and being eaten.

Plants by photosynthesis convert solar energy into __.

Interlocking pattern of several interlinked food chains.

An ecosystem linking of feeding habit relations.

A graphical representation that shows the relative amounts of energy or matter contained within each tropic level in a food chain or a food web.

Shows the relationship between consumers and producers at different tropic levels in an ecosystem.

Shows the relative number of individual organisms at each tropic level.

Represents the total dry mass (in grams per square meter of area) of all the organisms in each tropic level at a particular time.

Represents rate of energy flow and/or productivity at successive tropic levels. They are always UPRIGHT.

Is crucial for all organisms o Nucleic acids o Proteins o Chlorophyll.

78% in Atmosphere.

Is very stable and must be broken apart by organisms, combined with other atoms into a usable form.

Conversion of N2 to NH3.

Combustion, volcanic action, Lightning, Industrial processes (making fertilizer). Bacteria (Azotobactor, Clostridium, Nostoc etc.)

Conversion of NH3 to NO3.

Soil bacteria convert in a two step process.

Roots absorb NH3, NH4, or NO3 and incorporate them into nucleic acids and protein.

Amino acids and nucleotides are broken down into waste products NH3 or NH4.

The reduction of NO3 to N2. --ing bacteria return some of the nitrogen to the atmosphere.

The circulation of oxygen in various forms through nature free in the air and dissolved in water.

Is second only to nitrogen in abundance among uncombined elements in the atmosphere.

Photosynthesis removes __ from the abiotic environment (fixes it into organic molecules).

It moves through food chain through consumption of one organisms by another.

The only cycle that does not have a gaseous state.

Is released from rocks and sediments through the action of erosion.

Is absorbed by plants and incorporated into nucleic acids, phospholipids and ATP.

Is released to the soil again by decomposers.

A change in the community in which new populations of organisms gradually replace existing ones.

Occurs where there is no soil, e.g. after a volcanic eruption or a glacial retreat.

Community development in the areas that were previously occupied by another community.

It occurs after a disturbance. E.g., loss of trees after disease, fire or wind, deforestation etc.

Is an area with a high density of trees.

World's total land area is __ million hectares - (Source: FAO; 1989) of which total forests account for about __% of the world's land area.

Are of great concern from the environmental point of view.

These are Herbivores which feed directly on producers.

These are carnivores and feed on primary consumers.

These are secondary carnivores and feed on secondary consumers.

These include wide variety of saprotrophic micro-organism.

These include basic inorganic & organic compounds present in the soil & atmosphere.

Are areas where the vegetation is dominated by grasses and other herbaceous (non-woody) plants.

Occupy about 24% of the earth's surface.

Occur in regions too dry for forests and too moist for deserts.

The highest abundance & greatest diversity of large mammals are found in these ecosystems.

A landscape or region that receives almost no precipitation.

Areas with an average annual precipitation of less than 250 millimeters per year.

It occupies about 17% of the earth's surface.

Are characterized by hot days & cold nights.

Are characterized by scanty flora & fauna.

Soils of this ecosystem often have abundant nutrients but little or no organic matter.

Deals with biotic community present in water bodies.

Freshwater ecosystems cover __% of the Earth's surface and contain __% of its total water.

Freshwater ecosystems contain __% of the world's known fish species.

Slow-moving water, including Pools, Ponds, and Lakes.

Rapidly-moving water, for example Streams and Rivers.

Areas where the soil is saturated with water or inundated for at least part of the time.

A place where living organisms not only live but interact with biotic & abiotic components.

Are often exposed to tremendous anthropogenic pressure which significantly affects the system.

Are usually big standing freshwater bodies.

A shallow water zone.

An open water zone where effective penetration of solar light takes place.

A deep water zone where light penetration is negligible.

Are among the Earth's aquatic ecosystems. They include: Oceans, Estuaries and Lagoons, Mangroves and Coral reefs, the Deep sea and the Sea floor.

These are the gigantic reservoirs of water covering approximately __% of the Earth's surface (an area of some 361 million square kilometers).

These ecosystems are different from freshwater ecosystem mainly because of its salty water.