All flashcards
Flashcard 1: What does the term "limiting factor" mean in a population data set?
Answer: A resource or condition that restricts population growth. Examples include food, water, space, or predators that control population size.
Flashcard 2: What is the definition of carrying capacity (K) in an ecosystem?
Answer: The maximum population an environment can sustainably support. Determined by available resources and environmental conditions.
Flashcard 3: What is the difference between density-dependent and density-independent factors?
Answer: Density-dependent varies with density; density-independent does not. Competition and disease are density-dependent; weather is density-independent.
Flashcard 4: Which option is a density-independent population limiter: drought, disease, or competition?
Answer: Drought. Weather events affect populations regardless of their density.
Flashcard 5: What is a trophic cascade in population data after a predator is removed?
Answer: A chain of population changes across multiple trophic levels. Removing top predators causes ripple effects through food webs.
Flashcard 6: What does a population boom followed by a crash most strongly suggest about resources?
Answer: Resources were exceeded, then scarcity caused a decline. Overshoot occurs when populations exceed carrying capacity temporarily.
Flashcard 7: Which relationship is shown when two species both decrease as they use the same resource?
Answer: Competition. Both species need the same limited resource to survive.
Flashcard 8: Which relationship is shown when predator numbers rise shortly after prey numbers rise?
Answer: Predator-prey relationship with a time lag. Predators need time to reproduce in response to prey abundance.
Flashcard 9: Identify the dependent variable when a graph shows rabbit population versus time.
Answer: Rabbit population. The dependent variable (y-axis) changes in response to time.
Flashcard 10: Identify the independent variable when a graph shows algae population versus nitrate level.
Answer: Nitrate level. The independent variable (x-axis) is manipulated to observe effects.
Flashcard 11: Which option best describes this trend: prey rises first, then predator rises, then prey falls?
Answer: Predator increase caused prey decline after a time lag. Classic predator-prey cycle showing population oscillations.
Flashcard 12: A fish kill occurs after dissolved oxygen drops from 8 to 2 mg/L. What change most likely caused it?
Answer: Reduced oxygen availability limited fish survival. Fish require >4 mg/L dissolved oxygen to survive.
Flashcard 13: A lake’s phosphorus increases and algae rises sharply; underwater plants decline. What process is shown?
Answer: Eutrophication. Excess nutrients cause algae blooms that block light to plants.
Flashcard 14: A pollutant reduces insect population; bird population falls two months later. What is the likely link?
Answer: Food shortage caused the bird decline. Birds depend on insects as their primary food source.
Flashcard 15: After wolves are reintroduced, deer decrease and young trees increase. What interaction explains this?
Answer: Predation reduced herbivory, allowing plant recovery. Wolves control deer numbers, reducing browsing pressure on trees.
Flashcard 16: Choose the best claim: If average temperature rises, a cold-adapted species’ range shifts toward what direction?
Answer: Toward cooler areas (higher latitude or higher elevation). Species track their optimal temperature zones as climate changes.
Flashcard 17: Identify the most supported conclusion when a population stabilizes near a horizontal line labeled K.
Answer: The population reached carrying capacity (K). Growth stops when resources become limiting at carrying capacity.
Flashcard 18: What is the term for a relationship in which both species benefit (+/+)?
Answer: Mutualism. Both organisms gain advantages from their interaction, like bees and flowers.
Flashcard 19: What is the term for a relationship in which one benefits and the other is unaffected (+/0)?
Answer: Commensalism. One organism benefits while the other experiences no harm or help.
Flashcard 20: What is the term for a relationship in which both species are harmed (−/−) due to shared needs?
Answer: Competition. Both organisms suffer when competing for the same limited resources.
Flashcard 21: What is the term for a nonliving environmental factor such as temperature, rainfall, or pH?
Answer: Abiotic factor. Non-living components that influence living organisms in an ecosystem.
Flashcard 22: What is the term for a living environmental factor such as predators, prey, or disease organisms?
Answer: Biotic factor. Living components that interact with and affect other organisms.
Flashcard 23: What is the term for a limiting factor whose impact increases as population density increases?
Answer: Density-dependent limiting factor. Effects intensify in crowded populations, like disease spread or competition.
Flashcard 24: What is the term for a limiting factor that affects populations regardless of density?
Answer: Density-independent limiting factor. Affects all individuals equally, like natural disasters or climate events.
Flashcard 25: What is the term for the movement of individuals into a population, increasing its size?
Answer: Immigration. New individuals join from outside, adding to population numbers.
Flashcard 26: What is the term for the movement of individuals out of a population, decreasing its size?
Answer: Emigration. Individuals leave for other areas, reducing population numbers.
Flashcard 27: Which population change is most likely after a sudden drought reduces plant biomass in a grassland?
Answer: Herbivore populations decrease. Less plant food available means fewer herbivores can survive.
Flashcard 28: Which population change is most likely after wolves are removed from an ecosystem with deer and plants?
Answer: Deer population increases. Without predators controlling them, prey populations grow rapidly.
Flashcard 29: Which population change is most likely after an invasive predator is introduced to an island ecosystem?
Answer: Native prey populations decrease. New predators consume native prey that lack defenses against them.
Flashcard 30: Identify the likely effect on algae if fertilizer runoff increases nutrient levels in a lake.
Answer: Algae population increases (algal bloom). Extra nutrients cause rapid algae growth, depleting oxygen for other life.