Ecology Final

True or False?: In secondary succession, newly exposed or newly formed land is colonized by living things

False

True or false?: Herbivory is the consumption of plants by insects and other animals, is another interspecific relationship that affects populations.

True

A ______ consists all individuals of a species living within a specific area

Population

True or false?: An accelerating pattern of increasing population size is called exponential growth.

True

_________ occurs when two or more species evolve together, each adapting to changes in the other. 

Coevolution

 A ________ is a community of living organisms and their interactions with their abiotic (non-living; such as temperature, precipitation, soil, etc.) environment

Ecosystem

True or false?: Ecological efficiency (also called food chain efficiency) is the percentage of net production from one trophic level compared to the next lower trophic level.

True

Energy is acquired by living things in which of the following ways?

Photosynthesis, consumption, digestion

True or false?: Because geology and chemistry have major roles in the study of this process, the recycling of inorganic matter and nutrients between living organisms and their environment (among atmosphere, oceans and lands) is called a biogeochemical cycle.

True

Many studies indicate that current CO₂ levels in our atmosphere fluctuate greatly, but are currently __________ higher than the maximum concentration during the past 400,000 years.

41%

True or false?: Biodiversity is a general term for the variety of life present in the biosphere.

True

When did the Pleistocene extinction occur?

10-12k years ago

True or false?: Overharvesting is a serious threat to many species, but particularly to aquatic species.

True

True or false?: Behavior refers to a change in activity of an organism in response to a stimulus.

True

Intrasexual selection occurs when individuals of one sex choose mates of the other sex based on a variety of visual, audio, tactile, or chemical cues.

False

Ch 13: Population Size & Density Measurement -

Quadrats (for immobile organisms) and Mark-Recapture Method: N = (s * n) / x, where N is total population, s is initial marked group, n is second sample size, and x is marked recaptures.

Ch 13: Population Dispersion Patterns -

Clumped (most common; resource-driven/social),

Uniform (territoriality/competition),

Random (independent of other individuals).

Ch 13: Life Tables & Mortality Rate -

Tables tracking cohort survival/reproduction. Mortality Rate = (number of individuals dying during interval) / (number of individuals surviving at beginning of interval).

Ch 13: Survivorship Curves -

Type I: High survival early/mid-life, steep mortality in old age (e.g., humans/large mammals).

Type II: Constant mortality rate across lifespan (e.g., birds).

Type III: High mortality early in life, few survive to old age (e.g., trees, marine invertebrates).

Ch 13: Life History Trade-Offs -

Organisms have limited energy/resources, creating trade-offs between fecundity (number of offspring) and parental investment/survival.

Ch 13: r-selected vs. K-selected Species -

r-selected: Adapt to unstable environments, high fecundity, small body size, early maturity, low parental investment (Type III curve).

K-selected: Adapt to stable environments near carrying capacity (K), low fecundity, large body size, late maturity, high parental care (Type I curve).

Ch 13: Population Growth Models -

Exponential Growth: dN/dt = rN (J-shaped curve, unlimited resources).

Logistic Growth: dN/dt = rN((K - N)/K) (S-shaped curve, carrying capacity K limits growth).

Ch 13: Density-Dependent vs. Density-Independent Factors -

Density-Dependent: Biotic factors whose impact varies with population size (e.g., competition, predation, disease, waste accumulation).

Density-Independent: Abiotic factors affecting populations regardless of density (e.g., weather, natural disasters, fires).

Ch 13: Human Population Growth & Overgrowth -

Humans experienced exponential growth due to agriculture, technology, and medicine; carrying capacity (K) is uncertain. Overgrowth consequences include resource depletion, habitat destruction, pollution, and biodiversity loss.

Ch 14: Predator-Prey Dynamics Graph -

Characterized by out-of-phase oscillations where prey population peaks first, followed by a peak in predator population, which then suppresses prey numbers.

Ch 14: Mechanical vs. Behavioral Defenses -

Mechanical: Physical structures deterring predators (e.g., porcupine quills, plant thorns).

Behavioral: Actions taken to avoid predation (e.g., schooling/flocking, alarming calls, feigning death).

Ch 14: Batesian vs. Müllerian Mimicry -

Batesian: A harmless species mimics a harmful/toxic species for protection.

Müllerian: Multiple harmful/toxic species share a similar warning coloration.

Ch 14: Competitive Exclusion Principle -

Two species competing for the exact same limiting resource cannot coexist indefinitely in the same niche.

Ch 14: Resource Partitioning & Character Displacement -

Resource Partitioning: Evolutionary division of niches (e.g., different perch heights in Anolis lizards).

Character Displacement: Divergence of physical traits in sympatric populations to minimize competition (e.g., Darwin's finch beak sizes).

Ch 14: Symbiotic Relationships -

Commensalism (+/0): One benefits, other unaffected (e.g., barnacles on whales).

Mutualism (+/+): Both species benefit (e.g., mycorrhizae and plant roots).

Parasitism (+/-): One benefits at expense of host (e.g., tapeworms in mammals).

Ch 14: Foundation vs. Keystone Species -

Foundation Species: Provide primary habitat structure and high biomass (e.g., kelp in kelp forests, corals).

Keystone Species: Disproportionately large impact on ecosystem relative to their abundance (e.g., sea otters, wolves).

Ch 14: Invasive Species & Examples -

Non-native species causing economic/ecological harm by lacking natural predators. Invasive Plants: Kudzu, Purple Loosestrife. Invasive Animals: Zebra Mussels, Cane Toads.

Ch 14: Primary vs. Secondary Succession -

Primary Succession: Occurs on brand new land devoid of soil (e.g., lava flow, retreating glacier); pioneer species are lichens/mosses.

Secondary Succession: Occurs after disturbance leaves soil intact (e.g., abandoned farm field, forest fire); recovers faster.

Ch 15: Ecosystem Structure & Food Webs -

Ecosystems include terrestrial, freshwater, and marine biomes.

Food Chains: Linear paths of energy transfer.

Food Webs: Interconnected network showing complex trophic relationships.

Trophic Levels: Primary Producers -> Primary Consumers -> Secondary Consumers -> Tertiary Consumers.

Ch 15: Primary Productivity Concepts -

Gross Primary Productivity (GPP): Total rate of photosynthetic energy capture.

Net Primary Productivity (NPP): GPP minus autotrophic respiration (Ra). NPP = GPP - Ra. NPP represents the biomass available to consumers.

Ch 15: NPP Comparisons & Limiting Factors -

Terrestrial NPP is highest in tropical rainforests (high temp, light, water); aquatic NPP is highest in coral reefs/estuaries, low in open ocean.

Limiting factors: Terrestrial = Temperature, moisture, nutrients (N, P). Aquatic = Light penetration, nutrients (N, P, Fe).

Ch 15: Energy Flow Efficiency & Food Chain Length -

~10% Ecological Efficiency: Only ~10% of energy moves to the next trophic level; 90% is lost to heat/respiration. This limits food chain length to 4-5 trophic levels.

Ch 15: Ecological Pyramids & Biological Magnification -

Pyramids of biomass/energy are upright in terrestrial systems, but biomass pyramids can be inverted in marine systems (phytoplankton turn over rapidly).

Biological Magnification: Toxins (e.g., DDT, mercury) concentrate at higher trophic levels.

Ch 16: Carbon Cycle Processes -

Photosynthesis (carbon fixation), Cellular Respiration, Decomposition, Combustion, Gas Exchange (ocean-atmosphere interface), and Sedimentation (fossil fuel/limestone formation).

Ch 16: Human Impacts on Global Carbon Cycle -

Burning fossil fuels (releases ancient stored carbon), deforestation (reduces carbon sink capacity), and industrial land development, leading to elevated atmospheric CO2 and ocean acidification.

Ch 19: Biodiversity Levels & Patterns -

Levels: Genetic diversity, Species diversity, Ecosystem diversity.

Latitudinal Gradient: Biodiversity is highest near the equator (tropics) and decreases toward the poles.

Ch 19: Biodiversity Hotspots & Extinction Rates -

Hotspots: Regions with high endemic species counts experiencing severe habitat loss (e.g., Madagascar, Tropical Andes). Current extinction rates are 100-1000x higher than background rates, marking the 6th mass extinction.

Ch 19: Five Greatest Threats (HIPPO):

Habitat loss,

Invasive species,

Pollution,

Population growth (human),

Overharvesting.

Importance to Humans: Ecosystem services, medicines, food security, climate regulation, intrinsic/aesthetic value.

Ch 20: Proximate vs. Ultimate Causation

Proximate Causation: "How" a behavior occurs (environmental stimuli, physiological/genetic mechanisms).

Ultimate Causation: "Why" a behavior evolved (evolutionary significance, adaptive value for survival/reproduction).

Ch 20: Innate vs. Learned Behaviors -

Innate: Developmentally fixed, hardwired behaviors without prior experience (e.g., fixed action patterns, reflexes).

Learned: Modified behaviors resulting from specific environmental experiences (e.g., operant conditioning, imprinting, spatial learning).

Ch 20: Behavioral Interactions (Interaction of Genes & Learning)

Behaviors like migration, foraging, and song development rely on genetic programs (innate inclination/capacity) refined by environmental cues and trial-and-error experience (learning).

Ch 20: Mating Systems & Selection Types - Mating Systems & Selection Types:

Monogamy (one male, one female),

Polygyny (one male, multiple females),

Polyandry (one female, multiple males).

Intrasexual Selection (competition within same sex, e.g., buck fights),

Intersexual Selection (mate choice between sexes, e.g., peacock tail display).

Ch 20: Inclusive Fitness & Kin Selection - Inclusive Fitness:

Total reproductive output including direct fitness (own offspring) and indirect fitness (relatives' offspring). Kin Selection: Evolutionary strategy favoring altruistic behavior towards genetic relatives, governed by Hamilton's Rule: rB > C (where r = relatedness, B = benefit, C = cost).