exam 4 (final) Flashcards
autotrophs
produce their own food supply (producers, photosynthesizers, plants)
heterotrophs
consume energy from others
- primary: herbivores that eat autotrophs
- secondary: carnivores that consume primary
- tertiary: carnivores that consume secondary
net primary production
the energy stored in the autotrophs of an ecosystem over a given time period, determines energy that the ecosystem can support
- expressed in terms of dry weight of biological material (biomass / sq. m / yr)
aquatic food chains
- producers: phytoplankton
- primary consumers: zooplankton
detritivores
feed on wastes, dead bodies, and discarded parts
decomposers
secrete digestive enzymes that break down organic material and then absorb some resulting nutrients
energy pyramid
illustrates energy relationships between each trophic level (Rule of 10: only 10% passed to the next level, very inefficient)
biological magnification
increasing accumulation of toxic substances in progressively higher trophic levels
nutrients
atoms and molecules that organisms obtain from their environment, do not increase or decrease on earth, but simply cycles
nutrient cycles
pathways of a specific nutrient through the living and nonliving portions of an ecosystem
reservoir
when nutrients accumulate in one portion of their cycle
ecosystem
all organisms and nonliving environment in an area
ecology
how organisms interact with each other and their environment
growth rate (r)
birth rate - death rate
change in population size
(births - deaths) + (immigrants - emigrants)
birth rate (b)
of births/individual/time
death rate (d)
of deaths/individual/time
population growth per unit time (G)
growth rate x population size (N)
competition
both species lose
competitive exclusion principle
no two species can simultaneously and continuously occupy the same ecological niche
- competitive exclusion: one species outcompetes another to drive it to extinction
resources partitioning
using different parts of a resource to avoid competition
predation
one species wins (by consuming) , the other loses
parasitism
one species wins (by living on the host) , the other loses
mutualism
two species do better together than apart
keystone species
one species that determines the “health” of the community
symbiosis
when two species share a close long-term physical association (may be positive or not, not symbiotic if it’s short term)
camouflage
coloration/shape makes an organism inconspicuous in its environment
warning coloration
coloration/shape that makes prey conspicuous as a warning sign to potential prey
mimicry
species evolve to resemble another
- mullerian: two poisonous or distasteful species share similar warning pattern
- batesian: harmless animals resemble venomous/distasteful ones
- startle: color patterns that resemble the eyes of a larger/dangerous animal
- aggressive: predators resemble something attractive to prey
primary succession
a new community develops from no remnants of a prior community
secondary succession
a new community develops from remnants of a previous community
subclimax community
doesn’t reach climax stage, but is maintained at a less developed stage due to disturbances
climax community
a diverse and relatively stable community that forms at the endpoint of succession
environmental resistance
all living and nonliving factors that limit population growth
invasive species
species w high biotic potential that have been introduced into ecosystems in which they did not evolve and where they encounter little environmental resistance
carrying capacity (K)
max population size that can be sustained without damage to an ecosystem
logistic population growth
when population reaches carrying capacity, stabilizes, S-curve
biotic potential
max rate of increase of population
exponential growth
more births than deaths, reproduce more than replacement, J-curve
factors that influence exponential growth
- age of first production
- frequency of reproduction
- number of offspring in each reproductive event
- reproductive life span
- death rate under normal conditions
boom/bust cycles
huge population growth followed by huge crash
density-independent
population reaches carrying capacity regardless of size
density-dependent
population reaches carrying capacity based on availability of resources, effects are compounded by increases in population density
interspecific competition
between individuals of different species
intraspecific competition
between individuals of the same species
clumped population distribution
organisms live in groups, based on resources and
uniform population distribution
usually stable amount of distance between individuals, based on evenly distributed resources, territorial organisms
random population distribution
organisms organized randomly, no social groups, resources aren’t limited
early loss survivorship pattern
high numbers of offspring, little or no parental care, death rate is high on young offspring
constant loss survivorship patterns
equal chance of dying at any age
late loss survivorship patterns
most deaths occur late in life, tremendous amount of parental care, small numbers of offspring
innate behavior
completed correctly the first time without instruction, nature
learned behavior
requuires experience to complete, habits, nurture, can be modified
habituation
getting “used” to a stimulus, can be advantage or disadvantage
conditioning
trial and error, reward and punishment
insight
problem solving without experience
imprinting
learning only at a specified point in development
pheromones
chemical signals between same species
territories
individuals defend a resource area
types of communication
- visual: short distances
- audio: long distances
- chemical: long lasting
- touch: social bonding
