1What are the three levels of biodiversity?
Genetic diversity, species diversity, ecosystem diversity
2What does higher biodiversity indicate?
Higher ecosystem and population health
3What is species richness?
The total number of different species found in an ecosystem
4What is species evenness?
A measure of how balanced individual organisms are among different species in an ecosystem
5Why is genetic diversity beneficial?
It allows populations to better respond to environmental stressors like drought, disease, or famine
6What is a bottleneck event?
An environmental disturbance that drastically reduces population size and genetic diversity
7What is inbreeding depression?
When closely related organisms mate, increasing harmful genetic mutations
8What is ecosystem resilience?
The ability of an ecosystem to return to original conditions after a disturbance
9What are the four types of ecosystem services?
Provisioning, regulating, supporting, cultural
10What are provisioning services?
Goods taken directly from ecosystems or made from natural resources
11What are regulating services?
Ecosystem processes that moderate natural conditions like climate, air, and water quality
12What are supporting services?
Natural processes that sustain ecosystems and allow them to support life
13What are cultural services?
Recreation, tourism, and scientific knowledge benefits from ecosystems
14What is the theory of island biogeography?
Study of ecological relationships and species richness on islands
15How does island size affect species richness?
Larger islands support more species due to greater diversity and resources
16How does island distance from mainland affect species richness?
Closer islands have more species due to easier migration
17What is adaptive radiation?
Rapid evolution of a species into several new species to use different resources
18What is ecological tolerance?
Range of abiotic conditions an organism can endure before injury or death
19What are the three zones of ecological tolerance?
Optimal range, zone of physiological stress, zone of intolerance
20What are limiting factors?
The abiotic factor most likely to regulate population growth
21What are natural disturbances?
Events like tornadoes, hurricanes, or fires that disrupt ecosystems
22What are the three types of disturbance frequency?
Periodic, episodic, random
23What is natural climate change?
Long-term shifts in Earth’s climate due to orbit, tilt, and glacial cycles
24How does environmental change affect habitats?
It can cause widespread habitat loss or force species migration
25What is adaptation?
A new trait that increases an organism’s fitness
26What is natural selection?
Process where better-adapted organisms survive and reproduce more
27What is selective pressure?
Environmental conditions that kill individuals without adaptations
28How does pace of evolution affect species survival?
Faster changes make adaptation harder, leading to migration or extinction
29What is primary succession?
Succession starting from bare rock with no soil
30What is secondary succession?
Succession starting with existing soil after a disturbance
31What are pioneer species?
Fast-growing, sun-tolerant species that colonize bare soil or rock
32What are mid-successional species?
Species that need deeper, more nutrient-rich soils than pioneers
33What are late successional species?
Large, slow-growing, shade-tolerant trees requiring deep soils
34What does high species richness indicate?
Many different species are present, suggesting abundant resources and ecosystem health
35What does high evenness indicate?
Species populations are balanced, with no single species dominating
36Why does genetic diversity help survival?
It increases the chance some individuals have traits that resist stressors like disease or drought
37Why do bottleneck events reduce future survival?
They leave fewer individuals with less genetic diversity, making populations more vulnerable later
38What’s the difference between provisioning and regulating services?
Provisioning gives physical goods (food, wood), regulating controls natural conditions (air, water, climate)
39Why is pollination sometimes considered regulating, sometimes supporting?
Different sources classify it differently, but College Board uses regulating since it maintains reproduction and biodiversity
40Why do humans disrupt ecosystem services?
Activities like deforestation and overfishing remove resources and reduce natural regulation
41Why do larger islands support more species?
They offer more habitats, niches, and food, supporting bigger, more resilient populations
42Why do closer islands have more species?
It’s easier for organisms to migrate, keeping populations larger and more diverse
43Why do species evolve uniquely on islands?
Limited resources and isolation increase pressure to adapt into new niches
44Why do individuals have slightly different tolerance ranges?
Genetic diversity allows some to withstand conditions outside the average range
45Why is global warming a threat to tolerance?
It pushes temperature, rainfall, and oxygen levels beyond species’ survival limits
46What’s the difference between periodic, episodic, and random events?
Periodic = regular (wet/dry seasons), episodic = irregular but occasional (hurricanes), random = unpredictable (volcanoes)
47Why do species migrate after disruptions?
To follow resources and climate that remain within their tolerance