Ecosystems & Watersheds
What is the term for living parts of an ecosystem (examples: plants, fish, birds)?
Biotic factors (living or once-living organisms: plants, fish, bacteria, macroinvertebrates, wildlife, migratory birds).
What property describes water's ability to stick to other surfaces (not to itself)?
Adhesion.
What subatomic particle determines the identity of an element?
Protons.
In an experiment, which variable is deliberately changed by the scientist?
Independent variable (IV)
What small animals without backbones are used as biological indicators of water health?
Macroinvertebrates (e.g., insect larvae, snails, worms).
What do you call the land area that drains water to a common outlet like a stream or bay?
Watershed (land area that water flows across or through on its way to a stream, lake, wetland, or other body of water).
What is cohesion and what observable effect does it cause at the water surface?
Cohesion is attraction between water molecules; it produces surface tension allowing insects to walk on water or water droplets to form beads.
What is a compound?
A compound is a substance formed when two or more different elements chemically bond. Water = H2O.
Which variable responds to the change and is measured?
Dependent variable (DV)
What does turbidity measure about water?
Turbidity measures water clarity (cloudiness due to suspended sediments).
Name two abiotic factors that affect which organisms can live in an area.
Examples: water supply, topography (elevation/slopes), landforms, geology, soils, sunlight, air quality/availability.
Why does water moderate coastal climates (name the related property of water)?
Because of water's high specific heat capacity it absorbs/releases heat slowly, moderating temperature changes near large bodies of water.
State the Law of Conservation of Matter in one sentence.
Matter is neither created nor destroyed; atoms are rearranged during physical and chemical changes.
Give three examples of constants you might keep the same when testing how fertilizer affects aquatic plant growth
Examples: light exposure, water temperature, container size/shape, water volume, salinity, type of plant, duration of experiment
Name two water quality functions of wetlands.
Wetlands regulate runoff/store floodwaters, reduce erosion, filter sediments/trap nutrients, break down pollutants, recharge groundwater, provide food/shelter/nurseries for wildlife.
What is a ridgeline or divide and how does it affect neighboring watersheds?
A ridgeline/divide is a high-elevation area that separates neighboring watersheds so water flows into different drainage systems.
List the three common natural states of water and give one example of where each is naturally found.
Solid (ice — glaciers/ice caps), liquid (lakes/oceans/rivers), gas (water vapor in the atmosphere).
In a chemical equation, what are reactants and what are products?
Reactants are starting substances; products are new substances formed after a chemical reaction.
Write a testable hypothesis for: "Does increased turbidity (cloudiness) lower dissolved oxygen levels?"
Example hypothesis: "If turbidity increases, then dissolved oxygen will decrease because suspended particles reduce light and photosynthesis."
What is an estuary and why is it important as a habitat for young marine species?
An estuary is a semi-enclosed area where freshwater mixes with ocean saltwater (tides drive mixing); estuaries are productive nurseries providing food and shelter for juvenile marine species.
Explain why water quality directly affects overall ecosystem health (give two reasons).
Water quality affects oxygen availability, pollutant levels, and habitat suitability — poor water quality can reduce biodiversity and disrupt food webs.
Explain how high specific heat capacity of water helps protect organisms during temperature swings.
High specific heat means water buffers temperature changes, helping aquatic organisms avoid rapid, stressful temperature swings.
How do electrons participate in forming chemical bonds when atoms make a compound?
Electrons are shared or transferred between atoms to form covalent or ionic bonds, creating compounds.
Describe the steps you would use to test the hypothesis you wrote for the turbidity and dissolved oxygen question (include IV, DV, constants, and one data collection method).
Steps: Ask question → Hypothesis (as above) → Experiment: IV = turbidity levels (low, medium, high); DV = dissolved oxygen concentration measured with a DO probe; Constants = water volume, temperature, plant type (if present), container size, salinity; Procedure = prepare water samples with measured amounts of sediment to create turbidity levels, measure DO at set intervals, record data, analyze with graphing, conclude.
List four chemical or physical parameters scientists measure to monitor water quality and briefly say what each measures.
Examples: pH (measures acidity/basicity), Temperature (measures warmth/cold affecting oxygen levels), Salinity (measures dissolved salts), Dissolved Oxygen (measures free oxygen available for aquatic organisms), Turbidity (measures clarity/suspended sediments), Biological indicators like macroinvertebrate diversity (indicates overall health).