Science 8: Chapter 1 - Cycles of Nature Flashcards

This set of vocabulary flashcards covers the flow of energy, the path of nutrients, and the specific mechanisms of the water, carbon-oxygen, and nitrogen cycles from Science 8, Chapter 1.

Biosphere

The region where energy flows in a one-way path and nutrients move through biotic and abiotic components.

Producer

An autotroph or photosynthesizer, such as cyanobacteria, phytoplankton, or vegetabilia, that serves as the base of the energy-food pyramid.

Primary Consumer

An herbivore that eats producers and their products.

Secondary Consumer

A carnivore that eats herbivores.

Tertiary Consumer

A carnivore that eats other carnivores.

Decomposers

Organisms like bacteria, fungi, and earthworms (detritivores) that break down dead organic matter and return substances to the environment.

10% Rule

The principle stating that approximately $10\%$ of the energy harvested at a lower trophic level is transferred up to the next higher trophic level.

Biogeochemical Cycles

Cycles where nutrients and substances move continuously through ecosystems, spending time in living things, soil, the atmosphere, or bodies of water.

Biotic Factors

The living components within an ecosystem.

Abiotic Factors

The non-living components within an ecosystem.

Evaporation

The process where the Sun heats water from oceans, rivers, and inland sources, turning it into water vapor.

Transpiration

The process where water evaporates from the leaves of plants.

Condensation

The process where water vapor rises, cools, and forms liquid droplets that make up clouds.

Precipitation

The fall of water from the atmosphere in the form of rain, snow, hail, or sleet due to gravity.

Infiltration

The process by which some precipitation soaks into the soil and rock layers.

Photosynthesis

The food-making process in plants with the equation $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$.

Cellular Respiration

The chemical process of breaking down glucose in living things to produce energy, following the equation $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy}$.

Fossil Fuels

Remnants of ancient swamps and forests, such as coal, oil, and natural gas, that store carbon for millions of years.

Combustion

The process of burning fossil fuels for energy, which releases stored $CO_2$ into the atmosphere.

Nitrogen Gas ($N_2$)

The form of nitrogen that makes up about $78\%$ of the air in the Earth's atmosphere.

Nitrogen Fixation

The conversion of atmospheric nitrogen into organic compounds by certain bacteria or through lightning discharge.

Ammonification

The process where bacteria or fungi convert nitrogen gas ($N_2$) into the ammonium ion ($NH_4$).

Nitrification

A two-step process where soil bacteria convert ammonium ions ($NH_4^+$) into nitrite ions ($NO_2^-$) and then into nitrate ions ($NO_3^-$).

Assimilation

The process by which plants and animals take up nitrogen and incorporate it into their tissues.

Denitrification

The breakdown of substances by bacteria that releases nitrogen gas ($N_2$) back into the atmosphere, completing the cycle.