Bio 172 unit 2 exam

Ecosystem

includes all organisms that live in a particular place, plus the abiotic environment in which they live and interact

Biogeochemical Cycles

chemicals moving through ecosystems; biotic and abiotic processes

Methanogens

produce methane (CH4) by anaerobic cellular respiration

Carbon Fixation

metabolic reactions that make nongaseous compounds from gaseous ones (plants)

groundwater

water found underground

Aquifers

permeable, underground layers of rock, sand, and gravel saturated with water

Nitrogen Cycle

Synthesis of nitrogen-containing compounds from N2

Trophic Levels

where an organism feeds

Autotrophs

self feeders synthesis organic compounds from inorganic precursors

Photoautotrophs

autotrophs that use light as their source

Chemoautotrophs

autotrophs that use energy from inorganic oxidation reactions (prokaryotic)

Heterotrophs

cannot synthesize from inorganic precursor therefore eat others such as animals eat plants and other animals

Herbivores

first consumer level

Primary Carnivores

eat herbivores

Secondary Carnivores

eat primary carnivores or herbivores

Detrivores

eat decaying matter

Decomposers

microbes that break up dead matter

Productivity

the rate at which the organisms in the trophic level collectively synthesize new organic matter

Primary Productivity

productivity of the primary producers

Respiration

rate at which primary producers break down organic compounds

Gross Primary Productivity (GPP)

raw rate at which primary producers synthesize new organic matter

Net Primary Productivity (NPP)

is the GPP minus the respiration of the primary producers

Secondary Productivity

productivity of a heterotroph trophic level

Limits on Top Carnivores

exponential decline of chemical-bond energy limits the lengths of trophic chains and the numbers of top carnivores an ecosystem can support

Trophic Cascade

an effect exerted at an upper level flow down to influence two or more levels

Conservation Biology

an integrative discipline that applies the principles of ecology to the conservation of biodiversity

Endemic Species

species found naturally in only one geographic area and no place else; area may be very large or quite small

Biodiversity Hotspots

found in: areas of high species diversity, isolated islands, regions with diversification rate

Pleistocene Refugia Hypothesis

diversity is due to allopatric speciation brought on by isolation

Evolutionary-inspired Hypothesis

high rates of speciation in transition zones between different types of habitats

Ecosystem Services

natural processes that sustain life and you get it from nature free of cost

Ecology

study of how organisms relate to one another and to their environments

Physiological Responses

sweating, increased erythrocyte production, storing glycerol “antifreeze” in tissues

Morphological Capabilities

Endotherms have adaptations that minimize energy expenditure; thick fur coats during the winter

Behavioral Responses

moving from one habitat to another; maintain body temperature

Allen’s Rule of reduced surface area

mammals from colder climates have shorter ears and limbs

Populations

groups of individuals in the same species in one place/time

Dispersal Mechanisms

Animals colonize distant islands due to individuals or eggs floating or drifting on vegetation

Uniform Spacing

behavioral interactions; resource competition

Random Spacing

individuals do not interact strongly with one another and resources abundant; not common in nature

Clumped Spacing

uneven distribution of resources (biological, mineralogical, hydrological); common in nature

Population Demography

quantitative study of populations

Generation Time

average interval between birth and birth of its offspring

Fecundity Rate

birth rate

Mortality Rate

death rate

Type 1 Survivorship Curve

mortality rates rise steeper later in life

Type 2 Survivorship Curves

individuals likely to die at any age

Type 3 Survivorship Curve

produce many offspring and many die but once they become establishes, mortality rate decreases

Life Table

tabulates (follows) the fate of a cohort from birth until death showing number of offspring and number of deaths

Semelparity

focus all resources on one reproductive event and die

Iteroparity

produce offspring several times over many seasons

Biotic Potential (Exponential)

there are no limits on population growth; dN/dt=riN; dN/dt= rate of change over time; N=number of individuals in populations; ri= innate capacity for growth

Carrying Capacity (K)

the maximum number of individuals that the environment can support

Population Density-Dependent Factors

affect the population and depend on population size

Population Density-Independent Factors

affect populations regardless of size (such as natural disasters)

Allee Effect

growth rates increase with population size due to many factors (exp: locusts)

K-Selected Populations

adapted to thrive when population is near its carrying capacity

r-Selected Populations

selection favors individuals with the highest reproductive rates