Parts of an Ecosystem
Define "ecosystem" using both living and nonliving parts.
100 — An ecosystem is all organisms living together in a particular place plus their nonliving environment.
100 — What resources do individual organisms need to grow, according to the documents?
100 — Food, water, shelter (living and nonliving resources).
100 — Give one example of an abundant resource from the student texts and the typical ecosystem where it’s abundant.
100 — Sunlight on the prairie; abundant sunlight supports plant growth.
Define "carrying capacity"
100 — Carrying capacity: maximum population size sustainably supported by available biotic and abiotic resources
200 — Give two examples of biotic factors from the uploaded content and explain why each is biotic.
200 — Examples: tadpoles (biotic — living organism), green algae (biotic — living organism).
200 — Explain how population growth depends on resource availability; give one example
200 — If resources are abundant, population may increase; example: rainy season increases plant food, deer population may grow.
200 — Explain what an algal bloom is and one human-caused process from the content that can lead to it.
200 — Algal bloom: extreme algal growth from abundant nutrients; caused by fertilizer runoff into aquatic systems
200 — Give two natural events listed in the materials that can temporarily limit resource availability and explain one effect on populations.
200 — Wildfires and droughts; e.g., drought reduces plant growth → herbivore populations decline.
300 — Name three abiotic factors listed in the content and explain how one of them can limit an organism's survival.
300 — Examples: air, sunlight, water. Sunlight can limit photosynthesis and thus organism survival.
300 — Define exponential growth as described in the materials and state one condition that can produce it.
300 — Repeatedly multiplying growth factor leads to exponential growth; occurs when resources remain plentiful.
300 — The periodical cicadas are given as an example of a temporary abundance. Explain how their mass emergence affects predator populations.
300 — Cicada emergence provides abundant food; predators (birds) increase feeding and may temporarily increase in energy or reproduction.
300 — Explain how limited abiotic resources (use dissolved oxygen in a lake example) can change the health and population size of fish.
300 — Low dissolved oxygen harms fish health, reduces reproduction, can cause population declines or fish kills.
400 — Explain why a decaying log is considered a biotic factor even though it is not living.
400 — A decaying log is remains of a living thing; it was produced by biological processes and can host organisms.
400 — Describe how an increase in population size can change resource availability per individual and one ecological consequence.
400 — More individuals → fewer resources per individual → increased competition, lower individual growth or reproduction, possible die-off.
400 — If nutrients for algae never ran out, the textbook asks what else might limit algal population growth — name two plausible limiting factors and justify each.
400 — Possible limits: space (physical area), predation, disease, or oxygen availability; even with nutrients, light or oxygen might limit growth.
400 -- Identify which forest layers receive the least and most light and explain one resource that is likely limited in the lowest layer.
400 — Least light: forest floor; most light: emergent layer. Light limited on forest floor; nutrients or space may be limited higher up.
500 — Describe how baby birds might interact with at least two biotic and two abiotic factors in their nest area.
500 — Sample: Biotic — parent birds feed chicks, other insects provide food; Abiotic — temperature affects chick survival, water availability for drinking/bathing.
500 — Using the Alligator Rivers example (egrets and storks), explain how competition for shared resources could change population growth rates for both bird species.
500 — If egrets and storks compete for fish, one species may decline if outcompeted; both could show reduced reproduction if fish declines.
500 — Using the flounder–crab relationship (Question 28), create a cause-and-effect statement describing how an abundance of crabs would affect flounder and one other population in the food web.
500 — Abundant crabs → flounder population may increase (more food). Other predators of crabs may also increase; but if crabs overgraze their own food, crab numbers later decline.
500 — Predict how an increase in hyena population would affect lion population. Then give a parallel example in a different ecosystem and predict the similar interaction.
500 — Increased hyenas → competition reduces lion food and may lower lion numbers. Parallel: increase in one rodent predator could reduce another mesopredator through competition, causing its decline.