AP Biology Exam Review: Ecology Flashcards

Flashcards based on Unit 8 Ecology, covering responses to the environment, energy flow, population ecology, community ecology, biodiversity, and disruptions to ecosystems.

How do organisms respond to environmental changes?

Behaviorally (changing location/position) and physiologically (homeostatic mechanisms like evaporative cooling).

What is Kinesis?

Undirected movement in response to a stimulus, including orthokinesis (speed) or klinokinesis (turning).

What is Taxis?

Directed movement towards or away from a stimulus, such as phototaxis (light), chemotaxis (chemicals), or geotaxis (gravity).

How does cooperative behavior increase evolutionary fitness?

Increases chances of survival and reproduction, leading to more fertile offspring and increased fitness.

What is the difference between ectotherms and endotherms?

Ectotherms rely on the external environment for temperature regulation, while endotherms regulate body temperature internally by producing heat.

What is the relationship between metabolic rate and organism size?

Larger organisms have a lower metabolic rate per unit body mass than smaller organisms.

When do organisms grow versus when do they die regarding energy?

Organisms grow when energy input exceeds output, and die when energy output exceeds input.

What are the trophic levels in a simplified food chain?

Producers → primary consumers → secondary consumers → tertiary consumers.

What happens to a food chain with increased sunlight?

Increased photosynthesis leads to increased energy available to producers, boosting the entire ecosystem.

What are the differences between autotrophs and heterotrophs?

Autotrophs produce sugars from sunlight or chemicals; heterotrophs eat autotrophs to obtain sugars.

Photosynthesis vs. chemosynthesis

Photosynthesis uses light energy to produce sugars, while chemosynthesis uses energy from chemical reactions.

How is population growth calculated?

(Births + immigration) / (deaths + emigration)

How is exponential growth calculated and when does it occur?

rmaxN, and it occurs when resources are unlimited.

Density dependent factors vs Density independent factors

Density dependent factors limit population size based on density (e.g., disease); density independent factors affect all populations equally (e.g., natural disaster).

When is logistic growth calculated and when will logistics growth occur?

Logistic growth occurs when a population is reaching its carrying capacity.

What is a community (in ecological context)?

An interacting group of various species in a common location.

How does the Simpson's Diversity Index work?

It measures diversity considering species number and relative abundance; diversity increases with species richness and evenness.

Describe the trophic cascade model.

Predators limit prey density/behavior, enhancing survival of the next lower trophic level; powerful indirect ecosystem interactions.

Describe the resource partitioning model.

Division of limited resources by species to avoid competition in an ecological niche, to coexist with one another.

Mutualism

+/+, an example is sea anemone and clownfish

Commensalism

+/0, an example is lichen on tree bark

Parasitism

+/-, an example is tapeworm in the gut of a deer

What is the relationship between diversity and resilience?

Diversity of responses contributes to resilience, which is how well an ecosystem responds after environmental change.

How do keystone species maintain biodiversity?

By influencing the abundance and type of other species in a habitat, essential for the local food web.

What happens when a keystone species is removed?

The entire ecosystem radically changes or ceases to exist.

How do adaptations and mutations affect the diversity of a system?

Mutations increase genetic diversity within a population/species. Adaptation diversity allows species to withstand ecosystem changes.

What happens to populations when they have unlimited resources?

They grow exponentially.

What are three ways humans negatively impact biodiversity?

Destruction, degradation, and fragmentation of habitats; reduction of individual survival; introduction of alien species.

How do invasive species spread and why is it harmful?

Capable of causing extinctions of native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats

How do meteorological or geological events impact biodiversity?

Decrease biodiversity (fire, flood, etc., reduces populations and subsequently reduces genetic diversity).