All flashcards
Flashcard 1: Which statement best describes how a disturbance can change carrying capacity (K)?
Answer: It can reduce or increase available resources, changing K. Disturbances alter resource availability, which directly affects carrying capacity.
Flashcard 2: What is primary succession?
Answer: Succession starting where no soil exists. Begins on bare rock or lava where organisms must create soil from scratch.
Flashcard 3: What is a population bottleneck caused by a disturbance?
Answer: A sharp size reduction that lowers genetic variation. Few survivors have limited genetic diversity, affecting future generations.
Flashcard 4: Identify the best evidence that a disturbance increased food supply for herbivores.
Answer: Increased plant biomass or plant cover after the event. More plants mean more food available for animals that eat them.
Flashcard 5: What is the best definition of a disturbance in an ecosystem in population dynamics?
Answer: An event that changes resource availability and alters population size or growth. Disturbances disrupt ecosystems by changing resources that populations need.
Flashcard 6: What is population dynamics?
Answer: Changes in population size and composition over time. Tracks how populations grow, shrink, and change through births, deaths, and migration.
Flashcard 7: What is ecological succession as it relates to disturbances?
Answer: Predictable community change over time after a disturbance. Species replace each other in predictable patterns as ecosystems recover.
Flashcard 8: Identify the immediate population response most likely after a severe wildfire in a forest.
Answer: A rapid decrease in population size. Fire kills organisms and destroys habitat, causing immediate population decline.
Flashcard 9: Which graph pattern best indicates a sudden disturbance: gradual increase or abrupt drop in population size?
Answer: Abrupt drop in population size. Sudden disturbances cause immediate deaths, shown as sharp population drops.
Flashcard 10: Which evidence best shows a disturbance caused a population decline: lower births or higher immigration?
Answer: Lower births. Fewer births directly reduces population, while immigration adds individuals.
Flashcard 11: Which option is density-independent: drought or competition for food?
Answer: Drought. Weather events affect populations equally regardless of how crowded they are.
Flashcard 12: Which option is density-dependent: disease spread or a hurricane?
Answer: Disease spread. Diseases spread faster in crowded populations, making it density-dependent.
Flashcard 13: What is carrying capacity (K)?
Answer: The largest population an environment can support long term. Limited by resources like food, water, and space available in the environment.
Flashcard 14: Which disturbance most likely leads to secondary succession: volcanic lava flow or a forest fire?
Answer: A forest fire. Fire leaves soil intact, while lava creates bare rock requiring primary succession.
Flashcard 15: What is secondary succession?
Answer: Succession after a disturbance where soil remains. Recovery is faster because soil and seeds already exist in the area.
Flashcard 16: Which evidence most strongly supports that a disturbance reduced habitat: fewer nesting sites or more predators?
Answer: Fewer nesting sites. Lost nesting sites directly show habitat destruction, unlike predator changes.
Flashcard 17: What is population density?
Answer: Number of individuals per unit area or volume. Measures crowding, which affects competition and resource availability.
Flashcard 18: Which measurement is best evidence of a population increase after a disturbance: higher survival rate or lower emigration?
Answer: Higher survival rate. More individuals surviving directly increases population size.
Flashcard 19: A storm kills many trees. Which population change is most likely for a bird that nests in trees?
Answer: Decrease due to reduced nesting sites. Birds need trees for breeding and shelter.
Flashcard 20: A drought reduces plant biomass. Which change is most likely for an herbivore population?
Answer: Decrease due to reduced food availability. Herbivores depend directly on plants for food.
Flashcard 21: A new predator is introduced. Which evidence best shows it caused the prey decline?
Answer: Prey decline begins after predator arrival; predation marks increase. Temporal correlation and physical evidence link cause to effect.
Flashcard 22: A disease spreads faster as population density rises. What type of limiting factor is this?
Answer: Density-dependent limiting factor. Its impact increases with population density.
Flashcard 23: Choose the best claim supported by evidence: after a flood, insects increased and birds increased later.
Answer: Birds increased due to more insect prey after the flood. Flood created conditions favoring insects, which feed birds.
Flashcard 24: A disturbance reduces a rabbit population from 200 to 50. What is the percent decrease?
Answer: 75% decrease. Calculate: (200−50)/200imes100=75%.
Flashcard 25: Identify the best evidence that a disturbance lowered birth rate rather than increased death rate.
Answer: Fewer juveniles per adult with similar adult survival. Adults survived but reproduced less successfully.
Flashcard 26: What is a disturbance in an ecosystem, in the context of population dynamics?
Answer: An event that changes conditions and affects population size or growth. Disturbances disrupt ecosystem balance, causing population fluctuations.
Flashcard 27: Which evidence best indicates a population decline after a disturbance?
Answer: Lower population counts and reduced birth rate or higher death rate. Both metrics directly measure population decrease.
Flashcard 28: What is carrying capacity (K)?
Answer: Maximum population an environment can support long term. Limited by resources like food, water, and space.
Flashcard 29: Identify the density-dependent limiting factor most likely to increase after overcrowding.
Answer: Disease transmission. Close contact in crowded conditions spreads pathogens rapidly.
Flashcard 30: Identify the density-independent limiting factor in this list: drought, disease, competition.
Answer: Drought. Affects all individuals equally, regardless of population density.