🧬CYCLING OF MATTER SCIENCE QUIZ🧪

Comprehensive practice flashcards reviewing the carbon, nitrogen, water, and oxygen cycles, along with the greenhouse effect, decomposition, and matter vs. energy movement in ecosystems.

How does the movement of energy through an ecosystem differ from the movement of matter?

Energy gets distributed from the Sun and flows through different trophic levels, whereas matter cycles continuously through the ecosystem by being broken down by detritivores and recycled into soil nutrients.

What biological process removes carbon dioxide ($CO_2$) from the atmosphere, and how does it function in an ecosystem?

Photosynthesis; plants absorb atmospheric carbon dioxide and water in the presence of sunlight to produce glucose, utilizing carbon released by organisms during cellular respiration.

What process releases carbon dioxide back into the atmosphere when organisms break down food to produce usable energy ($ATP$)?

Cellular respiration.

What are the three forms in which carbon is stored underground as fossil fuels, and how do they form over long periods?

Coal, oil, and natural gas; they form over millions of years when dead organic matter is buried under accumulating heat and pressure.

How does decomposition contribute to the cycling of carbon, and where can the decomposed carbon go?

Decomposers break down dead organic matter and animal wastes to recycle nutrients; the released carbon can enter the atmosphere as $CO_2$ or be stored in the soil as organic matter.

How does the combustion of fossil fuels disrupt the natural balance of the carbon cycle?

Burning fossil fuels releases carbon dioxide into the atmosphere at a rate faster than plants and oceans can absorb it, increasing overall atmospheric $CO_2$ levels.

Why is nitrogen essential to living organisms, and what two major biological molecules require it?

Nitrogen is required to synthesize proteins (such as muscle tissue) and $DNA$ molecules, which carry genetic instructions.

Can plants and animals directly utilize nitrogen gas ($N_2$) from the atmosphere?

No; atmospheric nitrogen must first undergo nitrogen fixation to be converted into usable nitrogen compounds.

What two natural phenomena perform nitrogen fixation to convert atmospheric nitrogen into compounds plants can use?

Nitrogen-fixing bacteria (found in the soil and on plant roots) and lightning.

How do plants and animals each obtain nitrogen in an ecosystem?

Plants absorb usable nitrogen compounds from the soil through their root systems, while animals obtain nitrogen by consuming plants or other animals.

How do decomposers and agricultural practices return nitrogen to the soil?

Decomposers break down dead tissues and animal waste, releasing nitrogen back into the soil as nutrients; farmers also add nitrogen to fields by spreading animal waste, called manure.

What is evaporation, and what other two biological processes release water vapor into the atmosphere?

Evaporation is the process where liquid water turns into water vapor; water vapor is also released when plants release moisture through transpiration and when animals exhale.

What happens during condensation and precipitation in the water cycle?

Condensation occurs when rising water vapor cools and turns back into liquid water to form clouds; precipitation occurs when water falls from clouds as rain, snow, sleet, or hail.

What two distinct pathways can water take after falling to Earth's surface as precipitation?

Runoff (flowing across land into rivers, lakes, and oceans) and infiltration (soaking into the ground and soil).

Why is matter described as cycling through an ecosystem rather than flowing?

Matter cycles because its total amount is conserved and continually reused between the environment and living organisms, whereas energy flows in a one-way path and dissipates.

How do the water cycle and carbon cycle directly interact to support ecosystems?

Water helps transport carbon through the environment; for example, ocean water absorbs atmospheric $CO_2$ while continually evaporating and returning via precipitation.

What microscopic organisms are responsible for producing more than $50\%$ of the oxygen in Earth's atmosphere?

Phytoplankton (unicellular photosynthetic organisms living in water).

Why was the evolutionary emergence of photosynthetic bacteria critical for Earth's early atmosphere?

Earth's early atmosphere lacked oxygen gas; the evolution of photosynthetic bacteria introduced oxygen into the atmosphere, making aerobic respiration possible.

What is the greenhouse effect, and why is it essential for life on Earth?

It is the process by which greenhouse gases in Earth's atmosphere absorb thermal energy reflected from solar radiation, trapping heat and preventing the planet from becoming too cold.

What human activities increase greenhouse gases, and what steps help mitigate this impact?

Burning fossil fuels (coal, oil, and natural gas) for transportation, electricity, and home heating increases $CO_2$; impact can be reduced by using natural renewable resources like solar energy and cutting back on electricity and gas consumption.

In the classroom science probe regarding plant and animal respiration, what was Flynn's perspective on gas exchange?

Flynn stated that animals take in oxygen and breathe out carbon dioxide, while plants take in carbon dioxide and release oxygen in a continuous cycle.

In the phenomenon activity modeling carbon paths, how does coal move through human systems into the environment?

Coal is deposited underground over long geologic periods, extracted through mining, transported to factories and power plants, and combusted to release energy and carbon dioxide.