Unit 1

Ecosystem

All living and nonliving things in an area, including plants, animals, rocks, soil, water, and air.

Population

Group of individuals of the same species; for example, a herd of elk.

Community

All living organisms in an area interacting with each other.

Biome

The plants and animals found in a given region, determined by climate, such as a tropical rainforest.

Symbiosis

Any close and long-term interaction between two organisms of different species.

Predation

One organism uses another for an energy source, often leading to a positive impact for one and a negative impact for the other.

Mutualism

A type of symbiotic relationship that benefits both organisms involved.

Parasitism

A relationship where one organism (the parasite) benefits at the expense of another organism (the host), causing harm.

Herbivory

The act of animals eating plants for energy, such as a rabbit eating lettuce.

Competition

Organisms fighting over resources such as food or shelter, which can limit population size.

Carbon Cycle

Movement of carbon-containing molecules between sources and sinks, including processes like photosynthesis and respiration.

Nitrogen Fixation

The process of converting nitrogen gas (N2) into biologically available forms such as ammonia (NH3) or nitrate (NO3).

Phosphorous Cycle

Movement of phosphorus atoms and molecules between sources (mainly rocks) and sinks, which is a slow process compared to carbon and nitrogen cycles.

Primary Productivity

Rate at which solar energy is converted into organic compounds via photosynthesis over a unit of time.

Trophic Levels

Different levels in a food chain or web, where energy is passed from producers to various consumer levels.

10% Rule

In trophic pyramids, about 10% of energy from one trophic level is transferred to the next level; 90% is used or lost as heat.

Wetland

Area with soil submerged or saturated in water for part of the year, providing habitat for various plants and animals.

Eutrophication

Excess nutrients in aquatic ecosystems causing algae blooms that block sunlight and lead to decreased oxygen levels.

Biogeochemical Cycles

Natural processes that recycle nutrients in different forms from the physical environment to organisms and back.

Salinity

The amount of salt in water, which determines the types of organisms that can survive.

Photosynthesis

The process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose.

Cellular Respiration

Process where cells break down glucose into energy, releasing carbon dioxide as a byproduct.

Nutrient Limitation

The concept that the availability of nutrients, such as nitrogen or phosphorus, can limit ecosystem productivity.

Energy Flow in Ecosystems

The transfer of energy from one trophic level to another, with energy diminishing as it moves up the levels.

Herbivores

Organisms that eat plants, serving as primary consumers in the food web.

Tertiary Consumers

Carnivores that eat secondary consumers, often at the top of the food chain.

Aquatic Biomes

Ecosystems found in bodies of water, characterized by salinity, depth, flow, and temperature.