- Refer to the ecosystem model. Which path correctly traces matter moving between organisms and the environment and supports the idea that matter cycles through ecosystems?
Model: Shrub → Deer; Deer → Mountain lion; dead organisms/waste → Decomposers; decomposers → Soil nutrients; soil nutrients → Shrub; Shrub ↔ Air (matter taken in and released).
Answer: Soil nutrients → Shrub → Deer → Mountain lion → Dead/waste → Decomposers → Soil nutrients
Tracing matter in ecosystems involves tracking atoms and molecules as they move through organisms and between living and nonliving components. Matter moves through ecosystems in cycles, passing from the environment to producers to consumers and back to the environment through decomposition. Models show this cycling with arrows that create complete loops, demonstrating that matter is reused rather than lost. To verify a complete cycle, start at any point and follow arrows to see if you can return to the starting point. A common misconception is that matter disappears or turns into energy, but matter is conserved and only changes form. Option A correctly traces a complete cycle from soil nutrients through organisms and decomposers back to soil nutrients. This cycling of matter explains how ecosystems can function continuously without depleting resources.
- Ecosystem model (described): In a stream ecosystem, water plants (living) take in matter from stream water (nonliving) and air (nonliving). Mayfly larvae (living) eat water plants. Trout (living) eat mayfly larvae. Decomposers (living) take in dead matter and release matter that becomes part of streambed sediment (nonliving). Arrows are labeled with the matter moving. The model states: Matter cycles through ecosystems.
Which statement about matter movement is supported by evidence from the model?
Answer: Matter can move from nonliving parts (water and air) into living plants, shown by labeled arrows into water plants
The core skill in tracing matter in ecosystems is using model evidence to support statements about matter movement. Matter moves through ecosystems from nonliving components like water and air into living ones, then cycles back. Models illustrate this with labeled arrows showing inflows to plants and returns via decomposers. A checking strategy is to match statements directly to arrow labels and directions. One misconception is that matter flows unidirectionally without returning, but models show cycles. Tracing matter elucidates how ecosystems reuse resources. Broadly, this process explains the interconnected functioning of ecosystem parts.
- Ecosystem model (described): In a grassland, grass (living) takes in matter from soil (nonliving) and air (nonliving). A mouse (living) eats grass seeds and leaves. A snake (living) eats mice. A hawk (living) eats snakes. Decomposers (living) break down dead matter from grass, mice, snakes, and hawks. Matter from decomposers becomes part of the soil. Arrows are labeled with the matter moving along each arrow. The model states: Matter cycles through ecosystems.
What evidence from the ecosystem model best shows that matter cycles (moves and can return) through the ecosystem?
Answer: There are arrows showing matter moving from decomposers to soil and from soil to grass, linking living and nonliving parts
The core skill in tracing matter in ecosystems is identifying evidence that demonstrates matter's cyclic movement. Matter moves through ecosystems from nonliving sources to producers, consumers, and back through decomposers to the environment. Models show cycling with interconnected arrows, like from soil to grass and decomposers back to soil, illustrating return paths. A checking strategy is to look for arrows linking living and nonliving parts to confirm cycling. People often misconceive that matter stops at top predators, but it continues via decomposition. Tracing matter helps explain nutrient availability for ongoing growth. In general, this cycling underpins ecosystem stability and functioning.
- Which step in a plant model best shows water returning to nonliving parts?
Answer: Leaf releases water to air
Water returns to the nonliving environment when leaves release it into the air as vapor, since air is nonliving. The root absorbing water moves water into the living plant instead of returning it. The leaf using water to make sugar keeps water in the living system, so transpiration is the best answer.
- Refer to the ecosystem model: CO2 in air → grass → grasshopper → frog → snake; dead organisms/waste → decomposers → nutrients in soil → grass; decomposers → CO2 in air. The arrows represent matter movement, and the labels clarify which matter is moving. This is evidence that matter cycles through ecosystems.
Which statement about matter movement is supported by the model?
Answer: Matter can move from organisms to the environment and later move back into organisms.
The core skill is tracing matter in ecosystems to see how it supports life cycles. Matter moves through ecosystems from the environment into organisms and back, ensuring continuous availability. Models demonstrate cycling with labeled arrows showing transfers like nutrients from soil to plants and CO2 returning to air via decomposers. A checking strategy is to verify if the model shows matter returning to nonliving parts, confirming a cycle. One misconception is that matter flows only one way and gets used up, but it actually recirculates. Tracing matter helps explain nutrient reuse in food webs. Ultimately, it illustrates how ecosystems maintain balance and function sustainably.
- A student looks at this labeled ecosystem model of matter movement: CO2 in air → grass; grass matter → cow; cow waste/dead matter → decomposers → nutrients in soil → grass; decomposers → CO2 in air. The model is evidence that matter cycles through ecosystems.
Which claim is unsupported by the model?
Answer: Matter moves upward in the food chain because animals pull it up with their muscles.
Tracing matter in ecosystems identifies supported versus unsupported claims from models. Matter moves through ecosystems via living and nonliving components in defined cycles. Models show this with arrows linking air, soil, plants, animals, and decomposers accurately. Check by matching claims to arrow directions, rejecting those without evidence. A misconception is that matter moves upward due to animal actions, but it's driven by consumption and decomposition. Tracing matter validates true ecosystem processes. It explains how models reveal functional dynamics without myths.
- Use the ecosystem model: CO2 in air → algae → small fish → big fish → heron; dead organisms/waste → decomposers → nutrients in water → algae; decomposers → CO2 in air. Arrows show matter movement and the labels identify the matter. This model is evidence that matter cycles through ecosystems.
Which prediction about matter movement is supported if the decomposers decrease a lot (fewer decomposers)?
Answer: Less matter from dead organisms will be returned to nutrients in the water, so less matter will move from water nutrients into algae.
The core skill involves tracing matter to predict changes in ecosystems, like population shifts. Matter moves through ecosystems in cycles, from nonliving stores to organisms and back through processes like decomposition. Models show cycling with arrows linking components, such as dead matter to decomposers to water nutrients. A strategy to check is simulating changes, like fewer decomposers, and tracing impacts on matter flow. Misconception: matter turns into energy when broken down, but it remains as matter in different forms. Tracing matter shows how disruptions affect availability. This understanding explains ecosystem resilience and functioning under stress.
- Refer to the ecosystem model and use evidence from the arrows and labels to trace matter. Which statement about matter movement is supported and shows matter cycling through the ecosystem?
Answer: Matter can move from the nonliving environment into plants, then into animals, and later back to the nonliving environment.
This question requires using model evidence to trace matter movement and identify cycling. Matter moves through ecosystems by transferring between organisms when they eat, produce waste, or die, and between organisms and their environment. Models show this cycling through arrows labeled with matter types, demonstrating complete pathways from environment to organisms and back. To verify cycling, check that the statement describes matter returning to a reusable form in the environment. A misconception is that matter flow is one-directional, but ecosystem models clearly show matter returning to the nonliving environment through decomposition. Understanding matter cycling explains how ecosystems maintain nutrient availability despite continuous organism growth and death.
- The ecosystem model shows labeled arrows for matter movement: CO2 in air → desert plant; desert plant matter → insect → lizard → hawk; dead organisms/waste → decomposers → nutrients in soil → desert plant; decomposers → CO2 in air. The model shows matter cycling through ecosystems.
Which path shows matter moving from a living organism to the nonliving environment and then back into a living organism?
Answer: Hawk → decomposers → nutrients in soil → desert plant
The core skill is tracing matter paths that connect living to nonliving and back in ecosystems. Matter moves through ecosystems from organisms to environment via decomposition, then re-enters life. Models depict this with arrows from dead matter to soil or air, then to plants. A checking strategy is to identify paths crossing living-nonliving boundaries and returning. Misconception: matter stops at top predators, but it cycles back through death and decay. Tracing matter shows full loops sustaining biodiversity. This explains ecosystem functioning through continuous matter transformation and reuse.
- Use the ecosystem model to trace matter. Which statement provides evidence that matter moves between organisms and the environment and therefore cycles through the ecosystem?
Answer: The model shows matter moving from soil into plants and later moving from decomposers back into soil.
This question requires identifying evidence of matter cycling between organisms and environment. Matter moves through ecosystems by transferring between living things and their nonliving surroundings in continuous cycles. Models show this cycling through arrows that trace matter from soil to plants and from decomposers back to soil, completing the cycle. To find evidence of cycling, look for arrows showing matter both entering organisms from the environment and returning to it. A misconception is that models only show single moments or that matter stops at top predators, but models represent ongoing processes where matter continuously cycles. Understanding these complete cycles explains how ecosystems maintain the nutrients needed to support life indefinitely.
- Refer to the ecosystem model. What evidence in the model shows that matter cycles through ecosystems (moves between organisms and the environment and can return to organisms)?
Model: Algae → Snail → Fish; dead organisms/waste → Decomposers; decomposers → Water nutrients; water nutrients → Algae; Fish → Water (waste matter).
Answer: Arrows show that matter can move from organisms to decomposers, into water nutrients, and back into algae.
Tracing matter in ecosystems involves following the movement of atoms and molecules through different organisms and environmental components. Matter moves through ecosystems in continuous cycles, passing from producers to consumers to decomposers and back to the environment. Models show this cycling using arrows that indicate how matter flows between living and nonliving parts of the ecosystem. To find evidence of cycling, look for pathways where matter returns to organisms after passing through the environment. A common misconception is that matter stops moving or disappears, but it actually continues cycling. Option B correctly identifies the complete cycle: algae to snail to fish to decomposers to water nutrients and back to algae. This cycling of matter explains how aquatic ecosystems can sustain life indefinitely.
- Refer to the ecosystem model. Which statement about matter movement is supported by evidence in the model and shows that matter cycles through ecosystems?
Model: Plant → Grasshopper → Frog; dead organisms/waste → Decomposers; decomposers → Soil nutrients; soil nutrients → Plant; Plant ↔ Air (matter taken in and released).
Answer: Matter from dead organisms and waste can become soil nutrients that plants take in, helping matter move from organisms to the environment and back to organisms.
Tracing matter in ecosystems involves following atoms and molecules as they move between organisms and the environment. Matter moves through ecosystems by cycling between living things and nonliving components like air, water, and soil. Models show this cycling using arrows that indicate the direction of matter movement from one component to another. To verify matter cycling, look for pathways where matter returns to its starting point through decomposition and nutrient uptake. A common misconception is that matter only moves in one direction, but it actually cycles continuously. Option C correctly identifies that decomposers break down dead matter into soil nutrients that plants can absorb, completing the cycle. This cycling of matter explains how ecosystems can continue functioning without running out of essential materials.
- Use the ecosystem model to trace matter and evaluate a claim. Which claim about matter is incorrect based on the evidence in the model?
Model: Tree → Caterpillar → Bird; dead organisms/waste → Decomposers; decomposers → Soil nutrients; soil nutrients → Tree; Tree ↔ Air (matter taken in and released). Statement included: Matter cycles through ecosystems.
Answer: Matter is created when decomposers break down dead organisms, so there is more matter in the ecosystem after decomposition.
Tracing matter in ecosystems means tracking atoms and molecules as they move through food webs and environmental components. Matter moves through ecosystems by passing from one organism to another and cycling between living and nonliving parts. Models show this cycling with arrows connecting producers, consumers, decomposers, and environmental components like soil and air. To identify incorrect claims, check if they violate the law of conservation of matter, which states matter cannot be created or destroyed. The misconception in option C is that decomposers create new matter, when they actually just break down existing matter into simpler forms. Options A, B, and D correctly describe matter movement and cycling shown in the model. Understanding that matter is conserved helps explain how ecosystems maintain balance over long periods.
- Ecosystem model (described): Grass (living) is eaten by a rabbit (living). A hawk (living) eats the rabbit. When plants and animals die, decomposers in the soil (living) break down dead matter. Matter from decomposers becomes part of the soil (nonliving). Grass takes in matter from the soil and also takes in matter from the air (nonliving). Arrows in the model are labeled:
- soil matter → grass
- air matter → grass
- grass matter → rabbit
- rabbit matter → hawk
- dead matter → decomposers
- decomposer matter → soil
The model states: Matter cycles through ecosystems.
Which path shows matter moving through both living and nonliving parts of the ecosystem model?
Answer: Soil matter → grass → rabbit → hawk → dead matter → decomposers → soil
The core skill in tracing matter in ecosystems involves identifying how atoms and molecules transfer between living organisms and nonliving components. Matter moves through ecosystems in a continuous cycle, passing from nonliving sources like soil and air into producers, then to consumers, and back through decomposers. Models show this cycling with labeled arrows that indicate the direction and type of matter flow, such as from soil to plants and from dead matter to soil. To check understanding, trace a complete path in the model to ensure it includes both living and nonliving parts without matter disappearing. A common misconception is that matter vanishes after being used for energy, but actually, it is conserved and recycled. Tracing matter reveals how nutrients are reused, sustaining life in the ecosystem. Overall, this process explains why ecosystems can function indefinitely without losing matter.
- Ecosystem model (described): A forest ecosystem model shows: tree (living) → caterpillar (living) → bird (living). Dead leaves and dead animals become dead matter (nonliving). Decomposers (living) take in dead matter. Matter from decomposers becomes part of the soil (nonliving). The tree takes in matter from the soil and from the air (nonliving). Arrows are labeled with the type of matter moving (tree matter, caterpillar matter, bird matter, dead matter, decomposer matter, soil matter, air matter). The model states: Matter cycles through ecosystems.
A student makes four claims about the model. Which claim about matter is incorrect?
Answer: Once matter moves into the bird, it turns into energy, so that matter no longer exists in the ecosystem
The core skill in tracing matter in ecosystems is evaluating claims about matter movement using model evidence. Matter moves through ecosystems from nonliving elements like soil and air into living organisms and back via decomposition. Models depict cycling through arrows showing paths like from dead matter to decomposers and soil, emphasizing return flows. To check, compare each claim to the model's labeled arrows and identify any contradiction with cycling. A misconception is that matter converts to energy and disappears, but matter remains in different forms. Tracing matter clarifies how ecosystems recycle resources efficiently. Ultimately, this explains the sustained functioning of ecosystems over time.
- Ecosystem model (described): In a pond ecosystem, algae (living) take in matter from pond water (nonliving) and from the air (nonliving). A snail (living) eats algae. A fish (living) eats snails. When organisms die, bacteria and fungi (living decomposers) break down dead matter. Matter from decomposers becomes part of the pond mud (nonliving). Arrows are labeled:
- water matter → algae
- air matter → algae
- algae matter → snail
- snail matter → fish
- dead matter → decomposers
- decomposer matter → pond mud
The model states: Matter cycles through ecosystems.
Which statement about matter movement is supported by evidence from the ecosystem model?
Answer: Matter from dead organisms can move into decomposers and then become part of a nonliving part of the ecosystem (pond mud)
The core skill in tracing matter in ecosystems is analyzing models to find evidence of how matter flows between components. Matter moves through ecosystems by entering from nonliving parts like water and air into producers, then to consumers and decomposers, eventually returning to the environment. Models illustrate cycling with arrows labeled to show matter transferring, such as from dead organisms to decomposers and then to pond mud. A useful checking strategy is to evaluate each statement against the arrow directions and labels in the model for support. One misconception is that matter is created anew by growing organisms, but matter is conserved and only rearranged. By tracing matter, we understand how ecosystems maintain balance through recycling. This generalization highlights that ecosystem functioning depends on matter's perpetual circulation.
- Ecosystem model (described): Two ecosystems are modeled.
Model 1 (garden): soil matter → tomato plant; air matter → tomato plant; tomato plant matter → caterpillar; caterpillar matter → bird; dead matter → decomposers; decomposer matter → soil.
Model 2 (ocean shore): water matter → seaweed; air matter → seaweed; seaweed matter → crab; crab matter → gull; dead matter → decomposers; decomposer matter → sand/sediment.
Both models state: Matter cycles through ecosystems.
Comparison: Which statement is supported by evidence from both models?
Answer: Matter moves from producers to consumers and can also move from decomposers into a nonliving part of the environment
The core skill in tracing matter in ecosystems is comparing models to find common patterns in matter movement. Matter moves through ecosystems from producers to consumers and decomposers, returning to nonliving parts like soil or sediment. Models demonstrate cycling with similar arrow structures across ecosystems, showing universal patterns. A checking strategy is to list shared arrow paths in both models for consistency. People misconceive that matter stays only in living things, but it cycles to nonliving. Tracing matter across models reveals shared recycling mechanisms. In essence, this explains how diverse ecosystems function similarly.
- Refer to the ecosystem model: CO2 in air → corn plant; corn plant matter → mouse → owl; dead organisms/waste → decomposers → nutrients in soil → corn plant; decomposers → CO2 in air. The arrows represent matter movement and labels name the matter. This model shows matter cycling through ecosystems.
Which path best traces matter that starts as nutrients in soil and later becomes part of an owl?
Answer: Nutrients in soil → corn plant → mouse → owl
The core skill is tracing specific matter paths from sources like soil nutrients through ecosystems. Matter moves through ecosystems starting from nonliving sources into producers, then consumers, in a cycle. Models show this with arrows tracing sequences, such as soil to plants to animals. A checking strategy is to follow one type of matter end-to-end without detours like to sunlight. Misconception: matter stays permanently in one organism, but it transfers via consumption. Tracing matter demonstrates resource sharing among species. It explains ecosystem functioning through interconnected food chains and nutrient return.
- Two ecosystem models both show labeled arrows for matter movement and state that matter cycles through ecosystems.
Model 1 (forest): CO2 in air → tree → beetle → bird; dead organisms/waste → decomposers → nutrients in soil → tree; decomposers → CO2 in air.
Model 2 (pond): CO2 in air → algae → insect larva → fish; dead organisms/waste → decomposers → nutrients in water → algae; decomposers → CO2 in air.
Which comparison about matter movement is supported by evidence from both models?
Answer: Both models show matter moving from dead organisms to decomposers and then into a nonliving store (soil or water nutrients).
Tracing matter helps compare models across ecosystems to find common cycling patterns. Matter moves through ecosystems similarly in different settings, from air to organisms and back. Models show cycling with consistent arrows for dead matter to decomposers to nonliving stores. Check by identifying shared features like matter return to soil or water in both models. A misconception is that cycling is unique to one ecosystem, but patterns are universal. Tracing matter highlights similarities in resource flow. This explains how diverse ecosystems function on the same principles of matter conservation.
- In a forest model, a fungus decays a fallen log. Which path best traces carbon?
Answer: log → fungus → air and soil
A fungus is a decomposer that takes in carbon directly from the fallen log. As it breaks down the log, carbon moves into the fungus and is released as carbon dioxide into the air and as organic matter into the soil. The tempting wrong path puts soil before fungus, but the fungus must consume the log before carbon can enter the soil.
