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

Ecotones

places where the environment changes abruptly due to the environment differing in resources, climate, etc.

Niche

a place or status etc. thats best fitted or very suitable; the total of all the ways an organism uses the resources of its environment to reproduce and survive

Fundamental Niche

the entire niche that a species is capable of using based on its physiology and resource needs

Realized Niche

the actual set of environmental conditions (presence absence of other species) that the species can establish a population

Competition

occurs when individuals of the same or different species share the use of resource that limits the growth, survival, and reproduction of each

Intraspecific Competition

competition between the individuals of the same species

Interspecific Competition

competition between different species that use the same resources but there is not enough resources to satisfy both

Interference

physical interactions over access to resources

Exploitative

individuals are consuming the same resources indirectly, leading to competition for availability.

Mimicry

allows one species to capitalize on defensive strategies of another

Batesian Mimicry

mimics look like distasteful model

Mullerian Mimicry

several unrelated but poisonous species come to resemble one another

Symbiosis

2 or more kinds of organisms interact in more-or-less permanent relationships

Commenalism

symbiosis resulting in organisms eating at the same table

Mutualism

symbiosis that benefits both species involved

Parasitism

symbiosis in which only one species benefits

Ectoparasites

feed on exterior surface of an organism

Parasitoids

insects that lay eggs on living hosts

Endoparasites

live inside of the host organism

Succession

communities have a tendency to change from simple to complex

Primary Succession

a habitat that never had any biological component

Secondary Succession

occurs in areas where an existing community has been disturbed but organisms still remain

Establishment

early successional species are characterized by r-selected species tolerant of harsh conditions (Stage 1 of Succession)

Facilitation

early successional species introduce local changes in the habitat K-selected species replace r-selected species (Stage 2 of Succession)

Inhibition

changes in the habitat caused by one species inhibits the growth of the original species (Stage 3 of Succession)

Intermediate Disturbance Hypothesis

communities experiencing moderate amounts of disturbance will have higher levels of species richness than communities experiencing either little or great amounts of disturbance

Conformers

animals and plants that equilibrate to the conditions of their environment; their bodies adopt the temperature, salinity, or other physiological aspects of their surroundings

Norm of Reaction

The ability of an individual to use its genotype to produce multiple phenotypes in response to specific environmental conditions

Metapopulation

a network of distinct populations that may exchange individuals

Cohort

a group of organisms of the same age

Cost of Reproduction

what ecologists refer to as the reduction in future reproductive potential resulting from current reproductive efforts

Logistic Growth

the pattern in which population growth slows down as it approaches the carrying capacity

Species richness

the number of different species in a community

Competitive Exclusion

when one species drives another to extinction because it more effectively utilizes a common resource

Resource Partitioning

the differentiation of niches, in both space and time, enabling similar species to coexist in a community

Character Displacement

the tendency for two species to diverge in morphology and thus resource use (which will minimize competition)

Keystone Species

Species that have a disproportionately high impact on a community

Top-down Effect

when a higher trophic level in an ecsystem influences a lower trophic level through predation

Bottom-up Effect

when changes in the population of a lower trophic level in a food chain significantly impact the populations at higher trophic levels